Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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Foam properties of proteins, low molecular weight surfactants and their complexes
Lech, F.J. - \ 2016
Wageningen University. Promotor(en): Harry Gruppen; Peter Wierenga; Marcel Meinders. - Wageningen : Wageningen University - ISBN 9789462576247 - 122 p.
surfactants - proteins - bovine serum albumin - beta-lactoglobulin - lysozyme - foams - chemical properties - stability - mixtures - food chemistry - oppervlaktespanningsverlagende stoffen - eiwitten - runderserumalbumine - bèta-lactoglobuline - lysozym - schuim - chemische eigenschappen - stabiliteit - mengsels - voedselchemie

This thesis shows the effects that the addition of low molecular weight surfactants (LWMS) to proteins has on the foam stability of the mixture. For this, the bulk, interfacial, thin liquid films and foam properties are determined for different protein-LWMS mixtures at different molar ratios (MR). It was shown that the MR as well as the charge of the protein and LMWS determine the foam stability of the mixtures. For all mixtures it was found that the proteins have a select number of high affinity binding sites. So, the concentration of free LMWS in the solution is 0 until a critical MR (MRcr), at which all high affinity binding sites are saturated. Above this MRcr, part of the LMWS binds to low affinity binding sites of the proteins. The low affinity binding sites have a binding ratio < 1, which determines the concentration of bound and free LMWS. For similarly charged protein-LMWS mixtures (i.e. b-lactoglobulin (BLG) and sodium dodecyl sulphate (SDS) and bovine serum albumin (BSA) and SDS at pH 7) the foam stability typically decreases from the foam stability of the pure protein solution (MR 0) until MRcr is reached. At MR > MRcr the foam stability is dominated by the amount of free LMWS. For oppositely charged protein-LMWS mixtures, the binding of the LMWS to the proteins can be described in a similar way, although the number of high affinity sites and low affinity binding ratio are different. There is also a regime of MRs in which the protein-LMWS complexes form large aggregates. These aggregates were in some cases found to increase foam stability (lysozyme (LYS) and SDS and BLG-SDS at pH 3), while in another case (BLG and cetyltrimethylammonium bromide (CTAB)) they lead to decreased foam stability. Still, in all cases it was found that above MRD the aggregates dissociate and the foam stability becomes dominated by free surfactants, equivalent to what was observed for similarly charged protein-LMWS mixtures.

A multi-scale model was developed to describe the stability of thin liquid films in terms of rupture time and thickness. Initially, the model was used to predict the stability of surfactant free films of water and electrolyte solutions. Later, it was used to predict the foam stability in LYS-SDS mixtures. For that purpose, the model was combined with a foam drainage model to provide theoretical estimations of foam stability. This model is the basis to understand coalescence of bubbles in foam. Finally, the concept of the critical MRs and the free LMWS was introduced. Using this, the foam properties of protein-LMWS mixtures can partly be predicted by relative charge of the components and the binding to both high and low affinity binding sites.

Baseline survey B11-5 on the German Continental Shelf
Glorius, S.T. ; Weide, B.E. van der; Kaag, N.H.B.M. - \ 2013
Den Helder : IMARES (Rapport / IMARES Wageningen UR C098/13) - 45
waterbodems - noordzee - chemische eigenschappen - fysische eigenschappen - biologische eigenschappen - sediment - textuur - inventarisaties - water bottoms - north sea - chemical properties - physical properties - biological properties - texture - inventories
A consortium, consisting of Wintershall Holding GmbH, GdF Suez, RWE Dea and EWE AG, is planning an exploration well in block B11-5, located within the Doggerbank (N2000 area). In order to assess any effect from this activity on the biological, physical and chemical properties of the seafloor Wintershall Noordzee BV asked IMARES to perform a baseline study prior to the drilling activities. In this baseline study the following environmental elements are included; seafloor texture and presence of any structures (including stones and boulders), the physical (grain size and organic content), chemical (oil and metal content) and biological (abundance and structure of benthic species) properties of the sediment. At 29 stations located at different angles and distances of the drill site, sediment samples were taken and video recordings of the seafloor made. In an area of 2000 x 2000 m around the centre, side scan sonar footage were made as well.
Abiotische randvoorwaarden en natuurdoelen in kunstmatige wateren dl. 3 Matige grote, ondiepe laagveenplassen
Keizer-Vlek, H.E. ; Lange, H.J. de; Verdonschot, P.F.M. - \ 2010
Wageningen : Alterra (Alterra-rapport 2089) - 88
laagveengebieden - plassen - fauna - vissen - waterplanten - oppervlaktewater - biologische indicatoren - zoetwaterecologie - habitats - chemische eigenschappen - waterkwaliteit - nederland - kwaliteit - macrofauna - kaderrichtlijn water - natura 2000 - abiotiek - fens - ponds - fishes - aquatic plants - surface water - biological indicators - freshwater ecology - chemical properties - water quality - netherlands - quality - water framework directive - abiotic conditions
Het doel van deze studie is het gekwantificeerd invullen van de abiotische randvoorwaarden behorende bij de (Zeer) Goede Ecologische Toestand ((Z)GET) van het KRW type M27 ‘Matig grote, ondiepe laagveenplassen’. Meetgegevens van de twaalf ‘best beschikbare’ plassen in Nederland zijn voor dit doel geanalyseerd. De resultaten geven aan dat de biologische kwaliteitselementen in geen van de twaalf plassen voldoen aan de GET. De relatief slechte ecologische toestand van de plassen wordt onder andere veroorzaakt door hoge concentraties totaal-stikstof en totaal-fosfor, beperkt doorzicht en een hoge pH. Deze abiotische variabelen voldoen in bijna alle gevallen niet aan de GET-norm. De resultaten van het onderzoek impliceren dat de GET-norm/KRW referentie¬waarde(n) voor de abiotische variabelen EGV, chloride, ammonium en sulfaat naar beneden moeten worden bijgesteld om de GET van matig grote, ondiepe laagveenplassen te kunnen garanderen. Voor deze abiotische variabelen moet echter eerst nog worden bepaald of hogere concentraties dan vastgesteld in dit onderzoek leiden tot een verminderde ecologische toestand. Verder zal meer inzicht moeten komen in de voor de macrofauna- en waterplantengemeenschap sturende factoren door middel van experimenteel onderzoek. Hiervoor is naast informatie over fysisch-chemische milieuvariabelen ook informatie nodig over hydro¬morfologische milieuvariabelen. Tot slot is niet mogelijk gebleken om op basis van deze studie een eenduidige relatie te leggen tussen de abiotische randvoorwaarden noodzakelijk voor de realisatie van de GET in matig grote, ondiepe laagveenplassen (KRW) en de abiotische randvoorwaarden noodzakelijk voor de realisatie van aquatische habitattypen (VHR). Wel is vastgesteld dat habitattype 3140 niet voorkomt in de onderzochte plassen, terwijl zes van de twaalf onderzochte plassen liggen in een Natura 2000-gebied met een doelstelling voor habitattype 3140.
Influence of pectin characteristics on complexation with ß-lactoglobulin
Sperber, B.L.H.M. - \ 2010
Wageningen University. Promotor(en): Fons Voragen; Willem Norde, co-promotor(en): Henk Schols. - [S.l. : S.n. - ISBN 9789085858355 - 174
pectinen - bèta-lactoglobuline - ladingskenmerken - fysische eigenschappen - chemische eigenschappen - binding (scheikundig) - pectins - beta-lactoglobulin - charge characteristics - physical properties - chemical properties - bonding
Pectin and proteins are both common food constituents. The type of pectin that forms complexes with protein is known to be of great influence on the structure and stability of liquid foods. Therefore, the aim of this thesis is to investigate the influence of the overall charge and local charge density of pectin on the formation of soluble complexes with β-lactoglobulin (β-lg).
Combination of state diagrams and binding isotherms shows that a high local charge density of pectin is a prerequisite to form soluble complexes with β-lg at higher ionic strength. A high overall charge of pectin results in the close proximity of the GalA blocks. Therefore, β-Lg neighbours bind close together on pectin with a high overall charge, which leads to lateral repulsion and hence, maxima in the binding constant and the pH where insoluble complexes form with increasing ionic strength.
The formation of soluble complexes has an enthalpic driving force from electrostatic attraction and an entropic driving force from the release of small counterions from the electric double layer and water molecules from hydrophobic surroundings. A high local charge density, at low ionic strength results in complex formation dominated by an enthalpic driving force. A low local charge density gives a more even distribution between enthalpic and entropic contributions. An increase in ionic strength decreases the enthalpic contribution, with a relative increase in the entropic contribution, supporting the idea of water release from hydrophobic surroundings.
Adsorption from β-lg–pectin mixtures to a hydrophobic surface leads to low adsorption rates due to a low concentration of free protein. Sequential adsorption of β-lg and pectin shows that low overall charge pectin protrudes more into the solution than high overall charge pectin, resulting in a more negative ζ-potential for low overall charge pectin. After sequential adsorption, β-lg is most stable against wash-out with a terminal pectin layer.
Coffee brew melanoidins Structural and Functional Properties of Brown-Colored Coffee Compounds
Bekedam, E.K. - \ 2008
Wageningen University. Promotor(en): Gerrit Smit; Tiny van Boekel, co-promotor(en): Henk Schols. - [S.l.] : S.n. - ISBN 9789085049517 - 168
koffie - kleurstoffen in voedsel - roosteren - chemische eigenschappen - coffee - food colourants - toasting - chemical properties
The aim of the work presented in this thesis was the identification of structural and functional properties of coffee brew melanoidins, and their formation mechanisms, that are formed upon roasting of coffee beans.
H-Bond stabilized columnar discotic liquid crystals
Paraschiv, I. - \ 2007
Wageningen University. Promotor(en): Ernst Sudhölter, co-promotor(en): Ton Marcelis; Han Zuilhof. - [S.l.] : S.n. - ISBN 9789085045588 - 150
chemische eigenschappen - synthese - vloeibare kristallen - organische scheikunde - chemical properties - synthesis - liquid crystals - organic chemistry
Lignin as additive in paper production
Gosselink, Richard - \ 2005
lignin - properties - strength - quality - pulps - fibres - chemical properties - lignosulfonates - biobased economy - papermaking
Studies on the intra- and intermolecular distributions of substituents in commercial pectins
Guillotin, S.E. - \ 2005
Wageningen University. Promotor(en): Fons Voragen, co-promotor(en): Henk Schols. - [S.l.] : S.n. - ISBN 9085042658 - 155
pectinen - chemische eigenschappen - fysische eigenschappen - voedseladditieven - pectins - chemical properties - physical properties - food additives
Commercial pectins are mainly used for the gelling, thickening and stabilizing properties in food products. The different physical properties of pectins strongly depend on the galacturonic acid level and the level of methyl-esterification as well as on the molecular weight distribution. However, the conventional chemical analysis of the pectins does not always show differences between pectins while they behave differently. Two highly methyl-esterified pectins with similar chemical characteristics but different reactivity towards calcium were analysed. They were found to be a mixture of pectic populations differing in the degree of methyl-esterification as well as in the distribution of these methyl-esters. Amidated pectins with similar chemical features but different calcium sensitivity were also found to be a mixture of different pectic populations. Even for pectins having a similar degree of substitution, the ratio of amide groups versus methyl-esters varied significantly. In addition, the distribution of these substituents was found to differ.
Podzolisation and soil organic matter dynamics
Buurman, P. ; Jongmans, A.G. - \ 2005
Geoderma 125 (2005)1-2. - ISSN 0016-7061 - p. 71 - 83.
methylation-mass spectrometry - podzol formation - southern queensland - chemical properties - size fractions - forest soils - bh horizons - aluminum - carbon - podzolization
Present models of podzolisation emphasize the mobilization and precipitation of dissolved organic matter. together with Al(-silicates) and Fe. Such models cannot explain the dominance of pellet-like organic matter in most boreal podzols and in well-drained podzols outside the boreal zone, and the discrepancy between the chemistry of percolating organic matter (DOC) and the organic matter accumulated in well-drained podzol-B horizons. The present paper offers an amended podzolisation theory, in which relative contribution of illuviated organic matter and root litter together with organic matter dynamics provide an explanation for the large variation in podzol morphology, It is suggested that fast organic matter dynamics as occurs on nutrient-rich parent materials in the boreal zone causes small accumulation of organic matter, mainly derived from roots. In such soils. the colors of Fe components dominate in the B horizon. Slow organic matter dynamics, as occurs on nutrient-poor parent materials and under hydromorphic circumstances, favors large organic matter accumulations in the B horizon. and a larger abundance of DOC-derived organic matter coatings. The latter group includes tropical podzols. (C) 2004 Elsevier B.V. All rights reserved.
Effects of different treatments of cattle slurry manure on water-extractable phosphorus
Chapuis-Lardy, L. ; Temminghoff, E.J.M. ; Goede, R.G.M. de - \ 2003
Netherlands Journal of Agricultural Science 51 (2003)1-2. - ISSN 0028-2928 - p. 91 - 102.
rundveemest - rundveedrijfmest - behandeling - fosfor - toevoegingen - oplosbaarheid - chemische eigenschappen - waterverontreiniging - mestverwerking - cattle manure - cattle slurry - treatment - phosphorus - chemical properties - additives - solubility - water pollution - manure treatment - runoff phosphorus - animal manure - nitrogen - soil - netherlands - strategies - management - excretion - recovery - losses
Cattle slurry manure applied to land increases the risk of phosphorus (P) movement to surface waters, which may lead to eutrophication. The water-extractable fraction of P in slurry manure is correlated with P concentration in runoff from soils amended with slurry smanure, and thus is an effective indicator of environmental P loss. We evaluated the water-extractable P (WEP) and readily soluble P (RSP; i.e., P extractable in a single water extract) contents in slurry manure from nine farms. On some farms, the additive Euromestmix® (MX) is used to complex N-compounds in the slurry manure, but the effect of MX on P in the slurry manure is not known. We also focused on methodological factors affecting the measurement of P in slurry manure. Drying the slurry manure before analysis decreased WEP and RSP contents. Dilution of slurry manure by varying the dry matter-to-distilled water ratio increased the water-extractable fractions. Analysis of calcium and magnesium contents in water showed that these minerals are involved in the release of P in water. Total RSP content of slurry manures from the nine farms ranged from 1.83 to 4.06 mg P per g dry matter. A substantial portion of total P in the slurry manure occurred in the water-extractable (46–71%) and the readily soluble P fractions (24–51%). The addition of MX tended to decrease the readily soluble inorganic P content of slurry manures.
Ambergris fragrance compounds from labdanolic acid and larixol
Bolster, M.G. - \ 2002
Wageningen University. Promotor(en): Æ. de Groot; B.J.M. Jansen. - S.l. : S.n. - ISBN 9789058086662 - 214
diterpenen - welriekendheid - aromatische verbindingen - biosynthese - chemische eigenschappen - oxidatie - biologische eigenschappen - diterpenes - fragrance - aromatic compounds - biosynthesis - chemical properties - oxidation - biological properties
<FONT FACE="Arial" SIZE=3><p>Since ancient times, ambergris has been one of the most highly valued perfumery materials. Ambergris is a metabolic product of the spermwhale ( <em>Physeter macrocephalus</em> L.), which accumulates as concretions in the gut. (-)-Ambrox<FONT FACE="Symbol">Ò</font>, the commercially most important constituent of natural ambergris, is recognized as the prototype of all ambergris odorants. For this reason, various synthetic routes to (-)-Ambrox<FONT FACE="Symbol">Ò</font>and its racemate have been developed, preferrably starting from cheap, abundantly available natural labdanes. Sclareol is nowadays the industrially used starting material for the preparation of (-)-Ambrox<FONT FACE="Symbol">Ò</font>. Labdanolic acid and larixol are both easily and abundantly available from labdanum gum of <em>Cistus ladaniferus L.</em> ("Rock-rose") and turpentine of the <em>Larix decidua</em> , respectively, but have found little use as starting material in syntheses of Ambergris odour compounds. In this thesis new chemistry in that field is described.</p><p>From the acetate of labdanolic acid short procedures are developed for the synthesis of Ambrox<FONT FACE="Symbol">Ò</font>. Also a standard method has been developed for the oxidation of the side chain of several labdanes. Generally good to high yields of single products can be obtained using anhydrous potassium permanganate in the presence of a phase-transfer catalyst. In this way larixol can be converted into suitable synthons for the synthesis of several Ambrox-like compounds. 6</font><FONT FACE="Symbol" SIZE=3>a</font><FONT FACE="Arial" SIZE=3>-hydroxy Ambrox can be considered to be a key intermediate in such syntheses and conversions of larixol into this intermediate are described. From 6</font><FONT FACE="Symbol" SIZE=3>a</font><FONT FACE="Arial" SIZE=3>-hydroxy Ambrox a number of simple Ambrox derivatives have been synthesized. By heating with acid a mixture was formed consisting of</font><FONT FACE="Symbol" SIZE=3>D</font><sup><FONT FACE="Arial" SIZE=3>5</SUP>- and</font><FONT FACE="Symbol" SIZE=3>D</font><sup><FONT FACE="Arial" SIZE=3>6</SUP>-Ambroxene, which both are pleasant smelling.</font><FONT FACE="Symbol" SIZE=3>D</font><sup><FONT FACE="Arial" SIZE=3>5</SUP>-Ambroxene was produced in a more selective way by elimination of methanesulfonic acid from the corresponding mesylate of 6</font><FONT FACE="Symbol" SIZE=3>a</font><FONT FACE="Arial" SIZE=3>-hydroxy Ambrox. A selective synthesis of</font><FONT FACE="Symbol" SIZE=3>D</font><sup><FONT FACE="Arial" SIZE=3>6</SUP>-Ambroxene proved to be more difficult and laborious. Several approaches were investigated, and ultimately the one <em>via</em> ringclosure of an allylic alcohol proved to give good results. It turned out that this new approach could not be extended to the <em>selective</em> synthesis of six-membered cyclic ethers, <em>e.g.</em><FONT FACE="Symbol">D</font><sup>6</SUP>-Ambra oxides. In the latter case, elimination of the 6<FONT FACE="Symbol">b</font>-hydroxyl group to the corresponding<FONT FACE="Symbol">D</font><sup>6,8</SUP>-dienes was observed as the major reaction.
Measuring acid volatile sulphide in floodplain lake sediments: effect of reaction time, sample size and aeration
Griethuysen, C. van; Gillissen, F. ; Koelmans, A.A. - \ 2002
Chemosphere 47 (2002). - ISSN 0045-6535 - p. 395 - 400.
bodemchemie - chemische eigenschappen - sulfiden - analyse - laboratoriumdiagnose - sediment - meren - waterbodems - soil chemistry - lakes - chemical properties - sulfides - analysis - laboratory diagnosis - water bottoms
Zelfcontrole stikstofgit levert besparingen op
Brouwer, J. ; Derkx, M.P.M. - \ 2001
De Boomkwekerij 14 (2001)18. - ISSN 0923-2443 - p. 18 - 19.
bosbouw - plantenvoeding - stikstof - stikstofmeststoffen - mestbehoeftebepaling - analyse - chemische eigenschappen - bodem - fraxinus excelsior - bos- en haagplantsoen - forestry - plant nutrition - nitrogen - nitrogen fertilizers - fertilizer requirement determination - analysis - chemical properties - soil - woody nursery stock
Stikstofbemestingsadvies voor bos- en haagplantsoen: onderdeel van het project 'Innovatieve teelt van bos- en haagplantsoen'. Gegevens in bijgaande tabel en figuren: 1) N-min metingen in de bouwvoor bij verplante Fraxinus excelsior; 2) Restwaarden N-min in bodem (0-90 cm) bij verplante Fraxinus excelsior; 3) Maatverdeling bij verplante Fraxinus excelsior na drie methoden N-bemesting
Mineralenbalans en grondwaterkwaliteit bij deelnemers Bioveem
Snijders, P. ; Everts, H. - \ 2000
Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 13 (2000)6. - ISSN 1386-8470 - p. 31 - 33.
melkveehouderij - biologische landbouw - zandgronden - mineralen - boekhouding - grondwater - chemische eigenschappen - nitraten - dairy farming - organic farming - sandy soils - minerals - accounting - groundwater - chemical properties - nitrates
Het nitraatgehalte in het grondwater voldoet aan de EU norm van 50 mg per l. Ook het stikstof en fosfaat overschot op de mineralenbalans voldoet op de meeste bedrijven.
Hormoonontregelaars in water opsporen met biologische effectmetingen
Murk, A.J. ; Belfroid, A. ; Vethaak, D. - \ 2000
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 33 (2000)1. - ISSN 0166-8439 - p. 20 - 23.
toxische stoffen - hormonen - geslachtshormonen - oestrogenen - synthetische oestrogenen - oestrogene eigenschappen - waterverontreiniging - waterkwaliteit - oppervlaktewater - afvalwater - rioolwater - samenstelling - eigenschappen - chemische eigenschappen - chemische analyse - tests - testen - assays - in vitro - Nederland - xenobiotica - toxic substances - hormones - sex hormones - oestrogens - synthetic oestrogens - oestrogenic properties - water pollution - water quality - surface water - waste water - sewage - composition - properties - chemical properties - chemical analysis - testing - Netherlands - xenobiotics
Uitleg over de pricipes van verschillende in-vitro testen gebruikt voor het bepalen van de oestrogene potentie van monsters oppervlaktewater en afvalwater, en enige resultaten voor verschillende locaties in Nederland
Dioxinetest RIKILT heeft zijn waarde bewezen
Mengelers, M.J.B. ; Hoogenboom, L.A.P. ; Traag, W.A. - \ 1999
Voedingsmiddelentechnologie 4 (1999)23. - ISSN 0042-7934 - p. 13 - 16.
dioxinen - heterocyclische zuurstofverbindingen - analytische methoden - testen - controle - kwalitatieve analyse - toxische stoffen - chemische samenstelling - chemische eigenschappen - voedselbesmetting - voedingsmiddelen - voedselindustrie - voedseltechnologie - analytische scheikunde - dioxins - heterocyclic oxygen compounds - analytical methods - testing - control - qualitative analysis - toxic substances - chemical composition - chemical properties - food contamination - foods - food industry - food technology - analytical chemistry
Sinds 1992 werkt het Rikilt in samenwerking met de Wageningen Universiteit aan een biologische methode voor het screenen van agrarische producten op dioxinen en dioxineachtige PCB's. De methode is gevalideerd voor het aantonen van dioxinen in melk en in citruspulp uit Brazilie
The use of upscaling procedures in the application of soil acidification models at different spatial scales
Vries, W. de; Kros, J. ; Salm, C. van der; Groenenberg, J.E. ; Reinds, G.J. - \ 1998
Nutrient Cycling in Agroecosystems 50 (1998)1-3. - ISSN 1385-1314 - p. 223 - 236.
zure gronden - kattekleigronden - neerslag - chemische eigenschappen - zuurgraad - zure regen - modellen - onderzoek - geostatistiek - acid soils - acid sulfate soils - precipitation - chemical properties - acidity - acid rain - models - research - geostatistics
Different soil acidification models have been developed for use on different scales, i.e., NUCSAM for the local scale, RESAM for the regional (national) scale and SMART for the continental scale. This paper focuses on the uncertainties associated with scale transfer by a simpler model description by (i) temporal aggregation of process descriptions, (ii) neglection of processes associated with vertical aggregation of soil layers and (iii) the use of less detailed formulations of processes (process aggregation) and by spatial aggregation of input data. Results obtained for simulations in acid (sandy) soils indicate that (i) temporal aggregation and process aggregation have a limited impact on the long-term (decades) annual response of soil solution chemistry to atmospheric deposition, (ii) vertical aggregation mainly affects predictions of solutes which show a strong concentration gradient with depth and (iii) spatial aggregation hardly affects the average output for a given forest/soil combination. However, ignoring the variability in input parameters, largely affects the frequency distribution of model outputs in a region. Results imply that model simplification is an adequate step in the upscaling of modelling results from a local to a regional scale.
Assessment of weathering rates in Dutch loess and river-clay soils at pH 3.5, using laboratory experiments
Salm, C. van der; Köhlenberg, L. ; Vries, W. de - \ 1998
Geoderma 85 (1998). - ISSN 0016-7061 - p. 41 - 62.
zware kleigronden - lössgronden - bodemvorming - chemische eigenschappen - fysicochemische eigenschappen - nederland - clay soils - loess soils - soil formation - chemical properties - physicochemical properties - netherlands
Weathering rates in 12 horizons of soils developed in loess and clay sediments were measured by means of laboratory experiments. The experiments were carried out by percolating thin columns containing approximately 2 g of soil material. Despite the small amount of sample used, the results were fairly reproducible. Weathering rates in loess soils were 0.8 to 8 times higher than rates measured in sandy soils. The rates in river-clay soils were 4 to 90 times the rates in sandy soils. The weathering rates of the base cations (BC), especially Ca and Mg, strongly increased with clay content. Significant relations were found between the mineralogical composition, total element content and texture characteristics of the samples and the measured weathering rates.
Exposure of non-target plants to pesticides: a review on atmospheric concentrations and no-effect levels with special attention for herbicide vapours
Kempenaar, C. ; Tonneijk, A.E.G. ; Eerden, L.J. van der - \ 1998
Wageningen : AB-DLO - 20
gewasbescherming - pesticiden - herbiciden - lucht - hygiëne - luchtverontreiniging - neerslag - chemische eigenschappen - zuurgraad - zure regen - chemische samenstelling - planten - chemische analyse - plant protection - pesticides - herbicides - air - hygiene - air pollution - precipitation - chemical properties - acidity - acid rain - chemical composition - plants - chemical analysis
Optimale meetnetdichtheid van routinematige fysisch-chemische waterkwaliteitmeetnetten.
Blind, M.W. ; Wiele, P.J. van der; Aalderink, R.H. - \ 1998
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 31 (1998). - ISSN 0166-8439 - p. 89 - 91.
oppervlaktewater - fysische eigenschappen - chemische eigenschappen - waterkwaliteit - monitoring - optimalisatiemethoden - surface water - physical properties - chemical properties - water quality - optimization methods
De uiteenzetting toont dat voor het uitvoeren van een meetnetdichtheidsanalyse consensus moet bestaan over wat verstaan wordt onder een optimale meetnetdichtheid. Uitgangspunt bij de ruimtelijke inrichting is dat de meetinspanning informatie moet opleveren
Gevolgen van het beperken van de waterinlaat en doorspoeling van het gebied Voorne-West : beknopte versie
Hamaker, Ph. ; Aarnink, W.H.B. ; Peerboom, J.M.P.M. - \ 1997
Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 435.2) - 52
hydrologie - wateraanvoer - waterbeheer - kanalen - oppervlaktewater - chemische eigenschappen - modellen - zuid-holland - glastuinbouw - zuidhollandse eilanden - hydrology - water advance - water management - canals - surface water - chemical properties - models - greenhouse horticulture
Gevolgen van het beperken van de waterinlaat en doorspoeling van het gebied Voorne - West : uitgebreide versie
Hamaker, P. ; Aarnink, W.H.B. ; Peerboom, J.M.P.M. - \ 1997
Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 435)
hydrologie - wateraanvoer - waterbeheer - kanalen - oppervlaktewater - chemische eigenschappen - modellen - zuid-holland - glastuinbouw - zuidhollandse eilanden - hydrology - water advance - water management - canals - surface water - chemical properties - models - greenhouse horticulture
Effecten van hydrologische maatregelen tegen verzuring en vermesting op vegetatie, bodem en grondwater in Groot Zandbrink; evaluatie na vijf jaar
Jansen, P.C. ; Kemmers, R.H. ; Delft, S.P.J. van; Knol, W.C. - \ 1997
Wageningen : DLO-Staring Centrum - 64
ecologie - hydrologie - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - neerslag - chemische eigenschappen - zuurgraad - zure regen - bodemchemie - anorganische verbindingen - mineralen - graslanden - nederland - ecohydrologie - gelderland - gelderse vallei - ecology - hydrology - rivers - streams - canals - surface water - water pollution - water quality - precipitation - chemical properties - acidity - acid rain - soil chemistry - inorganic compounds - minerals - grasslands - netherlands - ecohydrology
In het natuurreservaat Groot Zandbrink zijn greppels aangelegd in natte schraalgraslanden als maatregel tegen verzuring. Sinds 1991 worden de ontwikkelingen in vegetatie, bodem en grondwater gevolgd. Daartoe wordt ieder jaar de vegetatie gekarteerd enwordt de bodem om de twee jaar en het bodemwater ieder kwartaal bemonsterd. Op verschillende plekken bleek de maatregel in natte perioden effectief: de calciumverzadiging en het aandeel lithotroof water in de wortelzone nam toe, terwijl ook de bedekking met kwelafhankelijke plantensoorten groter werd. Tijdens de droge periode juni '95-oktober '96 zijn de veranderingen echter teniet gegaan. Verder toonde het onderzoek aan dat in vergelijking met de periode 1978-1981 de hoogste grondwaterstanden minder langdurig bereikt worden en de gemiddeld laagste grondwaterstand is gedaald.
Verzuring in Nederland; indirecte effecten
Erisman, J.W. ; Vries, W. de - \ 1997
Bodem 7 (1997)3. - ISSN 0925-1650 - p. 109 - 111.
bodem ph - bodemaciditeit - neerslag - chemische eigenschappen - zuurgraad - zure regen - nederland - soil ph - soil acidity - precipitation - chemical properties - acidity - acid rain - netherlands
Invloed van milieubedreigingen op de natuurwaarden van het Nederlandse bos. Basisdocument voor Natuurverkenning '97
Hendriks, C.M.A. ; Jansen, P.C. ; Schotman, A.G.M. ; Vries, F. de; Kemmers, R.H. ; Olsthoorn, A.F.M. ; Schaap, W. - \ 1997
Wageningen : SC-DLO (Rapport / DLO-Staring Centrum 413) - 104
bosbouw - achteruitgang, bossen - levensvatbaarheid - synecologie - milieu - verontreinigende stoffen - verontreiniging - nadelige gevolgen - verdroging - drogen - neerslag - chemische eigenschappen - zuurgraad - zure regen - forestry - forest decline - viability - synecology - environment - pollutants - pollution - adverse effects - desiccation - drying - precipitation - chemical properties - acidity - acid rain
Hydrologische maatregelen voor het herstel van blauwgrasland in de Bennekomse Meent.
Hoek, D. van de; Braakhekke, W.G. - \ 1997
De Levende Natuur 89 (1997). - ISSN 0024-1520 - p. 253 - 257.
plantengemeenschappen - vegetatie - onderzoek - regulatie - grondwater - chemische eigenschappen - ecologie - hydrologie - waterstand - ecohydrologie - gelderse vallei - plant communities - vegetation - research - regulation - groundwater - chemical properties - ecology - hydrology - water level - ecohydrology
Verslag van onderzoek in het kader van obn
Modellering van grondwaterkwaliteit : zin en onzin
Leijnse, A. - \ 1996
Wageningen : Landbouwuniversiteit Wageningen - 36
chemische eigenschappen - grondwater - grondwaterstroming - grondwaterverontreiniging - colleges (hoorcolleges) - modellen - nederland - verontreinigingsbeheersing - bescherming - waterkwaliteit - openbare redes - chemical properties - groundwater - groundwater flow - groundwater pollution - lectures - models - netherlands - pollution control - protection - water quality - public speeches
Validation and application of soil acidification models at local, national and European scale; a compilation of articles on the models NuCSAM, ReSAM and SMART
Kros, J. ; Groenenberg, J.E. ; Salm, C. van der; Vries, W. de; Reinds, G.J. - \ 1996
Wageningen : DLO Winand Staring Centre - 158
zure gronden - kattekleigronden - bosbouw - neerslag - zure regen - zure depositie - chemische eigenschappen - zuurgraad - modellen - onderzoek - acid soils - acid sulfate soils - forestry - precipitation - acid rain - acid deposition - chemical properties - acidity - models - research
An overview is given of three dynamic soil acidification models for application on different spatial scales. NUCSAM, the model for the local scale, was validated on data from two intensively monitored research sites. Results of annual average soil solution concentrations and fluxes calculated with the validated NUCSAM model agreed well with those of the national-scale model RESAM and to a lesser extent with those of the European-scale model SMART. Various deposition scenarios for SOx, NOx and NHx on soils were evaluated with the three acidification models.
Onderzoek en maatwerk voor verdrogingsbestrijding op het landgoed `De Wildenborch'
Reit, H.J. ; Jansen, P.C. ; Massop, H.T.L. ; Peerboom, J.M.P.M. - \ 1996
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 29 (1996)19. - ISSN 0166-8439 - p. 550 - 554.
chemische eigenschappen - ecologie - grondwater - grondwaterstand - hydrologie - regulatie - ecohydrologie - gelderland - waterstand - achterhoek - chemical properties - ecology - groundwater - groundwater level - hydrology - regulation - ecohydrology - water level
Op landgoed De Wildenborch zijn verdrogingssignalen waargenomen. Onderzoek van het ecohydrologisch systeem toonde aan dat de grondwaterstanden zijn gedaald en dat een belangrijk gedeelte van de diepe kwelflux wordt afgevangen door aangrenzende waterlopen. In de humusprofielen was de calciumbuffer op veel plaatsen nagenoeg op, waardoor de verzuring zal toenemen. Hydrologisch modelonderzoek had tot doel een scenario te formuleren voor een optimaal peilbeheer. Gekozen is voor het opzetten van het peil in drie waterlopen. Tijdens het groeiseizoen wordt een flexibel peilbheer gevoerd. De te verwachten effecten voor de landbouw zijn relatief gering, terwijl er een positief effect is voor de natuur in de winter en het voorjaar.
The influence of percolation rate on the weathering rates of silicates in an E horizon of an Umbric Albaqualf
Salm, C. van der; Verstraten, J.M. ; Tiktak, A. - \ 1996
Geoderma 73 (1996)1/2. - ISSN 0016-7061 - p. 83 - 106.
chemische eigenschappen - hydraulisch geleidingsvermogen - infiltratie - fysicochemische eigenschappen - kwel - bodemvorming - chemical properties - hydraulic conductivity - infiltration - physicochemical properties - seepage - soil formation
Weathering rates from laboratory experiments are generally one or two orders of magnitude larger than field weathering rates. To obtain more information on this gap a large undisturbed soil column was percolated with a hydrochloric/sulphuric acid solution at rates of 0.15-0.89 cm/d. The percolate from the soil column was simulated with a dynamic multi-layer model. During the experiment weathering rates decreased upon a reduction in percolation rate. The results could only be simulated by assuming a power-type relationship between weathering rate and percolation rate. Estimated weathering rates for field conditions and pH-stat experiments using the obtained relationship were close to observed values.
Ecohydrology in the Netherlands: principles of an application-driven interdiscipline
Grootjans, A.P. ; Wirdum, G. van; Kemmers, R.H. ; Diggelen, R. van - \ 1996
Acta botanica neerlandica 45 (1996). - ISSN 0044-5983 - p. 491 - 516.
watervoerende lagen - bibliografieën - chemische eigenschappen - ecologie - grondwater - hydrologie - landschap - landschapsecologie - nederland - ecohydrologie - aquifers - bibliographies - chemical properties - ecology - groundwater - hydrology - landscape - landscape ecology - netherlands - ecohydrology
Long-term changes of chemistry and biota in moorland pools in relation to changes in atmospheric deposition
Dam, H. van; Houweling, H. ; Wortelboer, F.G. ; Erisman, J.W. ; Smeulders, S.M. - \ 1996
Wageningen : DLO Institute for Forestry and Nature Research (IBN Research Report 96/6) - 147
meren - reservoirs - plassen - water - waterverontreiniging - waterkwaliteit - eutrofiëring - chemische eigenschappen - neerslag - zuurgraad - zure regen - zwampen - moerassen - wetlands - lakes - ponds - water pollution - water quality - eutrophication - chemical properties - precipitation - acidity - acid rain - swamps - marshes
Oppervlaktewater.
Buuren, M. van; Hoek, I.H.S. ; Jalink, M.H. ; Klijn, F.H. ; Meuleman, A.F.M. ; Molenaar, W. ; Piek, H. - \ 1996
Wageningen : WLO - 121
rivieren - waterlopen - kanalen - water - oppervlaktewater - chemische eigenschappen - hydrologie - watervoorziening - waterbeheer - rivers - streams - canals - surface water - chemical properties - hydrology - water supply - water management
A micromorphological study of pedogenic processes in an evolutionary soil sequence formed in late quaternary rhyolitic tephra deposits, North Island, New Zealand.
Bakker, L. ; Lowe, D.J. ; Jongmans, A.G. - \ 1996
Quaternary International 34-36 (1996). - ISSN 1040-6182 - p. 249 - 261.
andepts - andosols - chemische eigenschappen - nieuw-zeeland - pedologie - fysicochemische eigenschappen - bodemvorming - bodemmicromorfologie - vulkanische gronden - chemical properties - new zealand - pedology - physicochemical properties - soil formation - soil micromorphology - volcanic soils
The influence of time as a soil forming factor was studied on an evolutionary sequence of five soils (1850 radiocarbo years BP-ca. 120,000 BP) developed in rhyolitic tephra deposits in New Zealand. New micromorphological observations were combined with existing macromorphological, chemical, textural, and clay mineralogical analyses to assess the extent of polygenesis in the soils. The younger soils (1850 BP to ca. 22,600 BP) are characterised by initial weathering and little secondary mineral formation. This status is expressed by abundant pumice fragments and fresh, easily weatherable minerals, as well as a low clay content with an isotropic character. Comminution and neoformation are the main pedological processes. The older soils (ca. 120,000 BP) are characterised by a high degree of alteration of primary minerals, little or no pumice fragments, clay illuviation, gleying, and a high clay content (>80%) consisting of a range of crystalline clay minerals including halloysite, gibbsite, kaolinite, and vermiculite, plus crystalline iron oxides. Evidence of polygenesis can be observed in the micromorphology of the older soils: (1) the range of secondary minerals is the result of the integration and succession of soil-forming processes through time; (2) the accumulatory character of the tephra deposits has resulted in stronger weathering of the lower horizons than upper horizons because of continuous pedogenesis. Such polygenesis in the older soils supports the view that the older the soil, the more polygenetic it is likely to be. Copyright
Landscape formation and soil genesis in volcanic parent materials in humid tropical lowlands of Costa Rica
Nieuwenhuyse, A. - \ 1996
Agricultural University. Promotor(en): S.B. Kroonenberg; N. van Breemen. - S.l. : Nieuwenhuyse - ISBN 9789054855446 - 131
bodemvorming - chemische eigenschappen - fysicochemische eigenschappen - vulkanische gronden - andepts - andosols - costa rica - soil formation - chemical properties - physicochemical properties - volcanic soils
<br/>The influence of volcanism on landscape genesis, and formation of soils on volcanic parent material was studied in the Atlantic lowland of Costs Rica. This lowland is a subduction basin of tectonic origin, in which thick alluvial and marine sediments are accumulated. At its southwestern side it is bordered by active volcanoes. The climate of the area is hot and humid throughout the year, with a constant mean air temperature of about 25°C and a welldistributed mean annual rainfall of about 3500 to 5500 mm.<p>Landscape formation was found to be strongly influenced by volcanism. I investigated two particular phenomena: (1) the formation of beach ridges and (2) landscape dynamics in the middle and lower parts of the alluvial plains.<p>The formation of beach ridges along the Caribbean coast, ranging in age between about 100 and 5000 years, appears to be related to discontinuous sand supply by eruptions of the volcanoes which border the study area. This is indicated by small but consistent and statistically significant differences in chemical composition between sediments of individual beach ridges, which cannot be explained by textural differences. The differences are thought to be caused by variations in magma composition of different eruptions in the volcanic hinterland. Si0 <sub><font size="-2">2</font></sub> contents of the ridge sediments vary between about 52% and 58%, other elements show variations corresponding to magmatic differentiation. Petrographically this is expressed in variations in the amount of andesitic rock fragments and pyroxene grains. Chemical composition of beach ridge sediments is similar in composition to the erupted products, in spite of the removal of part of the mobile elements and mixing with weathered sediments.<p>Late Holocene sand deposits fill up former river channels and cover adjacent overbanks in the central fluvial plains of the study area. Two facies types are distinguished. The first is an up to several km long, 3 to 10 m deep, and 10 to 80 m wide coarse sandy channel fill facies, which shows an overall fining upward sequence both in grain size and structure. This facies has a pebbly base, small coarse sandy large troughs in the middle part and sandy trough cross-beds in the upper part. The second facies is a wing-shaped, less than 1.5 m thick, sandy overbank facies which shows small cross-beds and ripple-marks and extends laterally up to 300 m from the channel. The deposits testify to episodic supply of huge amounts of loose material on the upper slopes of the volcanoes that border the area, as a consequence of eruptions. Complete choking of the channel and concomitant shifts of the river course appears to occur only during extreme rainfall events. Of a total surface area of about 300 km <sup><font size="-2">2</font></SUP>, two smaller areas covered with this kind of channel fill deposits related to eruptions of Turrialba volcano about 2000 yrs BP are described, as well as a similar but much younger deposit related to the 1963-1965 eruptions of Irazú volcano. In the distal part of watersheds, thick (up to 1 m or more) crevasse splay sediments appear to be a less voluminous manifestation of fluvial sedimentation triggered by volcanic activity- One of such deposits is described, possibly related to the 1864-1866 eruptions of Turrialba volcano. In the fluvial plain short periods of highly active sedimentation and landscape formation are alternated with longer, rather inactive periods.<p>Soil formation has been studied in relation with time in a Holocene (&lt; 5000 yr) soil chronosequence on sandy, andesitic, ocean beach ridges along the Caribbean coast . All soils are under tropical rainforest. Tropopsamments are present on the 3 younger beach ridges and Hapludands are on the older ones. Drainage conditions change by subsidence from excessively drained in the two youngest soils to imperfectly drained in the two oldest soils. The parent materials of all soils are sands with similar mineralogical composition: andesitic rock fragments, plagioclase, and pyroxene dominate, with minor amounts Of Opaque minerals. None of the parent materials contained>13% (v/v) volcanic glass. It has been found that under these conditions Andisols form within 2000 years. Imperfect drainage caused mottling and accumulation of iron-coatings, as well as the formation of a thin O- horizon in the two oldest profiles. The increase in fine material and the accumulation of organic matter cause an increase of CEC and andic properties, and a decrease in bulk density and pH with soil age. Depth of biological influence increases with soil age, but soil faunal activity is hampered in the oldest three profiles, probably by imperfect drainage. Due to extreme leaching, the sum of exchangeable bases is less than 2 cmol+.kg <sup><font size="-2">-1</font></SUP>in the B-horizons of the older soils, notwithstanding the presence of a considerable amount of weatherable primary minerals.<p>Using micromorphological, mineralogical, and chemical analyses, weathering and neoformation of minerals was investigated in the same chronosequence. Weathering and neoformation of minerals with increasing soil age is characterized by: (i) increasing pellicular and linear alteration of sand grains and (ii) decrease of the sand fraction and concomitant increase of finer material. Andesitic rock fragments weather more rapidly than plagioclase and pyroxene mineral grains. The alteration rates of the latter two are similar. Clay content in the about 2000-yr-old soil is several times higher than in soils developed on rhyolitic parent materials of similar age in New Zealand. Formation of allophane with Si/Al ratios ranging from 1.9 to 3.8 takes places mainly in the B horizons. Aluminium-humus complexes, allophane, and Al oxides and hydroxides are mainly formed in the A horizons. Small amounts of gibbsite were noticed in soils older than 2000 yr. Small amounts of 2:1 and 1:1 clay minerals present in the clay fraction of all soils are thought to be inherited from the parent material, which contained sand-sized bodies of clay and andesitic rock fragments with clay pseudomorphs, both consisting of 2:1 and 1:1 clay minerals.<p>Furthermore, an attempt was made to quantify aspects of soil formation in eight soil profiles developed on volcanic parent material in the area. Assuming Ti to be immobile, gains and losses of major elements in were calculated from total element contents. Initially soil formation (0 to 0.5 ka) in Tropopsamments involves dilation of the sandy deposits by incorporation of organic matter and formation of structure and biopores, without detectable gains or losses of elements. In 2 to 5 ka old sandy Hapludands, primary minerals are still abundant, but up to 20% of the mineral soil consists of X-ray amorphous materials. Dilation continues and losses of Mg, Ca, Na and K, and to a lesser degree Si, have become measurable. In a &lt; 18 ka old, stony Melanudand primary minerals and, especially, volcanic glass, become depleted in the fine-earth fraction. A mixture of short-range order material, metal-humus complexes, gibbsite and kaolin minerals dominate in the A horizon, while gibbsite, halloysite, and short- range order material are the most important secondary minerals at greater depths. Dilation of the soil mass prevails in the A horizon, while collapse has occurred in the B horizon. Considerable amounts of mobile elements are lost: 50 to 85% of Si, Mg, Ca, Na, and K have been leached from the soil profile. The strongly collapsed Haploperox,>50 to 450 ka old, thought to have formed from Andisols, are devoid of primary minerals (except opaques) in the upper meters, and are dominated by gibbsite, kaolin minerals and iron (hydr)oxides. Under the prevailing environmental conditions, weathering and neoformation of primary volcanic minerals lead to almost complete losses of basic cations, probably in a time period between 20 and 50 ka. Si and P mineral reserves are depleted considerably, but part is still present after such long time periods.
An economic analysis of tradeable emission permits for sulphur dioxide emissions in Europe
Kruitwagen, S. - \ 1996
Agricultural University. Promotor(en): H. Folmer; L. Hordijk. - S.l. : Kruitwagen - ISBN 9789054855842 - 235
neerslag - chemische eigenschappen - zuurgraad - zure regen - atmosfeer - milieu - overheidsbeleid - milieubeleid - milieuwetgeving - luchtverontreiniging - bodemverontreiniging - waterverontreiniging - lucht - hygiëne - economisch beleid - instrumenten (meters) - vergunningen - zwaveldioxide - kwaliteit - conservering - landen van de europese unie - maatregelen - precipitation - chemical properties - acidity - acid rain - atmosphere - environment - government policy - environmental policy - environmental legislation - air pollution - soil pollution - water pollution - air - hygiene - economic policy - instruments - permits - sulfur dioxide - quality - conservation - european union countries - measures
<strong>7.1 Introduction</strong><br/>This study has examined the question of whether a system of tradeable emission permits can contribute to a cost-effective reduction of SO <sub><font size="-2">2</font></sub> emissions in Europe, taking into account prespecified deposition targets and what sort of system it should be. To deal with this question three research topics have been examined.<br/>(I) What are the main economic aspects of a European acid rain policy?<br/>(II) What are the advantages and the disadvantages of using a system of tradeable permits to implement a European acid rain policy?<br/>(III) What should a system of tradeable emission permits for a non-uniformly mixing pollutant look like in order to take deposition targets into account?<p>This chapter summarizes and presents the conclusions of this research. First 1 present the conclusion on the efficacy of the different integrated assessment models in analysing the effects of emission reduction. I then summarize the conclusions on guided bilateral permit trading. Finally, I make several suggestions for further research.<p><strong>7.2 Economic theory of pollution control</strong><br/>In this research I have followed the ecological approach to pollution control. This approach does not aim at optimal pollution control levels where marginal abatement costs equal marginal benefits. Marginal benefits are usually too difficult to determine. Instead it aims at cost-effective abatement of pollutants to reach prespecified enviromnental targets. Since acid rain is an international environmental problem, cost- effective abatement needs to be considered in an international context. To achieve cost-effective international abatement it is necessary to have cooperation among countries. Although full cooperation results in minimized total costs for the cooperating countries, individual countries may, however, not act accordingly. This has been explained by the existence of the prisoner's dilemma. However, the assumptions underlying the prisoner's dilemma do not always hold in reality, and in the real world, countries do have some incentives to cooperate. Moreover, side payments can be introduced to stimulate countries to participate in cooperative abatement strategies.<p>Another issue I discussed is which policy instruments can be used to implement pollution control policy. A main distinction can be made between economic and non- economic instruments (regulation). A main advantage of economic instruments is their cost-effective character because, unlike regulation, economic instruments result in minimum control costs. Moreover, they allow more flexibility to the polluters and provide a continuous incentive for developing and adapting new control technologies. This thesis has elaborated on the use of tradeable emission permits.<p><strong>7.3 Tradeable permits for non-uniformly mixing pollutants</strong><br/>Environmental degradation by non-uniformly mixing pollutants depends not only on the amount of emission, but also on the location of that emission. Accordingly, the environmental aim I followed in this study was not to reach an emission target, but rather to reach deposition targets. This has main consequences for using a system of tradeable emission permits as this system, in principle, only regulates emissions. It does not take the resulting depositions into account. The implications of permit trading for non-uniformly mixing pollutants have been illustrated and the alternatives for taking emission location into account in permit trading, that were put forward in the literature were discussed in Chapter 3.<p>It cannot be concluded in general that emission permits are a suitable instrument for controlling non-uniformly mixing pollutants. The use of emission permits results in a cost-minimum reduction of emissions, but the enviromnental implications of this emission reduction are uncertain, as deposition may be unacceptably large at some locations. To what extent the resulting cost-effective emission allocation deviates from the cost-effective deposition allocation depends on the source-receptor relationships and the marginal control costs of controlling the sources. In the USA, however, tradeable emission permits are actually used for the non-uniformly mixing pollutant SO <sub><font size="-2">2</font></sub> . Nevertheless, one should be aware that this emission trading does not focus on reaching a deposition target, but is only emission oriented. Environmental targets are taken care of by State Implementation Plans in the USA.<p>Deposition permits are an obvious alternative to emission permits for taking emission location into account. Theoretically, the use of tradeable deposition permits results in a cost-effective allocation that meets deposition targets. According to this system, sources have to own the appropriate number of deposition permits for each receptor affected. In this way authorities can control deposition targets. However, a disadvantage of this system is that it may result in an increase in emissions, which is politically delicate. Another argument against this system is the trading complexity that occurs because sources have to operate simultaneously in many different markets.<p>Since the use of both emission and deposition permits is not considered to be a very suitable instrument, several alternatives permit systems for non-uniformly mixing pollutants have been proposed in the literature. Relatively simple alternatives are permit trading within zones and the 'worst case' approach, but unfortunately, these systems do not guarantee the non-violation of deposition targets.<p>A promising permit trading system that does not violate deposition targets seems to be a more advanced one where the trading is subject to rules. Three variants are known: the pollution offset, the non-degradation offset and the modified pollution offset. All systems guarantee non-violation of deposition targets. The constraints on emissions and on deposition targets, however, differ between these systems. The pollution offset offers the largest trade opportunities, but allows for an increase in emissions. The non-degradation offset and the modified pollution offset are more restricting and consequently result in higher abatement costs. Which of the two has the lower cost cannot be shown on theoretical grounds.<p>In judging permit trading systems, special attention has to be paid to the nature of the trading process. Although many studies implicitly assume a simultaneous trading process, it seems more reasonable to consider permit trading as a bilateral and sequential process. Combining permit trading subject to rules with the bilateral and sequential trading concept sheds new light on the cost-effectiveness of these permit trading systems. Empirical studies indicate that bilateral permit trading applying offset rules do not result in cost-effective abatement. However, bilateral and sequential trading has only been recently applied to studies on permit trading, and has been examined further in this study. A main conclusion is that permit trading for non-uniformly mixing pollutants has to be restricted in some way if deposition targets are to be taken into account. What is needed are restrictions that result in non-violation of deposition targets, and at the same time, do not hamper the attainment of the cost-effective allocation.<p><strong>7.4 Integrated assessment models</strong><br/>Integrated assessment models can be used for quantifying the consequences of abatement allocations. These models provide a scientific basis for evaluating alternative abatement allocations and are therefore a useful tool in policy making. Three integrated assessment models are available for Europe : (i) the Regional Acidification INformation and Simulation model (RAINS); (ii) the Abatement Strategies Assessment Model (ASAM) and (iii) the Coordinated Abatement Strategy Model (CASM). Integrated assessment models provide information on emissions, abatement costs, the atmospheric transport of emissions and the environmental effects of alternative abatement strategies. Since accurate monetarization of enviromnental damage is very difficult and complex in practice, the environmental damage is expressed in physical terms. For acidification, the environmental damage is expressed in exceedance of critical loads. Given these targets, a cost-effective emission abatement policy can be found. This makes these models very useful for policy analysis.<p>Among the European integrated assessment models, the RAINS model is the most complete and extensive. Although the RAINS model, the ASAM and the CASM are roughly similar, they diverge on various points as well. One difference is the number of acidifying compounds they take into account. Other differences are the optimization options that are implemented and the accuracy of the emission location. Finally, the data sources used differ in some submodels. The main benefit of the ASAM is its accuracy on emission locations and the resulting atmospheric transport. However, because of lack of data for this purpose, the intended accuracy is only partial. Model results show no significant differences caused by the grid to grid approach used. A serious drawback of this model is the lack of clarity of the procedure needed to derive the so called Best Economic Environmental Pathway. The CASM is attractive because of its large number of optimization criteria. However, since policy aims at reaching certain deposition targets, optimization criteria to minimize environmental damage, given a budget constraint are not actually very useful for policy purposes. Comparison of the CASM and the RAINS model shows that the model results are broadly in line with each other.<p>There are two reasons for the current status of acceptance of the RAINS model. First, the model is the most completely integrated assessment model for acidification. The alternative integrated assessment models, the CASM and the ASAM do not substantially improve the RAINS model. Second, RAINS was developed by scientists of various disciplines at an international "East-West" institute. This aspect mainly played a role in the acceptance of RAINS in international policy making (Hordijk, 1991, 1995). Acid rain models have substantially increased knowledge of the acid rain problem and have provided useful information for assisting and improving policy making. In this research I used the RAINS model for calculations. The reasons for this choice were those given above: (i) the model is the most complete one for acidification and (ii) the model is widely accepted and was used in the international negotiations on the Second Sulphur Protocol.<p><strong>7.5 Guided bilateral trade</strong><strong></strong><p><strong>7.5.1 Theory</strong><br/>Research has shown that in case of non-uniformly mixing pollutants, permit trading has to be constrained if a cost-effective emission allocation is to be attained. It has been argued that if permit trading is constrained, it is necessary to consider permit trading as a bilateral process. In Chapter 5 I developed a new system for bilateral permit trading describing it as guided bilateral trade. The aim of this system is to provide large trade opportunities while at the same time preventing the violation of deposition targets. However, it is not necessary to require that every trade transaction meets the deposition targets. A subsequent trade transaction might compensate for the deposition exceedance at a receptor brought about by a previous trade transaction. To be able to take care of the deposition targets, the guided bilateral trade system restricts trading by a trade vector which indicates the number of permits sources are allowed to sell or buy.<p>Guided bilateral permit trading achieves a cost-effective allocation if all trade transactions that are in accordance with the trade vector are profitable. A drawback of guided bilateral permit trading is that trade transactions are not necessarily profitable. Whether this is so depends on the source-receptor relationships, the abatement cost functions, the deposition targets and the initial permit distribution. To reach the deposition targets ultimately, non-profitable trade transactions need to be compensated in some way. Before trade transactions can be guided to the costeffective emission allocation, this allocation has to be known. Therefore full information is required by the trade institution in order to establish the trade vector. Unfortunately, this cancels out one of the characteristics of tradeable permits, namely that full information is not needed. Knowledge on the costeffective emission allocation by policy makers might cause the guided bilateral permit system to become unnecessary. However, knowing this allocation does not by definition imply that it will be agreed upon at once, as can be seen from the Second Sulphur Protocol. In that case, a suitable instrument for achieving further cost savings is a system of guided bilateral trade.<p>The term guided bilateral trade indicates that the permit market as such is not able to generate the desired outcome. The trade process has to be guided by a trade institution that takes care of the number of traded permits. However, any trading system that takes deposition targets into account will need some kind of control. The main advantage of the guided bilateral trade system is that the costeffective emission abatement allocation can be achieved if all trade transactions are profitable, or, if not, when non profitable transactions are subsidized. In the past, achieving the cost- effective allocation was thought to be possible by means of a simultaneous trade process. However, as I indicated in section 5.3, the practical functioning of such a trade system is a black box. This box can be opened by means of the system of guided bilateral trade.<br/>7.5.2 Simulation results<p>To examine to what extent the guided bilateral trade system results in a costeffective reduction of S02 emissions in Europe, taking into account deposition targets, I used the RAINS model to simulate guided bilateral permit trading among European countries for SO <sub><font size="-2">2</font></sub> emissions. In calculating the cost-effective emission allocation, emission is measured at national level. Accordingly, guided bilateral permit trading only allocates emission reduction between countries. The way in which countries meet their emission reduction is a next step. For the sake of completeness it should be noted that the European abatement allocation is only cost-effective if all individual countries also reduce their national emissions in a cost minimum way. I simulated guided bilateral permit trading for three cases. In the policy oriented Base Case, permit trading aimed at the cost-effective emission allocation, given the Current Reduction Plans of the European countries. In variant 1 the restriction of Current Reduction Plans was released. Variant 2 examined guided bilateral permit trading, starting from the SO <sub><font size="-2">2</font></sub> Protocol.<p>The simulation results indicated that permit trading steers the trade process towards the cost-effective allocation of emission abatement, but the cost-effective allocation of emission abatement will not be fully reached by profitable trade transactions. In all three cases, the profit generated by guided bilateral permit trading was substantial. In the Base Case and in variant 1, the cost saying of permit trading amounted to 13.5% of the total abatement costs. From a policy point of view, variant 2 is very interesting since it draws heavily on the actual situation in Europe. The simulation result of Variant 2 indicated that guided bilateral permit trading, starting from the emission allocation in the Second SO <sub><font size="-2">2</font></sub> Protocol, results is a cost saving of 7.8% of the total abatement costs. Given this result, we may conclude that, compared to the SO <sub><font size="-2">2</font></sub> Protocol, some cost-effective improvement is possible by guided bilateral permit trading. However, it should be noted that the simulation results excluded transaction costs. Therefore, the indicated cost savings can be regarded as the upper limit of possible savings.<p>The simulation results indicated that the trade sequence influenced the generated profit. However, the simulations showed that the impact of trade sequences on the profit level was small. This suggests that a trade coordinating institute does not have to play an active role in the matching of trade partners, but only has to control whether countries trade according to the trade vector.<p>Having discussed the main aspects of this study I now want to turn to the third research question. By developing the guided bilateral permit trading system I have shown how a permit trading system for non-uniformly mixing pollutants could be formulated that takes deposition targets into account. The main drawback of this system is that full information on the cost-effective allocation is needed by the environmental authorities if such a trading system is to be successfully implemented. But, it should also be realized that in the current practice this information has already been used: in the negotiations on the Second Sulphur Protocol the information on the cost-effective emission allocation provided by the RAINS model served as a guideline for the agreed emissions reduction. Since countries agreed upon the emission reductions in the Second Sulphur Protocol, they might agree on a permit trading system that is based on the same information.<p><strong>7.6 Guided bilateral trade revisited</strong><br/>In this study I have been extensively illustrated that aiming at deposition targets for acidification while minimizing abatement costs is a complex matter. It depends on three factors: the source receptor relationships, the deposition targets and the differences in marginal abatement costs. Obviously, a policy instrument that is designed to generate a cost-effective abatement allocation needs to deal with this complexity. After having analysed the system of guided bilateral trade for SO <sub><font size="-2">2</font></sub> emissions in Europe thoroughly, the final question that has to be looked at is whether this system would be suitable for implementation in practice and how it could be introduced. This question is discussed in this section, paying attention to cost effectiveness, innovation, international agreements, implementation costs, distributional effects and practical implementation.<p>The system of guided bilateral permit trading succeeds in reaching the <em>cost-effective</em> abatement allocation if all allowed trade transactions are profitable. If not, the cost- effective allocation will only be fully reached if the trade transactions needed to reach this cost-effective allocation are subsidized. This will be difficult since it is necessary to prune away profits from profitable trades to generate funds for subsidizing. However, the simulation results of guided bilateral permit trading indicate that the violation of deposition targets is only very moderate if the costeffective allocation is not fully reached by guided bilateral permit trading. Therefore it can be stated that guided bilateral permit trading is sufficient for the cost-effectiveness criterion. Arguments generally favouring the use of tradeable emission permits are that the use of permits provides a continuous incentive to search for technology <em>innovation</em> and provides flexibility to polluters in the way they want to comply with the environmental targets. Guided bilateral trade provides this incentive and flexibility as well.<p>An important aspect in judging the suitability of guided bilateral permit trading is the conformity with <em>international agreements.</em> In this thesis 1 have shown that given the Second Sulphur Protocol, guided bilateral permit trading can improve the cost- effectiveness of emission abatement. Whether a system of guided bilateral permit trading will really be successful will largely depend on the willingness of the European countries to accept the specified trade rules and the initial distribution of permits. A disadvantage for negotiating countries may be that emission permits, by definition, put a price on pollution that was previously free. To make permits acceptable, countries first have to receive permits for free. In this thesis it was suggested that the agreed emission levels from the Second Sulphur Protocol could serve as a guideline for the initial distribution of permits, since countries have already committed themselves to these amounts. In fact, given the current sulphur protocol, the guided bilateral permit trading system provides a 'recipe' for reaching the cost- effective sulphur dioxide allocation in Europe. Since the sulphur protocol is an agreement among national governments, permit trading among these governments is an obvious succession. However, alternatively, a system could be implemented in which permit trading could take place among firms (see section 7.7).<p>The <em>costs of implementation</em> of a guided bilateral permit trading system have not been studied in this research and it is therefore difficult to judge the system on this criterion. However, compared to the current international practice of negotiations, there seems to be no indication so far that the costs of this trading system will be substantially higher. Neither the <em>distributional aspects</em> of guided bilateral permit trading have been dealt with extensively. In general, no country will be worse off with permit trading, since a country will only trade permits if this results in a profit, resulting in a Pareto improvement. A country selling permits will only sell permits if the permit price exceeds the marginal abatement costs, and a country will only buy permits if this is cheaper than emission abatement. So, in so far as the abatement costs of countries change as a result of permit trading, this change is always compensated by the buying or selling of permits. Therefore, guided bilateral permit trading will only result in very moderate distributional effects.<p>The most obvious way for <em>practical implementation</em> of guided bilateral permit trading is to extend the Second Sulphur Protocol with a guided bilateral permit trading scheme in an additional annex, in accordance with annex II in which the current committed emission reductions are stated. Currently, countries are obliged to report the annual levels of sulphur emissions to the Executive Body of the Convention each year. Likewise, countries could be obliged to report their trade transactions annually. I suggest that it is better to include a trade scheme in the protocol rather than the trade vector, since a trade scheme as presented in Table 6.15 or 6.16 results in the largest cost savings. Furthermore, by presenting a trade scheme, countries do not have to search for their trading partner. This form of implementation does not require the establishment of a new agency since it fits into the current international negotiation arrangement on acidification, through the Convention under the Economic Commission for Europe of the United Nations.<p>In this section I have indicated that guided bilateral permit trading principally offers a suitable supplement to the sulphur protocol for reaching a cost-effective emission allocation. I have also indicated how such a trading system could be implemented. Remembering that the simulation results showed that guided bilateral permit trading may generate a cost saving of 143 million DM, this system can be taken as a suitable policy instrument for reducing sulphur dioxide emissions. Whether it can really be successfully implemented largely depends on the political willingness of countries to accept such a trading scheme.<p><strong>7.7 Suggestions for further research</strong><br/>Many aspects on tradeable emission permits have been examined in the literature. In this thesis I have emphasized the application of such permits to non-uniformly mixing pollutants for which a bilateral and sequential permit trading has been developed. This research could be extended to include topics such as banking of permits or market power. Additional suggestions for further research include (i) the aggregation in permit trading, (ii) the enlargement of permit trading to total acidification and its relation to other environmental problems, (iii) permit trading in relation to other environmental problems ensuing from common sources and (iv) the implementation of guided bilateral permit trading where there is no protocol.<p>(i) In this study I have assumed permit trading takes place among national governments. One justification for this is that a permit trading system has a fair chance of being accepted if it is close to the current multiparty negotiations that assign targets to nations, as in the sulphur protocols. An alternative would be that emission permits be distributed to and traded by firms. Arguments in favour of this are that national governments lack experience and lack knowledge about operations and compliance options at the firm level. The question is what guided bilateral permit trading would look like if trading took place among firms. Although the general methodology of guided bilateral permit trading needs no modification, if trading is taking place among firms rather than among countries, its implementation requires additional research. To simulate permit trading among firms, additional data are needed. The source receptor matrix has to be adapted since it is the location of firms that matters now. The source receptor matrix has to link the firm's emissions to deposition, Moreover, abatement costs have to be specified at the firm level. The current RAINS-Europe model does not contain these necessary data and refinements. However, the RAINS-Asia model, a policyoriented model which provides a framework for integrated assessment of acid deposition in Asia, does already provide an analysis for large point sources. In this model, the emissions of 355 large point sources are linked to deposition at 1°x 1° grid cells (Foell et al., 1995).<p>Alternatively, permit trading between firms could be analysed by a 'two-stage method'. This method, which needs no modification of the source receptor matrix, consists of first selecting two trading countries and next of selecting the firms with the lowest and the highest marginal control costs within these countries. Obviously, the firm with the lowest marginal costs is selected for the country selling permits and the firm with the highest marginal costs for the country buying permits. The next trade would be between the firms with the second highest and the second lowest costs, and so on.<p>(ii) Acidification is not only caused by sulphur dioxide emission, but also by nitrogen oxides and ammonia. Instead of analysing trade in of sulphur permits, as I have done in this thesis, it would be interesting to study the opportunities for the use of tradeable permits for total acidification. This multipollutant approach is in accordance with the ongoing negotiations on a following protocol on acidification. However, it requires additional research, including the following topics. Firstly, the three pollutants contribute in a different way to acidity. This would lead to possible substitution of emission reduction. Further, spatial patterns of emission and deposition differ, and abatement-cost functions show differences. These differences imply that permit trading for total acidification will be complex, but considering all acidifying emissions simultaneously may provide additional cost savings. An interesting topic to analyse in this context is how to allocate the emission reductions of sulphur dioxide and nitrogen oxides as the latter contribute both to acidification and to tropospheric ozone. The role of nitrogen oxides in acidification has been discussed in Chapter 1. Tropospheric ozone is formed by complex chemical reactions of volatile hydrocarbons (VOC) and nitrogen oxides. The ratio of VOC and NO <sub><font size="-2">x</font></sub> , and not merely their total amounts, is important for ozone formation. This implies that when the ratio of VOC to NO <sub><font size="-2">x</font></sub> is very small, reduction of NO <sub><font size="-2">x</font></sub> , can actually increase ozone formation. In general, the abatement of nitrogen oxide is more expensive than the abatement of sulphur dioxide. This implies that a shift from nitrogen oxides to sulphur dioxide emission reduction would result in cost savings. However, as nitrogen oxides contribute to tropospheric ozone, preventing high ozone concentrations might, in some cases, prohibit the reduction of nitrogen oxides. An additional restriction on NO <sub><font size="-2">x</font></sub> emissions would be needed to take this into account in a permit trading system .<p>(iii) A third extension of guided bilateral permit trading for sulphur dioxide emission would be to link sulphur dioxide emission to climatic change. The rationale for this is that both problems have a common source, that is, energy use. In the RAINS model for Europe which was used for this study, only end-of-pipe technologies are available for reducing emissions. However, changes in energy use may be of benefit to both acidification and climatic change. To analyse the effect of changes in energy use for sulphur dioxide emissions the RAINS model should be extended with an accurate energy scenario module. The RAINS-Asia model is already equipped to generate energy scenarios. The so called energy scenario generator in this model estimates energy consumption contributing to SO <sub><font size="-2">2</font></sub> emissions (Foell et al., 1995).<p>(iv) A final topic for further research is how to implement a system of guided bilateral permit trading if a protocol had not yet been signed. Given an agreed initial permit allocation and given the restriction of the trade vector, it would be obvious to provide the opportunity to trade emission permits. Countries will have a strong incentive to trading since this is beneficial in terms of costs. If it appeared that countries would not trade, this could be an indication that transaction costs are too high. If transactions costs exceeded the indicated cost savings, permit trading would not take place, and countries would comply with the emission reduction without trading.<p>It has become clear that research on tradeable emission permits for sulphur dioxide emissions is an interesting topic that needs further investigation. Extending the research by the suggested options may provide new insights into how to achieve emission reductions at minimum abatement costs. Especially growing economies, such as those in Asia and Latin America, that will suffer from sulphur dioxide emissions and deposition in the near future, can benefit from a better insight into tradeable emission permits for reaching cost-effective reductions.
Modelling of soil acidity and nitrogen availability in natural ecosystems in response to changes in acid deposition and hydrology
Kros, J. ; Reinds, G.J. ; Vries, W. de - \ 1995
Wageningen : SC-DLO (Report / DLO Winand Staring Centre 95) - 90
bodem ph - bodemaciditeit - bodem - stikstof - plantengemeenschappen - vegetatie - onderzoek - ecologie - hydrologie - neerslag - chemische eigenschappen - zuurgraad - zure regen - modellen - ecohydrologie - soil ph - soil acidity - soil - nitrogen - plant communities - vegetation - research - ecology - hydrology - precipitation - chemical properties - acidity - acid rain - models - ecohydrology
Changes in vegetation are often caused by changes in abiotic site factors. The SMART2 model has been developed to evaluate the effects of changes in ion inputs by atmospheric deposition and seepage on these site factors. Linkage with the Multiple Stress Model for Vegetation (MOVE) enables evaluation of the effects on the occurrence probability of vegetation species in response to deposition and seepage scenarios. Combinations of two deposition and two seepage scenarios were evaluated with SMART2. Results focused on pH, nitrogen availability and base saturation. Effects of changes in pH on the occurrence probability of forest understorey in a nutrient-poor deciduous forest were evaluated with MOVE.
Scenario studies on soil acidification at different spatial scales
Vries, W. de; Kros, J. ; Groenenberg, J.E. ; Reinds, G.J. ; Salm, C. van der; Posch, M. - \ 1995
In: Scenario studies for the rural environment : selected and edited proceedings of the symposium scenario studies for the rural environment, Wageningen, The Netherlands, 12 - 15 September 1994 / Schoute, J.T.H., Finke, P.A., Veeneklaas, F.R., - p. 169 - 188.
zure gronden - kattekleigronden - neerslag - chemische eigenschappen - zuurgraad - zure regen - modellen - onderzoek - acid soils - acid sulfate soils - precipitation - chemical properties - acidity - acid rain - models - research
Three dynamic soil acidification models have been developed for application on local, national and continental (European) scales, namely NUCSAM, RESAM and SMART. This paper gives an overview of results of various model validation and scenario studies for the effects of SOx, NOx and NHx deposition on soils. Furthermore, the various strong and weak points of the models are evaluated in terms of uncertainties in model predictions, the use of the models in acidification abatement policies, and the limitations and possibilities of using the models in other scenario studies, such as changes in land use, hydrology and heavy-metal deposition.
Humus- en bodemprofielen in natte schraalgraslanden; resultaten van een bodemkundig onderzoek in 13 referentiegebieden voor het onderzoek naar Effectgerichte Maatregelen tegen verzuring (EGM)
Delft, S.P.J. van - \ 1995
Wageningen : DLO-Staring Centrum - 166
organische verbindingen - bodem - bodemchemie - bodemkarteringen - graslanden - natuurgebieden - chemische eigenschappen - zuurgraad - zure regen - nederland - organic compounds - soil - soil chemistry - soil surveys - grasslands - natural areas - chemical properties - acidity - acid rain - netherlands
In dertien referentiegebieden voor het onderzoek naar effectgerichte maatregelen tegen verzuring in natte schraalgraslanden zijn profielbeschrijvingen gemaakt. De referentiegebieden liggen in beekdalen, laagveengebieden en natte duinvalleien verspreidover Nederland. Er zijn 160 boringen verricht tot maximaal 3 m. Speciale aandacht is besteed aan het humusprofiel, dat indicatief kan zijn voor de mate van verzuring en verdroging van de bodem. De beekdalen, in de pleistocene dekzandlandschappen, zijn deels met venige of moerige afzettingen opgevuld. Hier komen mull- en moderhumusvormen voor. In de laagveengebieden komen alleen semi-terrestrische humusvormen voor, in de duinvalleien moder- en mullhumusvormen.
Evaluatie van de ecohydrologische systeembeschrijving van de Gelderse Poort
Jansen, P.C. ; Kemmers, R.H. - \ 1995
Wageningen : DLO-Staring Centrum - 73
kanalen - chemische eigenschappen - ecologie - hydrologie - rivieren - kwel - waterlopen - oppervlaktewater - water - nederland - ecohydrologie - gelderland - gelderse poort - canals - chemical properties - ecology - hydrology - rivers - seepage - streams - surface water - netherlands - ecohydrology
Voor het natuurontwikkelingsproject De Gelderse Poort wordt een hydrologisch deelonderzoek uitgevoerd om de potenties van het gebied aan te geven, om een analyse van het hydrologische systeem te ondersteunen, en om effecten van ingrepen te volgen. In raaien zijn de waterstanden en de grond- en oppervlaktewaterkwaliteit gemeten. Ook is het elektrisch geleidingsvermogen geonventariseerd. De analyseresultaten zijn gerelateerd aan referenties voor diep grondwater, neerslagwater en verontreinigd rivierwater. Vervolgens zijn grondwaterstroming, infiltratie- en kwelgebieden en de invloed van de rivieren aangegeven. De resultaten worden getoetst aan het hydrologische systeem dat in het voorgaande jaar is beschreven aan de hand van de waterkwaliteitsmetingen.
Evaluation of estimation methods and base data uncertainties for critical loads of acid deposition in Japan
Shindo, J. ; Bregt, A.K. ; Hakamata, T. - \ 1995
Water Air and Soil Pollution 85 (1995)4. - ISSN 0049-6979 - p. 2571 - 2576.
precipitation - chemical properties - acidity - acid rain - statistics - japan
A simplified steady-state mass balance model for estimating critical loads was applied to a test area in Japan to evaluate its applicability. Three criteria for acidification limits were used. Mean values and spatial distribution patterns of critical load values calculated by these criteria differed greatly. To evaluate the uncertainty of the base cation weathering rate used for calculating critical loads, ion content and particle size distribution were measured for the soils collected from the test area. The base cation weathering rate was estimated with the PROFILE model based on these measurements. The base cation weathering rates estimated from surface geology were adequate as mean values, but had uncertainties of 50% of the averages.
Uncertainties in long-term predictions of forest soil acidification due to neglecting seasonal variability
Kros, J. ; Groenenberg, J.E. ; Vries, W. de; Salm, C. van der - \ 1995
Water Air and Soil Pollution 79 (1995)1/4. - ISSN 0049-6979 - p. 353 - 375.
bosschade - zure regen - zure gronden - kattekleigronden - neerslag - chemische eigenschappen - zuurgraad - modellen - onderzoek - forest damage - acid rain - acid soils - acid sulfate soils - precipitation - chemical properties - acidity - models - research
Soil and soil solution response simulated with a site-scale soil acidification model (NUCSAM) was compared with results obtained by a regional soil acidification model (RESAM). Uncertainties due to neglecting seasonal variability in long-term predictions were investigated by comparing long-term RESAM and NUCSAM simulations. Although both the seasonal and the interannual variations in soil solution parameters were large, the trend in soil solution parameters of RESAM and NUCSAM corresponded quite well. Generally, it appeared that the uncertainty due to time resolution in long-term predictions was relatively small.
Application of soil acidification models with different degrees of process description (SMART, RESAM and NUCSAM) on an intensively monitored spruce site
Salm, C. van der; Kros, J. ; Groenenberg, J.E. ; Vries, W. de; Reinds, G.J. - \ 1995
In: Solute modelling in catchment systems / Trudgill, S.T., - p. 327 - 346.
zure gronden - kattekleigronden - bosbouw - neerslag - zure regen - zure depositie - chemische eigenschappen - zuurgraad - modellen - onderzoek - acid soils - acid sulfate soils - forestry - precipitation - acid rain - acid deposition - chemical properties - acidity - models - research
A one-layer (SMART) and a multi-layer (RESAM) soil acidification model with temporal resolutions of one year and a multi-layer model with a resolution of one day (NUCSAM) were applied to an intensively monitored spruce site in Solling, Germany. The major aim was to study the influence of model simplifications and reduction of temporal and vertical resolutions on the simulation of soil solution concentrations. Results showed that all the models were able to simulate most of the concentrations reasonably during the examined period (1973-1989). However, the one-layer model, SMART, had difficulties in simulating strong changes in soil solution concentrations owing to a lower retardation in the soil system.
The role of earthworms in the formation of sandy surface soils in a tropical forest in Ivory Coast.
Nooren, C.A.M. ; Breemen, N. van; Stoorvogel, J.J. ; Jongmans, A.G. - \ 1995
Geoderma 65 (1995). - ISSN 0016-7061 - p. 135 - 148.
chemische eigenschappen - ivoorkust - aardwormen - fysicochemische eigenschappen - zandgronden - bodemvorming - chemical properties - cote d'ivoire - earthworms - physicochemical properties - sandy soils - soil formation
Prevalence of Campylobacter in Dutch sewage purification plants
Koenraad, P.M.F.J. - \ 1995
Agricultural University. Promotor(en): F.M. Rombouts; S.H.W. Notermans. - S.l. : S.n. - ISBN 9789054854128 - 149
afvalverwerking - rioolwater - afvalwater - samenstelling - chemische eigenschappen - fysische eigenschappen - campylobacter - microbiologie - afvalwaterbehandeling - zuiveringsinstallaties - waste treatment - sewage - waste water - composition - chemical properties - physical properties - microbiology - waste water treatment - purification plants
<p><em>Campylobacter</em> bacteria are an important cause of bacterial gastro-enteritis in man. Although food of animal origin is the main source of human infection, a casecontrol study in the United States of America showed that 8% of all campylobacteriosis cases could be attributed to consumption of contaminated surface water. In this thesis the prevalence of <em>Campylobacter</em> in sewage purification plants was investigated in order to obtain more information on the survival of this pathogen in aquatic environments. A survey carried out on three municipal plants showed that sewage and surface waters are frequently contaminated with <em>Campylobacter.</em> The contamination of sewage was higher when meat-processing industries were present in the drainage area of these plants. Indeed, drain water of a poultry abattoir contained high numbers of <em>Campylobacter</em> . It is clear that other sources contribute far lower numbers to sewage. Furthermore, the aquatic <em>Campylobacter</em> isolates were more resistant to quinolones and to ampicillin when a meat-processing industry was draining its waste on the sewerage.<p>The purification process reduced the numbers of <em>Campylobacter</em> , but this pathogen was not eliminated completely. The prevalence and reduction were not correlated with enviromnental parameters, such as water temperature and oxygen pressure.<p>The phenomenon of the transformation of spiral <em>Campylobacter</em> cells to coccoid cells was also investigated. Determination of several physiological parameters indicated that the contribution of the nonculturable, coccoid <em>Campylobacter</em> cells is to infection routes probably negligible.<p>Considering the observed occurrence of <em>Campylobacter</em> in surface waters, in the context of the reported dose-response model for this pathogen, it can be concluded that the role of surface waters in the epidemiology of <em>Campylobacter</em> may be underestimated.
Impacts of acid deposition on concentrations and fluxes of solutes in acid sandy forest soils in the Netherlands.
Vries, W. de; Grinsven, J.J.M. van; Breemen, N. van; Leeters, E.E.J.M. ; Jansen, P.C. - \ 1995
Geoderma 67 (1995)1. - ISSN 0016-7061 - p. 17 - 43.
neerslag - chemische eigenschappen - zuurgraad - zure regen - bodem - stikstof - zwavel - aluminium - bodem pH - bodemaciditeit - Nederland - precipitation - chemical properties - acidity - acid rain - soil - nitrogen - sulfur - soil pH - soil acidity - Netherlands
This article summarizes the most important impacts of acid atmospheric deposition on the soil solution chemistry of acid sandy forest soils in the Netherlands, by comparing and interpreting data from soil solution monitoring studies (18 stands) and a national soil solution survey (150 stands). Important conclusions are: forest soils are invariably saturated with sulphate (leaching equals deposition); there is generally a relatively large retention of nitrogen, although there are indications that forest soils become nitrogen-saturated at total inputs above 4.0 kmolc per ha per year aluminium mobilization is the major buffer mechanism neutralizing the acidity input.
Design, characterization and application of the multiple air-lift loop bioreactor
Bakker, W.A.M. - \ 1995
Agricultural University. Promotor(en): J. Tramper; C.D. de Gooijer; H.H. Beeftink. - S.l. : Bakker - ISBN 9789054854791 - 172
chemische reacties - uitrusting - chemische eigenschappen - automatische regeling - instrumentatie - systemen - zuurstof - monoclonale antilichamen - hybridoma's - chemical reactions - equipment - chemical properties - automatic control - instrumentation - systems - oxygen - monoclonal antibodies - hybridomas
<p>A new bioreactor is introduced: the Multiple Air-lift Loop reactor (MAL). The MAL consists of a series of air-lift loop reactors within one vessel. With the MAL, a new type of geometry for air-lift reactors with an internal loop is introduced. This new geometry was characterized with respect to hydrodynamics, mixing and oxygen transfer. The hydrodynamics were described by an existing model. Hydrodynamics, mixing and oxygen transfer in the new reactor configuration were comparable to that in conventional air-lifts with an internal loop.<p>The design and use of the MAL as a reactor cascade, to approximate plug-flow behaviour, were studied. Biological model systems were used to compare the reactor series to a single vessel. These model systems included immobilized invertase and nitrifying bacteria. With the immobilized invertase it was shown that a threecompartment MAL gives an improved substrate conversion when compared to a single vessel of the same overall volume. This could be described with a previously developed model. Also for the immobilized nitrifying bacteria improved substrate conversion was shown in the comparison between a series and a single vessel. Free suspended hybridomas were used for monoclonal antibody (MAb) production. It was shown that reactor series can be useful research tools for kinetic studies. In the second vessel in the series conditions were obtained that can hardly be reached in a single vessel. Not only growth, but also death could be studied under stable conditions. A model was derived that describes hybridoma growth and their MAb production.<p>Vessels in a series can be of equal volume, but very often unequal volumes can be more advantageous. Therefore, choosing the appropriate reactor volumes is an important design step, which is discussed for different applications. Finally, a general procedure for choosing the optimal bioreactor cascade configuration for any application is given.
Effecten van hydrologische maatregelen tegen verzuring en vermesting op vegetatie, bodem en grondwater in Groot - Zandbrink : een evaluatie na twee jaar
Kemmers, R.H. ; Delft, S.P.J. van; Jansen, P.C. - \ 1994
Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 319) - 109
ecologie - hydrologie - waterverontreiniging - waterkwaliteit - neerslag - chemische eigenschappen - zure regen - bodemchemie - graslanden - ecohydrologie - natuurgebieden - gelderland - gelderse vallei - ecology - hydrology - water pollution - water quality - precipitation - chemical properties - acid rain - soil chemistry - grasslands - ecohydrology - natural areas
Bodemkundig onderzoek in het kader van obn
A data base for European forest soils
Reinds, G.J. - \ 1994
Wageningen : DLO Winand Staring Centre (Technical document / DLO Winand Staring Centre 7) - 77
bosschade - zure regen - fysicochemische eigenschappen - bodemeigenschappen - bodemchemie - neerslag - chemische eigenschappen - zuurgraad - databanken - europa - forest damage - acid rain - physicochemical properties - soil properties - soil chemistry - precipitation - chemical properties - acidity - databases - europe
Verkenning moerasontwikkeling IJsselmeerkust : abiotische kansrijkdom en landbouwperspectief
Farjon, J.M.J. ; Eck, W. van; Lith, J. van - \ 1994
Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 355) - 50
plantengemeenschappen - zwampen - wetlands - natuurreservaten - herstel - grondwater - chemische eigenschappen - rivieren - waterlopen - kanalen - water - oppervlaktewater - rivierwater - eigenschappen - landbouwsituatie - economische situatie - natuur - natuurtechniek - ijsselmeer - plant communities - swamps - nature reserves - rehabilitation - groundwater - chemical properties - rivers - streams - canals - surface water - river water - properties - agricultural situation - economic situation - nature - ecological engineering - lake ijssel
On the statistical analysis of vegetation change: a wetland affected by water extraction and soil acidification
Braak, C.J.F. ter; Wiertz, J. - \ 1994
Journal of Vegetation Science 5 (1994)3. - ISSN 1100-9233 - p. 361 - 372.
plantensuccessie - drainage - neerslag - chemische eigenschappen - zuurgraad - zure regen - statistische analyse - statistische inferentie - natuurbescherming - beleid - bedrijfsvoering - wetlands - polders - plant succession - precipitation - chemical properties - acidity - acid rain - statistical analysis - statistical inference - nature conservation - policy - management
A case study is presented on the statistical analysis and interpretation of vegetation change without precise information on environmental change. The changes in a vegetation of a Junco-Molinion grassland are evaluated on the basis of relevés of 1977 and 1988 (20 plots) from a small nature reserve on moist oligotrophic, Pleistocene sands in The Netherlands. The changes are attributed to water withdrawal (since 1972) and soil acidification. Their effect on the vegetation is inferred from data on water depth and acidity collected in 1988. Many species typical of moist oligo- or mesotrophic and neutral haylands and several rare species such as Parnassia palustris, Selinum carvifolia and Ophioglossum vulgare decreased in abundance. A few species increased, especially Anthoxantum odoratum, Holcus lanatus and Plantago lanceolatum. A significant decrease was found in the mean Ellenberg indicator value for moisture and for acidity. The mean indicator value for nutrients did not change significantly. Multivariate analysis of the species data by redundancy analysis demonstrated the overall significance of the change in species composition between 1977 and 1988 (P<0.01, Monte Carlo permutation). The spatial and temporal variation in the species data was displayed in ordination diagrams and interpreted in terms of water depth and pH. A simple model is developed to infer the change in water depth and pH from the relevé data and recent data on water depth and pH. Because the correlation between water depth and pH made joint estimation of the changes useless, the change in pH was estimated for a series of likely changes in water depth. For the most likely change in water depth, significant acidification was inferred from the change in vegetation.
Mineralogy of a holocene chronosequence on andesitic beach sediments in Costa Rica
Nieuwenhuyse, A. ; Jongmans, A.G. ; Breemen, N. van - \ 1994
Soil Science Society of America Journal 58 (1994)2. - ISSN 0361-5995 - p. 485 - 494.
chemische eigenschappen - kleimineralen - costa rica - fysicochemische eigenschappen - bodemvorming - chemical properties - clay minerals - physicochemical properties - soil formation
Weathering and neoformation of minerals in a Holocene (
Growth and nutrition of Douglas fir, Scots pine and pedunculate oak in relation to soil acidification
Visser, P.H.B. de - \ 1994
Agricultural University. Promotor(en): N. van Breemen; G.R. Findenegg; W.G. Keltjens. - S.l. : De Visser - ISBN 9789054852902 - 185
bosbouw - houtteelt - bosbouwkundige handelingen - groei - milieufactoren - bomen - bodemchemie - bodemaciditeit - verzuring - beluchting - voedingsstoffenopname (planten) - bodem ph - plantenfysiologie - neerslag - chemische eigenschappen - zuurgraad - zure regen - forestry - silviculture - forestry practices - growth - environmental factors - trees - soil chemistry - soil acidity - acidification - aeration - nutrient uptake - soil ph - plant physiology - precipitation - chemical properties - acidity - acid rain
<p>In a Douglas fir ( <em>Pseudotsuga menziesii</em> (Mirb.) Franco) and in a Scots pine ( <em>Pinus sylvestris</em> L.) stand on sandy soil in the Netherlands, inputs of water, nutrients and acid loads were changed for four years. Effects of soil changes on growth and nutrition were compared with similar foreign experiments, and with some soil-tree relationships in an oak ( <em>Quercus robur</em> L.) stand, which had different soil types within the site. Water limitations in the stands were demonstrated by a 40% to 50% increase in tree basal area growth from water additions of 3 mm d <sup>-1</SUP>or more. Needle N and K contents were depressed and needle shedding was retarded in autumn by irrigation in the Douglas fir stand. In both coniferous stands mineralization and nitrate leaching were enhanced by the moister soil conditions. The modest growth response to nutrient applications in addition to irrigation, proved that no nutrient deficiencies were present at the sites, although foliar P and K increased instantly. The application of dissolved K, Mg and Ca to both acid forest soils increased Al dissolution and decreased Ca/Al ratios in soil solution. This soil reaction was even stronger when applying dissolved (NH <sub>4</sub> ) <sub>2</sub> SO <sub>4</sub> and was explained by the combined effect of soil exchange processes and root uptake of the applied cations, both increasing soil acidification. The applied (NH <sub>4</sub> ) <sub>2</sub> SO <sub>4</sub> initially enhanced tree growth, later followed by growth reduction in the forest stand and tree death in a pot trial at similar NH <sub>4</sub> supply rates.<p>Douglas fir growth was higher at optimal water and nutrient applications when atmospheric loads were excluded. The reduced NH <sub>4</sub> inputs resulted in a decrease of NO <sub>3</sub> leaching, in a lower needle N concentration and tended to decrease Al concentrations and Al/Ca ratios in soil solution relative to the treatment with atmospheric loads.<p>Transpiration of Douglas fir, as measured from sapflow, was drastically reduced during summer drought. Irrigated trees showed optimal transpiration rates and were found to absorb water more readily after rain events relative to previously water-stressed trees. NH <sub>4</sub> applications in a pot trial initially increased shoot growth and transpiration of juvenile Douglas fir, but strong soil acidification later impaired root functioning and water uptake.
Soil response to acid deposition at different regional scales : field and laboratory data, critical loads and model predictions
Vries, W. de - \ 1994
Agricultural University. Promotor(en): N. van Breemen; A. Breeuwsma. - S.l. : De Vries - ISBN 9789032702557 - 487
fysicochemische eigenschappen - bodemeigenschappen - bodemchemie - anorganische verbindingen - mineralen - neerslag - chemische eigenschappen - zuurgraad - zure regen - onderzoek - modellen - nederland - physicochemical properties - soil properties - soil chemistry - inorganic compounds - minerals - precipitation - chemical properties - acidity - acid rain - research - models - netherlands - cum laude
<p>Enhanced soil, ground water and surface water acidification by elevated deposition of S and N compounds is one of the most important large-scale environmental problems today. This thesis deals with the quantification of:<br/>(i) natural and man-induced sources of acidification in agricultural soils and forest soils in the Netherlands;<br/>(ii) present impacts of atmospheric S and N deposition on the solution chemistry of acid sandy forest soils in the Netherlands;<br/>(iii) various buffermechanisms (i.e. mineral weathering, cation exchange and AI dissolution) in acid sandy soils in the Netherlands;<br/>(iv) average critical deposition levels (loads) for N and acidity (N and S) for forests, heathlands, ground water and surface water in the Netherlands;<br/>(v) spatial variability in critical loads for N, S and acidity and the degree by which these loads are exceeded at present on forests in the Netherlands and in Europe;<br/>(vi) long-term impacts of acidic deposition on representative non-agricultural soils;<br/>(vii) spatial variability in long-term impacts of acidic deposition on forest soils in the Netherlands and in Europe.<br/> <p>Quantification was performed on the basis of interpretation of literature information, combined with field research (i and ii), laboratory research (iii), and model research, (iv, v, vi and vii). In order to derive critical loads, steady-state soil models were developed, i.e. a one-layer model (START) for application on a European scale and a multi-layer model (MACAL) for application on a national scale. Similarly, two dynamic soil models were developed to assess the long-term soil response to acidic deposition, i.e. a onelayer model (SMART) for application in Europe and a multi-layer model (RESAM) for application in the Netherlands.<p>Results showed that:<br/>(i) the contribution of acid deposition to soil acidificatiom in the Netherlands is dominant in non- calcareous forest soils (≥80%), intermediate in non-calcareous agricultural soils (≤50%) and minor in calcareous soils (≤20%);<br/>(ii) S0 <sub>4</sub> behaves conservative in Dutch forest soils, whereas N is largely retained. Despite the high N deposition, actual soil acidification, which is mainly manifested by leaching of AI associated with SO <sub>4</sub> and NO <sub>3</sub> leaching, is dominantly caused by S deposition;<br/>(iii) dissolution of AI from secondary inorganic AI compounds is the dominant buffermechanism in acid sandy (forest) soils. The dissolution rate of AI can be described well as a function of the secondary AI pool and the degree of undersaturation with respect to gibbsite;<br/>(iv) average critical N loads for forests, heathlands, ground waters and surface waters in the Netherlands generally vary between 500 mol <sub>c</sub> ha <sup>-1</SUP>yr <sup>-1</SUP>('sensitive' heathlands and surface waters) and 3600 mol <sub>c</sub> ha <sup>-1</SUP>yr <sup>-1</SUP>('insensitive' ground waters). Average critical acid loads are generally lower and range between 400 mol <sub>c</sub> ha <sup>-1</SUP>yr <sup>-1</SUP>('sensitive' ground- and surface waters) to 1700 mol <sub>c</sub> ha <sup>-1</SUP>yr <sup>-1</SUP>('insensitive' forests and ground waters);<br/>(v) critical loads are largely exceeded in Central and Western Europe both in N (up to 3500 mol <sub>c</sub> ha <sup>-1</SUP>yr <sup>-1</SUP>) and S (up to 12000 mol <sub>c</sub> ha <sup>-1</SUP>yr <sup>-1</SUP>). In the Netherlands largest exceedances occur in areas with intensive animal husbandry. There emission reductions of more than 80% are needed to meet the critical loads;<br/>(vi) long-term continuation of present atmospheric deposition causes a depletion of the pool of secondary AI compounds, both in forest soils and dune soils of the Netherlands, leading to extremely low pH values. However, reduction of atmospheric deposition levels leads to a fast improvement of the soil solution quality (decreased concentrations in SO <sub>4</sub> , NO <sub>3</sub> and AI and increased pH);<br/>(vii) deposition scenarios including current reduction plans with respect to S and N emission lead to an improvement in the soil solution quality below forests in the Netherlands, but not in Europe.
Amstelland-West; toepassing van de modellen DYNHYD en EUTROWASP.
Aalderink, R.H. ; Alphen, J.C.A. van; Mankor, J. ; Smit, D. de - \ 1994
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 18 (1994). - ISSN 0166-8439 - p. 534 - 51.
kanalen - chemische eigenschappen - afvoer - modellen - onderzoek - rivieren - waterlopen - oppervlaktewater - water - amsterdam - noord-holland - utrecht - canals - chemical properties - discharge - models - research - rivers - streams - surface water
Time trends & mechanism of soil acidification
Wesselink, L.G. - \ 1994
Agricultural University. Promotor(en): N. van Breemen; J.J.M. van Grinsven. - S.l. : Wesselink - ISBN 9789054852896 - 129
zure gronden - kattekleigronden - bosbouw - verzuring - bodem ph - bodemaciditeit - neerslag - chemische eigenschappen - zuurgraad - zure regen - acid soils - acid sulfate soils - forestry - acidification - soil ph - soil acidity - precipitation - chemical properties - acidity - acid rain
<p>The effects of acid atmospheric deposition on forest ecosystems have been studied intensively in the past two decades. Measurements of element budgets in forested ecosystems throughout the world have shown that acid deposition may deplete stores of exchangeable base cations in the soil, decrease the soil pH, increase rates of mineral weathering, and release potentially toxic Al into the soil solution. In summary, acid atmospheric deposition can strongly alter the chemical environment for living organisms.<p>In this thesis the mechanisms that may control those phenomena are studied, with emphasis on soil chemical processes. Central in this study are long and comprehensive data sets from continuous measurements (monitoring) of element fluxes in forest ecosystems, specifically from the Solling experimental forest in Germany.<p><strong>Base Cations</strong><p>Using over 20 years of data on deposition and soil chemistry at Solling, chapter 2 discusses how long-term changes in atmospheric deposition of acid anions and base cations affect dissolved and exchangeable pools of base cations in the soil, through the process of cation exchange. Positive effects of declining SO <sub>4</sub> deposition in the 1980s, which potentially reduces leaching of base cations from the soil, were partially offset by (i) continued high concentrations of dissolved SO <sub>4</sub> in the soil and (ii) declining deposition of the base cations Ca and Mg. The latter appears to result from stricter controls on particle emissions from fuel combustion and industrial processes. Recent studies indicate that declining deposition of base cations is observed in other regions of Europe and North America as well. This is a matter of concern as forests may be sensitive to changes in base cation deposition which is, together with mineral weathering, the most important source of nutrients to forests on acidified soils.<p>In chapter 3 we quantified rates of mineral weathering at Solling, as a source of nutrients and acid neutralization. Estimates of field weathering rates were obtained from, (i) long-term input- output mass balances, correcting for changes in stores of exchangeable base cations in the soil, and (ii) elemental analysis of the soil profile. At Solling, rates of supply of Ca, K and Na by weathering are much lower than by atmospheric deposition; for Mg the contributions are of similar magnitude. This emphasizes (i) the relevance of atmospheric deposition of base cations as a nutrient source to the Solling forests, and (ii) the concern with respect to its present decline. To investigate mechanisms of mineral weathering of Mg and K, a series of laboratory weathering experiments with soils from Solling were conducted.<p>These focused on weathering of illite, the dominant mineral source of K and Mg. A major problem in quantifying rates of mineral weathering is the large discrepancy in rates obtained in laboratory studies and field estimates, with laboratory rates being generally one to three orders higher. In the laboratory, effects of pH, temperature, and soil solution composition on illite weathering were studied. Corrected for the effects of these factors, Mg and K release rates from illite measured in the laboratory were comparable (K) or a factor 2 to 4 higher (Mg) than rates inferred from field methods. It is concluded that field estimates of weathering rates, from elemental analysis of the soil profile or input-output flux balances, remain necessary to obtain reliable estimates of base cation weathering rates.<p><strong>Anions</strong><p>In a simplified way, anions in the soil solution can be regarded as carriers of base and acid cations, through charge balance constraints. Understanding the processes that determine dissolved concentrations of these components in the soil is therefore of prior importance. In chapter 4 we discussed the processes that govern the mobility of dissolved Cl, SO <sub>4</sub> and NO <sub>3</sub> in the Solling spruce soil over a period of 18 years. For this purpose a simulation model describing soil hydrology and a number of biogeochemical processes was introduced. Using throughfall water and concentrations as input to the model, concentrations of Cl in soil solutions were successfully simulated, a requirement to further study components that interact chemically or biologically with the soil.<p>Sorption of SO <sub>4</sub> is of significance in the soils at Solling due to comparatively high contents of Al and Fe oxides. By contrast, in the mineralogically poor sandy soils in the Netherlands SO <sub>4</sub> often behaves chemically nearly conservative. The steep increase in dissolved SO <sub>4</sub> in the Solling spruce soil during the mid-1970s was modelled adequately using adsorption parameters reported in literature, and was explained by a steep adsorption isotherm and a state of near saturation of SO <sub>4</sub> sorption sites in the early 1970s, at the start of the monitoring program. Rates of desorption of SO <sub>4</sub> in the 1980s in response to declining SO <sub>4</sub> deposition, described by the same model, were less than those measured in the field. In the absence of evidence for alternative controls on dissolved SO <sub>4</sub> , like jurbanite (AlOHSO <sub>4</sub> dissolution, the mechanism of SO <sub>4</sub> desorption remains unclear.<p>The model increased our understanding of the processes that control repeated 3-year cycles of high and low concentrations of N0 <sub>3</sub> in deeper layers (90 cm) of the Solling spruce soil. Recently, there is increasing interest in N-dynamics in forest ecosystems, as N-saturation has been hypothesized as an additional cause of forest decline. In the Solling spruce soil, concentrations of N0 <sub>3</sub> water leaving the soil profile increased when the N-flux into the <em>mineral soil,</em> from deposition and net mineralization, exceeded the N uptake capacity of the forest at a threshold value of around 4 kmol ha <sup>-1</SUP>yr <sup>-1</SUP>. At present, total deposition of N on the spruce forest amounts to 3.3 kmol ha <sup>-1</SUP>yr <sup>-1</SUP>and is close to this threshold value. This points to the critical role of N mineralization processes in the litter layer, where large stores of N have accumulated over the past 25 years. The annual release of N from the spruce litter layer was positively correlated with rainfall. This was apparent from large N releases from litter in relatively wet years which subsequently increased NO <sub>3</sub> concentrations at the 90 cm depth.<p><strong>Aluminum</strong><p>The main acid neutralizing process in acid forest soils under high acid loads is the release of AI to the soil solution. Soil acidification models generally describe the solubility of reactive soil Al by equilibrium or kinetic dissolution of Al-trihydroxide (Al(OH) <sub>3</sub> ), In chapters 5 and 6, we scrutinized the evidence for this reaction mechanism from extensive sets of field data, but found little support for the gibbsite model. By contrast, evidence points to AI binding to soil organic matter as a control of dissolved Al, even when organic matter contents are low. In chapter 6 a new, mechanistic, and yet simple model was presented that explained much of the spread in Al-solubility, as observed in 29 different soil layers from 18 forest soils. The model describes Al-solubility as a function of the degree to which humus binding sites are saturated with Al. It involves only two soil specific parameters, the organic C content of the soil and an estimate of the pool of organically bound soil Al, and may therefore be easily incorporated in current soil acidification models.<p>The soils studied in this thesis generally receive high loads of acid deposition, and acidity is largely neutralized by release of Al in the upper 20 cm of the mineral soil. It has been suggested that in surface layers of these soils depletion of reactive soil Al may result within decades. The depletion hypothesis was put to test by measuring pools of organically bound soil Al in old (around 1980) and new (around 1993) samples from research sites at Hackfort and Gerritsfles in the Netherlands, and Solling in Germany. Indeed, significant decreases with time were found. Independently measured depletion of organically bound soil Al and declining Al solubility, as observed previously from 6 years of field monitoring at Hackfort in the 1980s, proved to be consistent with the humus-Al model presented in this thesis. Rates of depletion of organically bound soil Al at Hackfort, the Netherlands, during a period of about 13 years were lower than expected from long-term monitoring of Al solute fluxes. This suggests that pools other than organically bound Al, i.e. silicates and inorganic Al hydroxides, may contribute to Al mobilization as well. Literature indicates that release of Al from these pools may be kinetically constrained. The current discussion on whether Al activities in solutions of acid forest soils are controlled by kinetically constrained (time dependent) dissolution of inorganic Al hydroxides or by equilibrium binding to soil organic matter is, in my view, clarified when the kinetic and the equilibrium process are regarded as sequential; kinetic release supplying Al to the organic exchanger, which equilibrates with the soil solution.<p>GENERAL CONCLUSIONS<p>1. In the recent past, deposition of SO <sub>4</sub> , Ca and Mg on the German Solling forests has declined significantly as a result of reduced industrial emissions.<br/>2. Results from Solling indicate that soil de-acidification, i.e. an increase in the pool of exchangeable base cations, as a result of declining SO <sub>4</sub> deposition may be offset by i) continuous release of sorbed SO <sub>4</sub> from the soil and ii) declining deposition of base<br/>cations.<br/>3. Weathering rates of Ca, K and Na at Solling, Germany, are much lower than their supply by atmospheric deposition; for Mg the contributions of deposition and weathering are of similar magnitude.<br/>4. Illite is the main mineral source of Mg and K at Solling. Although coming from the same mineral source, the two cations are released by different mechanisms. Magnesium release is controlled by chemical kinetic processes and its release is highly<br/>pH dependent (R≈(H <sup>+</SUP>) <sup>0.8</SUP>), whereas K is released from interlayers by diffusion, a process that showed independent of pH.<br/>6. A six-fold increase of dissolved SO <sub>4</sub> in the Solling spruce soil (90 cm) in the mid 1970s, and continuously high concentrations thereafter, is explained by 'peaking' SO <sub>4</sub> deposition loads in the mid-1970s that entered a mineral soil where the SO <sub>4</sub> sorption capacity was nearly saturated.<br/>6. Repeated 3-year cycles of high and low concentrations of NO <sub>3</sub> in deeper layers (90 cm) of the Solling spruce soil are related to excess release of N from the litter layer in comparatively wet years.<br/>7. Strong changes in pH and less strong changes in pAl (-log{Al <sup>3+</SUP>}) in response to varying acid anion concentrations, generally observed in acid forest soils, and the measured increased of CEC with time in the surface soil of the Solling spruce sites, support the hypothesis of Al solubility control by complexation to soil organic matter.<br/>8. Data from 29 soil layers of 18 forest soils, covering a range in soil pH, Al activities, and reactive soil Al pools indicate that Al solubility control by complexation to soil organic matter is a general phenomenon, even when organic C contents are low.<br/>9. Much of the variation in Al solubility observed in 29 different soil layers of 18 forest soils is explained by the organically bound Al: soil C ratio.<br/>10. In surface soils where stores of organically bound Al are low and release rates high depletion of reactive, organically bound, soil Al is significant on a time scale of 12 to 14 years only.<br/>11. Independently measured declines in (i) Al solubility in surface soils at Hackfort the Netherlands, from 6 years of monitoring of soil water chemistry and (ii) pools of organically bound soil Al, are consistent with the Al-humus equilibrium model<br/>proposed in this thesis.<br/>12. In acid forest soils where dissolved Al activities are controlled by equilibrium complexation to soil organic matter, kinetically constrained release of Al from inorganic Al pools may well contribute to acid neutralization.
The solubility of aluminum in acidic forest soils: long-term changes due to acid deposition.
Mulder, J. ; Stein, A. - \ 1994
Geochimica et Cosmochimica Acta 58 (1994). - ISSN 0016-7037 - p. 85 - 94.
bodem - aluminium - bruine bosgronden - neerslag - chemische eigenschappen - zuurgraad - zure regen - uitspoelen - soil - brown forest soils - precipitation - chemical properties - acidity - acid rain - leaching
Basenverzadiging in soortenrijke trilvenen
Wirdum, G. van - \ 1993
In: Effectgerichte maatregelen tegen verzuring en eutrofiering in natuurterreinen : [proceedings van een symposium op 30 oktober 1992] / Cals, M., de Graaf, M., Roelofs, J., KU Nijmegen [etc.] - ISBN 9789037301748 - p. 97 - 126.
plantengemeenschappen - zwampen - wetlands - neerslag - chemische eigenschappen - zuurgraad - zure regen - natuurbescherming - beleid - bedrijfsvoering - nederland - plant communities - swamps - precipitation - chemical properties - acidity - acid rain - nature conservation - policy - management - netherlands
De invloed van atmosferische depositie op diatomeeen en chemische samenstelling van het water in sprengen, beken en bronnen
Dam, H. van; Mertens, A. ; Janmaat, L.M. - \ 1993
Wageningen : DLO-IBN (IBN - rapport 052)
rivieren - waterlopen - kanalen - oppervlaktewater - rivierwater - chemische samenstelling - neerslag - chemische eigenschappen - zuurgraad - zure regen - bacillariophyta - verontreiniging - waterorganismen - nederland - droge depositie - biologische eigenschappen - rivers - streams - canals - surface water - river water - chemical composition - precipitation - chemical properties - acidity - acid rain - pollution - aquatic organisms - netherlands - dry deposition - biological properties
Reductie van ammoniakemissie : mogelijkheden en kosten van beperking van ammoniakemissie op nationaal en regionaal niveau
Oudendag, D.A. - \ 1993
Den Haag : LEI-DLO (Onderzoekverslag / Landbouw-Economisch Instituut 102) - ISBN 9789052421940 - 82
luchtverontreiniging - ammoniak - emissie - vervluchtiging - neerslag - chemische eigenschappen - zuurgraad - zure regen - prijzen - prijsvorming - kosten - wiskundige modellen - onderzoek - nederland - mestoverschotten - air pollution - ammonia - emission - volatilization - precipitation - chemical properties - acidity - acid rain - prices - price formation - costs - mathematical models - research - netherlands - manure surpluses
SMB - a Simple Mass Balance model to calculate critical loads : model description and user manual
Salm, C. van der; Voogd, J.C.H. ; Vries, W. de - \ 1993
Wageningen : DLO Winand Staring Centre (Technical document / DLO Winand Staring Centre 11) - 30
bodem - stikstof - fosfor - neerslag - chemische eigenschappen - zuurgraad - zure regen - modellen - onderzoek - nederland - soil - nitrogen - phosphorus - precipitation - chemical properties - acidity - acid rain - models - research - netherlands
De chemische samenstelling van bodem en bodemvocht van duingronden in de provincie Zuid-Holland
Vries, W. de - \ 1993
Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 280) - 31
duinen - duingronden - bodem ph - bodemaciditeit - bodemoplossing - neerslag - chemische eigenschappen - zuurgraad - zure regen - nederland - zuid-holland - dunes - dune soils - soil ph - soil acidity - soil solution - precipitation - chemical properties - acidity - acid rain - netherlands
Time series analysis of changes in the soil solution: evidence for approach to nitrogen saturation in Dutch forest soils.
Stein, A. ; Breemen, N. van - \ 1993
Agriculture, Ecosystems and Environment 47 (1993). - ISSN 0167-8809 - p. 147 - 158.
zure gronden - kattekleigronden - neerslag - chemische eigenschappen - zuurgraad - zure regen - statistiek - waarschijnlijkheidsanalyse - wiskunde - acid soils - acid sulfate soils - precipitation - chemical properties - acidity - acid rain - statistics - probability analysis - mathematics
Sulfur cycling in two Dutch moorland pools
Marnette, E.C.L. - \ 1993
Agricultural University. Promotor(en): N. van Breemen; T.E. Cappenberg. - S.l. : Marnette - ISBN 9789054851561 - 143
kringlopen - meren - plassen - waterverontreiniging - waterkwaliteit - eutrofiëring - zwavel - neerslag - chemische eigenschappen - zuurgraad - zure regen - stilstaand water - nederland - cycling - lakes - ponds - water pollution - water quality - eutrophication - sulfur - precipitation - chemical properties - acidity - acid rain - standing water - netherlands
<p>Due to atmospheric acid deposition, the chemistry of many moorland pools has changed, resulting in changes in their fauna and flora. Most moorland pools are sensitive to acid loading because underlying and surrounding soils are low in chemical buffering capacity. Biological processes in the sediment like denitrification and SO <sub>4</sub><sup>2-</SUP>reduction are of major importance to internal alkalinization necessary to neutralize the atmospheric input of potential acidifying N and S components. This study deals with the cycling of sulfur in moorland pools and was aimed at a better understanding of the factors influencing the S cycle in these freshwaters.<p><em>Characterization and quantification of sulfur pools in sediment and overlying water column. Determination of spatial variability of chemical characteristics related to S-cycling.</em><p>In highly organic moorland pool sediment (mean C content of top 10 cm = 9.8% dwt) about 46% of the total S is in organic S form, whereas in sandy sediment (mean C content = 1.4% dwt) the organic S fraction makes up about 75% of the total S pool. The sediments of the moorland pools Gerritsfles and Kliplo, have been compared statistically with respect to total S and S-related sediment contents (Chapter 6). The pools differ significantly in their horizontal and vertical distribution of S. Statistical analyses indicate that spatial variation of S in Kliplo is due to organically bound S. For Gerritsfles spatial interrelation between C, S or Fe could not be recognized. As evidenced by this study, a choice for a measurement unit like mass fraction (g g <sup>-1</SUP>) or volumetric mass (Mg cm <sup>-3</SUP>) is crucial for the interpretation of spatial variability. In spatial studies of sediment constituents, it is essential to express contents of these constituents in volumetric mass fractions, since spatial sediment patterns are often obscured by spatial variations in bulk density. Taking into account spatial variability is concise for a proper quantification of S-budgets of pools or lakes.<p><em>Determination of SO <sub>4</sub><sup>2-</SUP>reduction rates and transformation rates of SO <sub>4</sub><sup>2-</SUP>into organic and inorganic S fractions. Estimation of S oxidation rates in sediments and overlying water column.</em><p>In GerritsfIes S cycling near the sediment/water boundary was investigated by measuring (1) SO <sub>4</sub><sup>2-</SUP>reduction rates in the sediment, (2) depletion of SO <sub>4</sub><sup>2-</SUP>in the overlying water column and (3) release of <sup>35</SUP>S from the sediment into the water column (Chapter 2). Two locations differing in sediment type (highly organic and sandy) were compared with respect to reduction rates and depletion of SO <sub>4</sub><sup>2-</SUP>in the overlying water.<p>Sulfate reduction rates, estimated by diagenetic modelling and whole core <sup>35</SUP>SO <sub>4</sub><sup>2-</SUP>injection, ranged from 0.27 to 11.2 mmol m <sup>-2</SUP>d <sup>-1</SUP>. Rates of SO <sub>4</sub><sup>2-</SUP>consumption in the overlying water were estimated by changes in SO <sub>4</sub><sup>2-</SUP>concentration over time in <em>in situ</em> enclosures and varied from -0.51 to 1.81 mmol m <sup>-2</SUP>d <sup>-1</SUP>. Maximum rates of oxidation to SO <sub>4</sub><sup>2-</SUP>in July 1990 estimated by combination of SO <sub>4</sub><sup>2-</SUP>reduction rates and rates of <em>in situ</em> SO <sub>4</sub><sup>2-</SUP>uptake in the enclosed water column were 10.3 and 10.5 mmol m <sup>-2</SUP>d <sup>-1</SUP>at an organic rich site and at a sandy site respectively.<p>Experiments with <sup>35</SUP>S <sup>2-</SUP>and <sup>35</SUP>SO <sub>4</sub><sup>2-</SUP>tracer suggested (1) a rapid formation of organically bound S from dissimilatory reduced SO <sub>4</sub><sup>2-</SUP>and (2) transport of mainly non-SO <sub>4</sub><sup>2-</SUP>-S, from the sediment into the overlying water.<br/>Sulfate reduction rates in sediments with higher volumetric mass fraction of organic matter did not significantly differ from those in sediments with a lower mass fraction of organic matter.<p><em>The role of inorganic S,</em> with <em>emphasis on pyrite, in the S cycle of Gerritsfles and Kliplo.</em><p>In Gerritsfles and Kliplo, pyrite is the most important iron sulfide phase (Chapter 3).The redox status appeared to be a main factor in determining whether pyrite or a monosulfide, defined by the content of acid volatile sulfur (AVS), is formed. Sedimentary FeS <sub>2</sub> -S/AVS-S molar ratios in sediments of Gerritsfles and Kliplo, which are overlain by a continuously oxygenated water column, were 32 and 55 respectively whereas in other lakes, where stratification caused anaerobic conditions in the hypolininion, FeS <sub>2</sub> /AVS ratios were &lt;1.<p>Framboidal pyrite, presumably formed slowly through sulfurization of iron sulfide precursors is thought to be an important pathway of pyrite formation in the freshwater sediments of Gerritsfles and Kliplo. The presence of single-crystal pyrite indicates that pyrite in both sediments may also form rapidly. The close association of pyrite framboids and organic matter, and the undersaturation of bulk porewaters with respect to amorphous FeS suggest that the framboidal pyrite is formed at microsites within organic matter. Alternating reduced and more oxic conditions in the sediment will supply Fe <sup>2+</SUP>and zerovalent sulfur respectively for the formation of pyrite. That a large fraction of pyrite is in (dead) plant cells may be explained by preferential oxidation of pyrite at locations where pyrite is not so protected against O <sub>2</sub> intrusion, in contrast to the pyrite located inside organic matter microsites.<p><em>Calculation of a chemical S-budget in both freshwater systems using models and chemical data of pool- and rainwater.</em><p>The chemical composition of surface waters of Gerritsfies and Kliplo and of incident precipitation, were monitored from 1982 to 1990. Sulfur and water budgets were calculated using a hydrochemical model developed for well-mixed nonstratifying lakes (Chapter 4). In Gerritsfies and Kliplo respectively 70 and<TT>80%</TT>of the incoming S is lost to the sediment primarily through reduction of SO <sub>4</sub><sup>2-</SUP>indicating that SO <sub>4</sub><sup>2-</SUP>reduction is an important mechanism to buffer the incoming acidic S compounds. Total atmospheric deposition of S has decreased significantly after 1986 at both locations. A model describing the sulfur budget in terms of input, output and reduction/oxidation processes predicted a fast decrease of poolwater SO <sub>4</sub><sup>2-</SUP>concentrations after a decrease of atmospheric input. However, SO <sub>4</sub><sup>2-</SUP>concentrations in the surface water were lowered only slightly or remained constant so there must be an extra source of SO <sub>4</sub><sup>2-</SUP>to the water column. Two possible mechanisms can explain this extra source of SO <sub>4</sub><sup>2-</SUP>: desorption of SO <sub>4</sub><sup>2-</SUP>from the sediment and the release of SO <sub>4</sub><sup>2-</SUP>through desiccation of a part of the pool bottom after dry summers. Further investigations would be needed to study the relative importance of these mechanisms. <em></em><p><em>Mineralization of sedimentary organic S</em><p>'Me mineralization rate of organic S compounds in Gerritsfles was estimated to reveal its importance in the overall S cycle (Chapter 5).<TT></TT>The mineralization rate of organic S was estimated indirectly from diagenetic modelling of pore water NH <sub>4</sub><sup>+</SUP>depth profiles and the ratio of organic N and S contents. Since the mineralization rates of organic N and S do not follow the stoichiometry of the contents of organic N and S, it was only possible to estimate a maximum rate of organic S mineralization. The maximum rate of organic S mineralization was 25 mmol m <sup>-2</SUP>2 y <sup>-1</SUP>, only 1-2% of the SO <sub>4</sub><sup>2-</SUP>reduction in Gerritsfles sediments so, mineralization of organic S therefore, appears to play a minor role in the overall S-cycle.
Sulfur and carbon cycling in a stratifying freshwater lake
Hordijk, C.A. - \ 1993
Agricultural University. Promotor(en): N. van Breemen; T.E. Cappenberg. - S.l. : Hordijk - ISBN 9789054851554 - 177
biocenose - ecosystemen - kringlopen - biogeochemie - koolstof - zwavel - meren - reservoirs - plassen - chemische eigenschappen - waterverontreiniging - waterkwaliteit - eutrofiëring - ecofysiologie - waterbodems - biocoenosis - ecosystems - cycling - biogeochemistry - carbon - sulfur - lakes - ponds - chemical properties - water pollution - water quality - eutrophication - ecophysiology - water bottoms
<p>This thesis is a synopsis of a ten-years research on the anaerobic breakdown of organic matter in the stratifying Lake Vechten. Special attention has been paid to the sulfur cycle and how this cycle interacts with carbon mineralization. The sediment plays an important role in the breakdown of organic matter in freshwater ecosystems. Until a few years ago, there was no insight in how mineralization processes were spatial organized in the sediment. New analytical developments have enabled to measure the steep concentration profiles in flocculent sediment layers of a few cm. These techniques are discussed in the second chapter of this thesis. Chapter 3 is more focused on field data collection and evaluation and Chapter 4 is discussing perspectives for future research.<p>The study in Lake Vechten demonstrated that the penetration depth of O <sub>2</sub> , NO <sub>3</sub><sup>-</SUP>, and SO <sub>4</sub><sup>2-</SUP>into the sediment can be limited to a few mm till a few cm in freshwaters. This is a crucial difference with marine systems where SO <sub>4</sub><sup>2-</SUP>usually penetrates much deeper.<br/>This difference makes it also expectable that microbial kinetics in freshwaters differ from those in marine sediments.<br/>The ability to measure concentration profiles across narrow depth intervals has open new ways to estimate electron acceptor consumptions by mathematical modeling. To support modeling, diffusion coefficients, adsorption effects, and kinetics were determined independently. The uptake of sulfate and nitrate in sediment in batches collected form the respiring horizon followed a first order kinetics. This indicates that electron limitation occurs in the top layer of the sediment. Assuming first order kinetics and using the measured concentration profiles, sulfate and nitrate consumption rates were estimated by the model of Berner. The estimated rates for sulfate reduction were twice lower that the values obtained from the batch experiments.<br/> <p>A notable result of the batch experiments was the fast uptake rate of nitrate and sulfate in the batches collected from the methanogenic horizon (3-7 cm). Under in situ conditions, nitrate and sulfate will not penetrate till this horizon. The absence of a 'lag time' indicated the presence of a vital sulfate and nitrate reducing community in sediment of approximately 6-14 years old.<p>In the second stage in this study we examined if the accumulated total sulfur in the sediment could give an indication on sulfate reduction rates integrated over a longer period. By comparison sulfate reduction rates and total sulfur sedimentation rates with the actual amount of sulfur present in the sediment, it appears that only about 15% of the annual sulfur input is permanently buried in the sediment. Thus, more than 80% of the sulfur is released again into the lake water column. This idea was supported by the concentration profiles of sulfur species seen in the lake-water column. The lake-water measurements also revealed that substantial more sulfur bearing species were present in the lake water column as could be explained by the sulfate, FeS, and ΣH <sub>2</sub> S pool only.<p>In the last stage of the study we have related the sulfur and carbon cycle by comparing the kinetics of the 'key metabolites' acetate and sulfate. This comparison indicated that the role of sulfate as electron acceptor in the oxidation of acetate in freshwaters is dubious. Accumulation of acetate after addition of molybdate has several times been used as evidence that sulfidogens uses mainly acetate as electron donor in marine systems. Comparable experiments in Lake Vechten indicated however that molybdate also affected other acetate consuming processes besides sulfate reduction, making conclusions from this type of inhibition experiments tentative. In conclusion, sulfate reduction does not play an important role in acetate consumption in freshwater like it does in marine systems.<p>Acetate uptake rates are relative high if compared with sulfate reduction rates and methane production rates. This indicated the existence of other quantitative important acetate consuming processes in the anaerobic part of the sediment. The acetate uptake rates did however not exceed total carbon sedimentation rates as in marine systems.
Micromorphological characterization and microchemical quantification of weathering in an alkali basalt pebble.
Jongmans, A.G. ; Veldkamp, E. ; Breemen, N. van; Staritsky, I. - \ 1993
Soil Science Society of America Journal 57 (1993). - ISSN 0361-5995 - p. 128 - 134.
chemische eigenschappen - pedologie - fysicochemische eigenschappen - bodemvorming - bodemmicromorfologie - chemical properties - pedology - physicochemical properties - soil formation - soil micromorphology
Effects of atmospheric chemistry and bark chemistry on epiphytic lichen vegetation in The Netherlands
Dobben, H.F. van; Wamelink, W. - \ 1992
Wageningen : IBN-DLO (RIN report 92/23) - 34
korstmossen - toxische stoffen - chemie - indicatorplanten - neerslag - chemische eigenschappen - zuurgraad - zure regen - bosbouw - straatbomen - houtachtige planten als sierplanten - nederland - chemische factoren - lichens - toxic substances - chemistry - indicator plants - precipitation - chemical properties - acidity - acid rain - forestry - street trees - ornamental woody plants - netherlands - chemical factors
De directe bijdrage van Pb en Cd in atmosferische depositie aan de Pb- en Cd-belasting van gras, spinazie, waspeen en tarwe in een zandige zavelgrond
Dalenberg, J.W. ; Driel, W. van - \ 1992
Haren (Gr.) : DLO-Instituut voor Bodemvruchtbaarheid (Nota / DLO-Instituut voor Bodemvruchtbaarheid 255) - 26
graslanden - spinacia oleracea - spinazie - daucus carota - penen - triticum aestivum - tarwe - hexaploïdie - chemische samenstelling - planten - chemische analyse - veldgewassen - akkerbouw - neerslag - chemische eigenschappen - zuurgraad - zure regen - bodemverontreiniging - luchtverontreiniging - cadmium - lood - grasslands - spinach - carrots - wheat - hexaploidy - chemical composition - plants - chemical analysis - field crops - arable farming - precipitation - chemical properties - acidity - acid rain - soil pollution - air pollution - lead
Emission of fumigants from soil and dispersion in air
Berg, F. van den - \ 1992
Agricultural University. Promotor(en): L. Wartena, co-promotor(en): E.H. Adema; M. Leistra. - S.l. : Van den Berg - 223
grondsterilisatie - bodemfumigatie - desinfecteren - bodem - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - organische verbindingen - bodemchemie - nematiciden - luchtverontreiniging - milieu - schade - milieueffect - fumigatie - neerslag - chemische eigenschappen - zuurgraad - zure regen - milieuhygiëne - soil sterilization - soil fumigation - disinfestation - soil - plant protection - pesticides - pesticide residues - persistence - organic compounds - soil chemistry - nematicides - air pollution - environment - damage - environmental impact - fumigation - precipitation - chemical properties - acidity - acid rain - environmental hygiene
<p>In the Netherlands, soil fumigants are used on a large scale for nematode control in arable farming. After injecting the fumigant into the soil, a fraction of the dosage of 1,3-dichloropropene and methyl isothiocyanate (formed from metham-sodium) diffuses up to the soil surface and escapes into the air.<p>The processes involved in fumigant behaviour in soil are described and the factors affecting these processes are discussed. A standard model including the most important processes is described and used to simulate the fumigation of fields injected with 1,3-dichloropropene or metham-sodium. It was computed that up to a few tens of percent of the dosage of the fumigant can be emitted into the air during the first three weeks after injection.<p>The impact of several simplifications in the standard model on the rate and extent of emission of fumigant into the air was evaluated. The effect of a fumigant content- dependent rate coefficient for the transformation of fumigant in soil and that of changes in soil moisture content on the rate and extent of emission into the air was computed to be substantial. Although a diurnally changing soil temperature was computed to affect the rate of emission of fumigant into the air substantially, its effect on the cumulative emission in time, compared with a soil system at the average temperature, was computed to be negligible.<p>Measurements on the one-hour concentrations of methyl isothiocyanate and 1,3-dichloropropene in air were done around two fields injected with metham-sodium and around two other fields injected with 1,3-dichloropropene. Concentrations measured in air were compared with those computed using a gaussian plume model. The comparatively large differences between the computed and measured concentrations in the air during the first few days after injection could be ascribed to an underestimation of the source strength of the emission. Improving the description of the pattern of concentrations of fumigant in air would require more detailed measurements on input parameters for the dispersion model.<p>In two consecutive years, 6-hour concentrations of 1,3-dichloropropene and methyl isothiocyanate were measured at two locations in a region with intensive use of soil fumigants. For some weeks with many fumigations in this region, the concentration of fumigant in air at a receptor site, with representative fumigated fields at different upwind distances, was computed using a gaussian plume model. The computed and measured concentrations were of the same order of magnitude.
Impact of acid atmospheric deposition on the biogeochemistry of moorland pools and surrounding terrestrial environment.
Dobben, H.F. van; Mulder, J. ; Dam, H. van; Houweling, H. - \ 1992
Wageningen : Pudoc (Agricultural research reports 931) - ISBN 9789022010723 - 232
wetlands - bosbouw - bomen - heidegebieden - luchtverontreiniging - milieu - schade - milieueffect - trofische graden - neerslag - chemische eigenschappen - zuurgraad - zure regen - stilstaand water - ecologie - bossen - verontreiniging - forestry - trees - heathlands - air pollution - environment - damage - environmental impact - trophic levels - precipitation - chemical properties - acidity - acid rain - standing water - ecology - forests - pollution
Protocols voor de verwerking van data afkomstig uit routinematig onderzoek.
Aalderink, R.H. - \ 1992
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 25 (1992). - ISSN 0166-8439 - p. 463 - 467.
chemische eigenschappen - hydrologie - instrumenten (meters) - wiskunde - meting - monitoring - waarschijnlijkheidsanalyse - statistiek - water - netwerken - chemical properties - hydrology - instruments - mathematics - measurement - probability analysis - statistics - networks
Het verband tussen N-toevoer en de nitraatconcentratie van het grondwater op akkerbouwbedrijven
Erp, P.J. van; Boumans, L.J.M. ; Kloet, C.J. ; Oenema, O. ; Duijvenbooden, W. van - \ 1991
Meststoffen : Dutch/English annual on fertilizers and fertilization (1991). - ISSN 0169-2267 - p. 38 - 41.
grondwater - chemische eigenschappen - bodem - uitspoelen - stikstofmeststoffen - bodemverontreiniging - luchtverontreiniging - mineralen - boekhouding - nitraten - stikstof - groundwater - chemical properties - soil - leaching - nitrogen fertilizers - soil pollution - air pollution - minerals - accounting - nitrates - nitrogen
Colonization of arable fields by earthworms in a newly reclaimed polder in The Netherlands: preliminary results.
Marinissen, J.C.Y. - \ 1991
In: Advances in management and conservation of soil fauna : Papers and proceedings of the 10th International Soil Zoology Colloquium held during August 7-13, 1988, at Bangalore, India. - - p. 341 - 348.
chemische eigenschappen - aardwormen - fysicochemische eigenschappen - bodemvorming - flevoland - chemical properties - earthworms - physicochemical properties - soil formation
Salinity management in river basins : modelling and management of the salt-affected Jarreh Reservoir (Iran)
Shiati, K. - \ 1991
Agricultural University. Promotor(en): W.H. van der Molen; J.H.G. Verhagen. - S.l. : Shiati - 183
rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - chemische eigenschappen - waterbeheer - bodem - natrium - verbetering - verzilting - modellen - onderzoek - waterwegen - zoutgehalte - stroomgebieden - drainage - iran - rivers - streams - canals - surface water - water pollution - water quality - chemical properties - water management - soil - sodium - improvement - salinization - models - research - waterways - salinity - watersheds
<p><TT>The sources and origin of salts in the basin of the two salt- affected Shapur and Dalaki rivers (Southern Iran) and the processes involved in salinization have been studied. The extent of water deterioration have been identified by examining spatial changes in the rivers water quality. Among salinity management measures pertaining to water quality, the engineering measures are investigated. It appears that the construction and management of the planned Jarreh Reservoir on the Shapur River is the most feasible one.</TT><p><TT>The dynamic reservoir simulation model, - DYRESM (Imberger, et al., 1978, Version 6.4) is adapted to simulate the salinity/temperature distribution, long-term behaviour and response to various management policies in this reservoir. A simplified method to account for the effect of sediment particles on density of inflows and the inflowing processes in mild bed slope reservoirs is introduced. The method applies only to the steady motion of a turbidity current that is neither depositing nor eroding sediments. The vertical propagation of sediment has not been modelled. This applies to those substances (like dissolved salt) that are not reacting physically or (bio)chemically with suspended particles.</TT><p><TT>Various management options to minimize the salinity build-up in the reservoir are examined. Among these, the diversion of the most saline part of the summer flows to a point downstream of the last irrigation intakes will result in a significant water quality improvement. At the end of a 5-year simulation, only a weak salinity gradient remains in the reservoir. Based on simulations, using 15 years of data, and the salt balance calculation, the long-term behaviour of the Jarreh Reservoir is studied, It is shown that the salinity in the reservoir is largely determined by annual variabilty in the river discharge.</TT>
Effecten van atmosferische depositie op de chemische samenstelling van grondwater onder bos.
Mulder, J. ; Beek, C.G.E.M. van; Dierx, H.A.L. - \ 1991
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 24 (1991). - ISSN 0166-8439 - p. 490 - 493.
waterkwaliteit - verontreinigingsbeheersing - grondwaterverontreiniging - bescherming - preventie - verwijdering - neerslag - chemische eigenschappen - zuurgraad - zure regen - bosbouw - watererosie - infiltratie - oppervlakkige afvoer - zure depositie - overijssel - water quality - pollution control - groundwater pollution - protection - prevention - removal - precipitation - chemical properties - acidity - acid rain - forestry - water erosion - infiltration - runoff - acid deposition
Mapping critical loads : a guidance to the criteria, calculations, data collection and mapping of critical loads
Sverdrup, H. ; Vries, W. de; Henriksen, A. - \ 1990
Copenhagen etc. : Nordic Council of Ministers [etc.] (Miljoerapport 1990:14) - ISBN 9788773035016 - 124
bodemchemie - anorganische verbindingen - mineralen - bodem - stikstof - neerslag - chemische eigenschappen - zuurgraad - zure regen - modellen - onderzoek - normen - standaardisering - soil chemistry - inorganic compounds - minerals - soil - nitrogen - precipitation - chemical properties - acidity - acid rain - models - research - standards - standardization
Ammonia volatilization from arable land after surface application or incorporation of dairy cattle slurry
Faassen, H.G. van; Chardon, W.J. ; Bril, J. - \ 1990
Haren : Instituut voor Bodemvruchtbaarheid (Nota / Instituut voor Bodemvruchtbaarheid 236) - 83
dierlijke meststoffen - neerslag - chemische eigenschappen - zuurgraad - zure regen - luchtverontreiniging - geurstoffen - ammoniak - animal manures - precipitation - chemical properties - acidity - acid rain - air pollution - odours - ammonia
Het gebruik van onzekerheidsanalyse bij modelberekeningen : een toepassing op het regionale bodemverzuringsmodel RESAM
Kros, J. ; Janssen, P.H.M. ; Vries, W. de - \ 1990
Wageningen : Staring Centrum (Rapport / Staring Centrum 65) - 127
bodem ph - bodemaciditeit - bodemoplossing - fysicochemische eigenschappen - bodemeigenschappen - bodemchemie - neerslag - chemische eigenschappen - zuurgraad - zure regen - nederland - soil ph - soil acidity - soil solution - physicochemical properties - soil properties - soil chemistry - precipitation - chemical properties - acidity - acid rain - netherlands
Verbetering van de waterkwaliteit in het Groene Hart in het kader van een geintegreerd ruimtelijk beleid en milieubeleid (inventarisatiefase)
Wit, K.E. ; Heuvel, M.P.A. van den; Massop, H.T.L. - \ 1990
Wageningen : Staring Centrum (Rapport / Staring Centrum 97)
kanalen - chemische eigenschappen - ecologie - grondwater - hydrologie - landgebruik - nederland - ruimtelijke ordening - rivieren - kwel - waterlopen - oppervlaktewater - water - waterverontreiniging - waterkwaliteit - zonering - watergebruik - ecohydrologie - west-nederland - canals - chemical properties - ecology - groundwater - hydrology - land use - netherlands - physical planning - rivers - seepage - streams - surface water - water pollution - water quality - zoning - water use - ecohydrology - west netherlands
Vermindering van ammoniakemissie door korstvorming op rundveemengmest
Bode, M.J.C. de - \ 1990
Wageningen : IMAG (Rapport / Instituut voor Mechanisatie, Arbeid en Gebouwen nr. 226) - 41
opslagloodsen - mest - ammoniak - dierlijke meststoffen - drijfmest - neerslag - chemische eigenschappen - zuurgraad - zure regen - lucht - hygiëne - luchtverontreiniging - atmosfeer - milieu - rundveedrijfmest - stores - manures - ammonia - animal manures - slurries - precipitation - chemical properties - acidity - acid rain - air - hygiene - air pollution - atmosphere - environment - cattle slurry
Mestscheiding onder de roosters
Asseldonk, M. van; Voermans, J. - \ 1990
Praktijkonderzoek varkenshouderij 4 (1990)1. - ISSN 1382-0346 - p. 18 - 20.
varkens - neerslag - chemische eigenschappen - zuurgraad - zure regen - mestverwerking - pigs - precipitation - chemical properties - acidity - acid rain - manure treatment
Op het Proefstation voor de Varkenshouderij is gedurende een jaar het scheiden van mest onder de roosters bestudeerd. De mest werd gescheiden in een dikke en dunne fractie en dagelijks, met behulp van een mestschuif, uit de afdeling verwijderd.
Netto zuurbelasting van de bodem door atmosferische depositie
Loman, H. - \ 1989
Haren (Gr.) : IB (Nota / Instituut voor Bodemvruchtbaarheid 207) - 44
bodem ph - bodemaciditeit - bosschade - chemische precipitatie - luchtverontreiniging - zouten - depositie - neerslag - chemische eigenschappen - zuurgraad - zure regen - soil ph - soil acidity - forest damage - chemical precipitation - air pollution - salts - deposition - precipitation - chemical properties - acidity - acid rain
Ammonia volatilization from arable land after surface application or incorporation of cattle slurry : intermediate report of the period November 1988 - May 1989
Molen, J. van der; Faassen, H.G. van; Chardon, W.J. - \ 1989
Haren : Instituut voor Bodemvruchtbaarheid (Projectgroep Verzuringsonderzoek 36-15) - 32
dierlijke meststoffen - neerslag - chemische eigenschappen - zuurgraad - zure regen - luchtverontreiniging - geurstoffen - ammoniak - animal manures - precipitation - chemical properties - acidity - acid rain - air pollution - odours - ammonia
Beperking van de ammoniakemissie uit dierlijke mest : een verkenning van mogelijkheden en kosten
Oudendag, D.A. ; Wijnands, J.H.M. - \ 1989
Den Haag : LEI (Onderzoekverslag / Landbouw-Economisch Instituut, Afdeling Structuuronderzoek 56) - ISBN 9789052420455 - 72
dierlijke meststoffen - opslagloodsen - mest - drijfmest - lucht - hygiëne - luchtverontreiniging - atmosfeer - milieu - neerslag - chemische eigenschappen - zuurgraad - zure regen - ammoniak - duurzaamheid (sustainability) - natuurlijke hulpbronnen - hulpbronnengebruik - bescherming - herstel - kostenanalyse - nederland - animal manures - stores - manures - slurries - air - hygiene - air pollution - atmosphere - environment - precipitation - chemical properties - acidity - acid rain - ammonia - sustainability - natural resources - resource utilization - protection - rehabilitation - cost analysis - netherlands
Kwetsbaarheid van de Nederlandse bodem voor verzuring : een voorlopige indicatie in het kader van de Richtlijn Ammoniak en Veehouderij
Vries, W. de; Breeuwsma, A. ; Vries, F. de - \ 1989
Wageningen : Staring Centrum (Rapport / Staring Centrum 29) - 73
bodem ph - bodemaciditeit - cartografie - neerslag - chemische eigenschappen - zuurgraad - zure regen - nederland - luchtverontreiniging - ammoniak - emissie - vervluchtiging - thematische cartografie - soil ph - soil acidity - mapping - precipitation - chemical properties - acidity - acid rain - netherlands - air pollution - ammonia - emission - volatilization - thematic mapping
Lange-termijn effecten van verschillende depositiescenario's op representatieve bosbodems in Nederland
Vries, W. de; Kros, J. - \ 1989
Wageningen : Staring Centrum (Rapport / Staring Centrum 30) - 89
bosbouw - verzuring - bodem pH - bodemaciditeit - bodem - metaalelementen - zure gronden - kattekleigronden - neerslag - zure regen - zure depositie - aluminium - modellen - onderzoek - chemische eigenschappen - zuurgraad - Nederland - computersimulatie - simulatie - simulatiemodellen - forestry - acidification - soil pH - soil acidity - soil - metallic elements - acid soils - acid sulfate soils - precipitation - acid rain - acid deposition - models - research - chemical properties - acidity - Netherlands - computer simulation - simulation - simulation models
Om inzicht te krijgen in het lange-termijn effect van verschillende depositiescenario's op bosbodems zijn simulaties uitgevoerd gedurende een periode van 100 jaar met het regionale bodemverzuringsmodel RESAM, dat in het kader van het Nationaal Programma Zure Regen is ontwikkeld
Development of assays to quantify the immune response in cattle after administration of murine and bovine monoclonal antibodies = Ontwikkeling van testmethoden voor de kwantificering van immuunrespons in runderen na toediening van muize- en runder monoclonale antistoffen
Wissink, H.C.G. ; Veerhuis, R. ; Booman, P. - \ 1989
Zeist : IVO (Report / Instituut voor Veeteeltkundig Onderzoek "Schoonoord" B-339) - 31
antilichamen - rundvee - chemische samenstelling - chemische eigenschappen - immunoglobulinen - reticulo-endotheliaal systeem - antibodies - cattle - chemical composition - chemical properties - immunoglobulins - reticuloendothelial system
De reductie van de ammoniakemissie uit varkensmest na toediening op bouwland : in- en onderwerkmethoden en tijdstippen van de bewerking na de mesttoediening : mestsoorten van verschillende huisvestingssytemen
Bruins, M.A. ; Huijsmans, J.F.M. - \ 1989
Wageningen : IMAG (Rapport / Instituut voor Mechanisatie, Arbeid en Gebouwen nr. 225) - 27
dierlijke meststoffen - drijfmest - varkens - varkensstallen - lucht - hygiëne - luchtverontreiniging - atmosfeer - milieu - neerslag - chemische eigenschappen - zuurgraad - zure regen - ammoniak - opslagloodsen - mest - toedieningswijzen - bouwland - akkerbouw - animal manures - slurries - pigs - pig housing - air - hygiene - air pollution - atmosphere - environment - precipitation - chemical properties - acidity - acid rain - ammonia - stores - manures - application methods - arable land - arable farming
In het najaar van 1988 is in een Nederlands-Engelse samenwerking onderzoek verricht naar de mogelijkheden om de emissie uit varkensmest te beperken na toediening op bouwland.
Sensorisch en microbiologisch onderzoek van twintig monsters rundvlees
Mazijk-Bokslag, D.M. van; Cramwinckel, A.B. ; Herstel, H. - \ 1989
Wageningen : RIKILT (Rapport / RIKILT 89.44) - 23
rundvlees - kwaliteitscontroles - voedselinspectie - microbiologische technieken - sensorische wetenschappen - chemische eigenschappen - fysicochemische eigenschappen - beef - quality controls - food inspection - microbiological techniques - sensory sciences - chemical properties - physicochemical properties
In het kader van de sociale EG hulp is het wenselijk vlees aan te kunnen leveren in technische onderdelen (muis, dunne lende, etc.). Het vlees wordt bewaard in de vorm van voor- en achtervoeten. Het is daarom gewenst dat er op bepaalde tijdstippen naar behoefte geproportioneerd kan worden. Om dit mogelijk te maken zou het vlees eerst ontdooid moeten worden, waarna de technische onderdelen opnieuw ingevroren moeten worden. De vraag is nu in hoeverre de produkteigenschappen door opnieuw invriezen nadelig beïnvloed worden. Daarom zijn op verzoek van het Voedselvoorziening- en verkoopbureau (VIB) twintig monsters rundvlees sensorisch en microbiologisch onderzocht.
Eerste resultaten mestspoelsystemen
Asseldonk, M.M.L. van; Hoekstra, P. - \ 1989
Praktijkonderzoek varkenshouderij 3 (1989)6. - ISSN 1382-0346 - p. 9 - 11.
varkensstallen - opslagloodsen - drijfmest - vloeibare meststoffen - schoonmaakgereedschap - neerslag - chemische eigenschappen - zuurgraad - zure regen - pig housing - stores - slurries - liquid manures - cleaning equipment - precipitation - chemical properties - acidity - acid rain
De eerste voorlopige resultaten van de afdelingen met de mestspoelsystemen op het varkensproefbedrijf Sterksel zijn bekend. De cijfers wijzen op een belangrijke beperking van de ammoniakemissie ten opzichte van de traditionele opslag van mest onder deroosters.
Stalluchtzuivering bij mestvarkens
Asseldonk, M.M.L. van - \ 1989
Praktijkonderzoek varkenshouderij 3 (1989)5. - ISSN 1382-0346 - p. 24 - 25.
varkensstallen - afmesten - varkens - luchtverontreiniging - geurstoffen - atmosfeer - aërosolen - samenstelling - stof - luchtkwaliteit - neerslag - chemische eigenschappen - zuurgraad - zure regen - pig housing - finishing - pigs - air pollution - odours - atmosphere - aerosols - composition - dust - air quality - precipitation - chemical properties - acidity - acid rain
Op het Proefstation voor de Varkenshouderij is gedurende een jaar de stallucht van één mestvarkensafdeling met behulp van een biobed gezuiverd. Onder de op het Proefstation geldende omstandigheden werd voor de NH3- emissie een reductie van 85% en voorde emissie van stankstoffen een reductie van 75% bereikt.
Helpen lamellen tegen de uitstoot van ammoniak
Klooster, C.E. van 't; Bokma, S. - \ 1989
Praktijkonderzoek varkenshouderij 3 (1989)5. - ISSN 1382-0346 - p. 6 - 7.
varkensstallen - milieubeheersing - gebouwen - ventilatie - neerslag - chemische eigenschappen - zuurgraad - zure regen - lucht - hygiëne - luchtverontreiniging - ammoniak - pig housing - environmental control - buildings - ventilation - precipitation - chemical properties - acidity - acid rain - air - hygiene - air pollution - ammonia
Op het Proefstation worden ervaringen opgedaan met lamellen, die mogelijk de uitstoot van ammoniak uit de mestkelder verminderen, goedkoop zijn en in vrijwel iedere stal zijn in te passen. De plastic flappen scheiden de lucht in de put van die in stal.
Sulfur cycling in a Dutch moorland pool under elevated atmospheric S-deposition.
Feijtel, T.C.J. ; Salingar, Y. ; Hordijk, C.A. ; Sweerts, J.P.R.A. ; Breemen, N. van; Cappenberg, Th.E. - \ 1989
Water Air and Soil Pollution 44 (1989). - ISSN 0049-6979 - p. 215 - 234.
meren - reservoirs - plassen - water - waterverontreiniging - waterkwaliteit - eutrofiëring - zwavel - neerslag - chemische eigenschappen - zuurgraad - zure regen - lakes - ponds - water pollution - water quality - eutrophication - sulfur - precipitation - chemical properties - acidity - acid rain
Influence of airborne ammonium sulfate on soils of an oak woodland ecosystem in The Netherlands: Seasonal dynamics of solute fluxes.
Breemen, N. van; Boderie, P.M.A. ; Booltink, H.W.G. - \ 1989
In: Acid precipitation. Vol. 1. Case studies / Adriane, D.C., Havas, M., - p. 209 - 236.
bosbouw - bomen - bodem - stikstof - bodem ph - bodemaciditeit - neerslag - chemische eigenschappen - zuurgraad - zure regen - bodemvorming - bodemprofielen - zure depositie - forestry - trees - soil - nitrogen - soil ph - soil acidity - precipitation - chemical properties - acidity - acid rain - soil formation - soil profiles - acid deposition
The mechanism of NH3 and SO2 uptake by leaves and its physiological effects = [Het mechanisme van de NH3 en SO2 opname door bladeren en hierdoor veroorzaakte fysiologische effecten]
Hove, L.W.A. van - \ 1989
Agricultural University. Promotor(en): E.H. Adema; W.J. Vredenberg. - S.l. : Van Hove - 155
neerslag - chemische eigenschappen - zuurgraad - zure regen - oogstschade - luchtverontreiniging - zwaveldioxide - ammoniak - precipitation - chemical properties - acidity - acid rain - crop damage - air pollution - sulfur dioxide - ammonia
<p>The relation between uptake of atmospheric ammonia (NH <sub><font size="-2">3</font></sub> ) and sulphur dioxide (SO <sub><font size="-2">2</font></sub> ) by individual leaves, photosynthesis and stomatal conductance was examined. The experiments were carried out with bean plants ( <em>Phaseolus vulgaris L.</em> ) and poplar shoots ( <em>Populus euramericana L.</em> ). The method of analysis was derived from methods used in photosynthetic research. The uptake of NH <sub><font size="-2">3</font></sub> or SO <sub><font size="-2">2</font></sub> was experimentally determined by using a leaf chamber specially developed for this research. Simultaneously, transpiration and carbondioxide (CO <sub><font size="-2">2</font></sub> ) assimilation of leaves were measured.<p>The adsorption of NH <sub><font size="-2">3</font></sub> and SO <sub><font size="-2">2</font></sub> strongly increased with increasing air humidity, indicating a major role of water in the adsorption process. A descriptive model for the adsorption in the cuticle-watersystem is proposed. The affinity of SO <sub><font size="-2">2</font></sub> for the leaf surface was found to be approximately twice that of NH <sub><font size="-2">3</font></sub> . A mixture of these gases in the air mutually stimulated their adsorption on the leaf surface. No significant desorption or transport of these gases through the cuticle could be detected.<p>The uptake of NH <sub><font size="-2">3</font></sub> into leaves appeared to be dependent on the leaf boundary layer and stomatal resistance and NH <sub><font size="-2">3</font></sub> concentration at the leaf surface. In contrast, a less clear relation between SO <sub><font size="-2">2</font></sub> uptake and stomatal resistance was found, in particular at a low vapor pressure deficit (VPD). The measured flux was larger than can be calculated from the boundary layer and stomatal resistance for H <sub><font size="-2">2</font></sub> O, suggesting a lower resistance of the diffusion pathway. The same was observed for NH <sub><font size="-2">3</font></sub> at a low temperature and VPD. It is postulated that this discrepancy is due to a difference in path length.<p>Under the conditions of the present research the physiological effects caused by a prolonged exposure to NH <sub><font size="-2">3</font></sub> or SO <sub><font size="-2">2</font></sub> became notable at concentrations of about 100 μg.m <sup><font size="-2">-3</font></SUP>. The NH <sub><font size="-2">3</font></sub> exposure had a positive effect on photosynthesis, stomatal conductance and NH <sub><font size="-2">3</font></sub> uptake, whereas a small irreversible inhibition of photosynthesis and stomatal conductance was induced by the SO <sub><font size="-2">2</font></sub> exposure.<p>The relations assessed in this study can be used to construct a descriptive model for NH <sub><font size="-2">3</font></sub> and SO <sub><font size="-2">2</font></sub> transfer into leaves as a function of wind velocity, light intensity, air temperature and humidity.
Systeemanalyse en beleidsscenario's verzuringsproblematiek in de Landbouw. Discussienota t.b.v. referentenbijeenkomsten in april-mei 1989 in het kader van het project Systeemanalyse van de Nederlandse Landbouw (SAL).
Bovy, M.W.L. ; Knol, O.M. ; Nijland, G.O. ; Stallen, P.J. ; Verberne, F.C.M. - \ 1989
Amsterdam [etc.] : IMSA [etc.] - 36
neerslag - chemische eigenschappen - zuurgraad - zure regen - landbouw - overheidsbeleid - milieubeleid - milieuwetgeving - luchtverontreiniging - bodemverontreiniging - waterverontreiniging - systeemanalyse - onderzoek - analyse - computersimulatie - simulatie - simulatiemodellen - nederland - precipitation - chemical properties - acidity - acid rain - agriculture - government policy - environmental policy - environmental legislation - air pollution - soil pollution - water pollution - systems analysis - research - analysis - computer simulation - simulation - simulation models - netherlands
De betekenis van de chemische samenstelling van het grondwater voor het milieu van wilde planten
Kemmers, R.H. ; Wirdum, G. van - \ 1988
Biovisie magazine (1988)2. - ISSN 0921-9242 - p. 12 - 16.
chemische eigenschappen - ecologie - milieu - grondwater - hydrologie - plantenecologie - synecologie - vegetatie - ecohydrologie - geohydrologie - hydrogeologie - chemical properties - ecology - environment - groundwater - hydrology - plant ecology - synecology - vegetation - ecohydrology - geohydrology - hydrogeology
Tijdreeksen van gegevens over chemie en diatomeeen uit enige verzuurde vennen
Dam, H. van; Mertens, A. - \ 1988
Leersum : RIN (Intern rapport / Rijksinstituut voor Natuurbeheer 88/47) - 25
bacillariophyta - fytoplankton - zoet water - neerslag - chemische eigenschappen - zuurgraad - zure regen - stilstaand water - nederland - veluwe - gelderland - phytoplankton - fresh water - precipitation - chemical properties - acidity - acid rain - standing water - netherlands
Hydrochemistry of rich fen and water management
Kemmers, R.H. ; Jansen, P.C. - \ 1988
Agricultural Water Management 14 (1988)1/4. - ISSN 0378-3774 - p. 399 - 412.
calcium - carbonaten - chemische eigenschappen - grondwater - bedrijfsvoering - natuurbescherming - nederland - beleid - bodemwaterbalans - stilstaand water - waterbeheer - watervoorraden - hydrologie - carbonates - chemical properties - groundwater - management - nature conservation - netherlands - policy - soil water balance - standing water - water management - water resources - hydrology
Aanpak, structuur en voorlopige procesbeschrijving van een bodemverzuringsmodel voor toepassing op regionale schaal
Vries, W. de; Waltmans, M.J.P.H. ; Versendaal, R. van - \ 1988
Wageningen : STIBOKA (Rapport / Stichting voor Bodemkartering nr. 2014) - 132
neerslag - chemische eigenschappen - zuurgraad - zure regen - zure gronden - kattekleigronden - bodem ph - bodemaciditeit - modellen - onderzoek - precipitation - chemical properties - acidity - acid rain - acid soils - acid sulfate soils - soil ph - soil acidity - models - research
Het rapport beschrijft de opzet van een voorlopig bodemverzuringsmodel, waarin de meeste zuurproducerende en zuurverbruikende processen zijn opgenomen. Het accent ligt op de aanpak van het bodemverzuringsmodel in relatie tot de specifieke problemen die optreden bij toepassing op regionale schaal. Wat de aanpak betreft wordt ingegaan op de afbakening van het te modelleren systeem, de gekozen modelstructuur en de voorlopige modelformulering. M.b.t. de toepassing ligt de nadruk op het probleem van data-invoer en het gebruik van geografische informatiesystemen
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