Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    '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.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Current refinement(s):

Records 1 - 20 / 31

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: keywords==ion exchange
Check title to add to marked list
Microbial electrosynthesis of biochemicals : innovations on biocatalysts, electrodes and ion-exchange for CO2 supply, chemicals production and separation
Bajracharya, S. - \ 2016
Wageningen University. Promotor(en): Cees Buisman; David Strik; Deepak Pant. - Wageningen : Wageningen University - ISBN 9789462578531 - 181
carbon dioxide - biofuels - chemicals - biocatalysis - ion exchange - electrodes - kooldioxide - biobrandstoffen - chemicaliën - biokatalyse - ionenuitwisseling - elektrodes

Microbial electrosynthesis (MES) is an electricity-driven production of chemicals from low-value waste using microorganisms as biocatalysts. MES from CO2 comprises conversion of CO2 to multi-carbon compounds employing microbes at the cathode which use electricity as an energy source. This thesis presents innovations on MES from CO2 using anaerobic mixed-cultures, circumventing the methane generation. Acetate was the primary product but other products including ethanol, butyrate were also produced. Establishment of active biocathode at the graphite felt cathode was achieved under long-term operation which led to the acetate accumulation up to 7-10 g L-1 at -1 V/Ag/AgCl cathode potential. CO2 reduction in MES requires continuous availability of CO2 and low cathode potential to ensure the supply of reducing equivalents/hydrogen. Use of gas diffusion biocathode doubled the CO2 mass-transfer rate which enhanced the production rates, reaching. Furthermore, a sustainable technology for manufacturing biochemicals/biofuels was demonstrated in this thesis by integrating the product separation in MES. The electricity-driven production of chemicals/biofuels from CO2/waste products and subsequent product recovery studies prospect an integration of microbial electrosynthesis with biorefineries for the up-scaling of both technologies.

Nieuwe ionenwisselaar verwijdert 98% van nitraat uit spuiwater : door terugwinnen stikstof voldoen aan lozingsnormen
Ruijven, Jim van - \ 2016
horticulture - greenhouse horticulture - water management - drainage water - ion exchange - ion exchange treatment - technology - agricultural research - nitrogen - sodium - minerals - ion exchange resins - standards - eu regulations

Door nitraat te verwijderen uit spuiwater, kun je voldoen aan de lozingsregels voor 2027. Die zijn immers geënt op stikstofnormen. De teler zou echter nog meer hebben aan verwijdering van natrium, omdat hij dan langer kan recirculeren. Een nieuwe techniek, afkomstig uit Zuid-Afrika, biedt op beide vlakken veel perspectieven.

Resistance identification and rational process design in Capacitive Deionization
Dykstra, Jouke ; Zhao, R. ; Biesheuvel, P.M. ; Wal, A. van der - \ 2016
Water Research 88 (2016). - ISSN 0043-1354 - p. 358 - 370.
ionentransport - weerstand - waterzuivering - ontzilting - elektrodes - ionenuitwisseling - specifieke ionenelektrodes - ion transport - resistance - water treatment - desalination - electrodes - ion exchange - specific ion electrodes
Capacitive Deionization (CDI) is an electrochemical method for water desalination employing porous carbon electrodes. To enhance the performance of CDI, identification of electronic and ionic resistances in the CDI cell is important. In this work, we outline a method to identify these resistances. We illustrate our method by calculating the resistances in a CDI cell with membranes (MCDI) and by using this knowledge to improve the cell design. To identify the resistances, we derive a full-scale MCDI model. This model is validated against experimental data and used to calculate the ionic resistances across the MCDI cell. We present a novel way to measure the electronic resistances in a CDI cell, as well as the spacer channel thickness and porosity after assembly of the MCDI cell. We identify that for inflow salt concentrations of 20 mM the resistance is mainly located in the spacer channel and the external electrical circuit, not in the electrodes. Based on these findings, we show that the carbon electrode thickness can be increased without significantly increasing the energy consumption per mol salt removed, which has the advantage that the desalination time can be lengthened significantly.
Theory and operation of capacitive deionization systems
Zhao, R. - \ 2013
Wageningen University. Promotor(en): Bert van der Wal, co-promotor(en): Huub Rijnaarts; Maarten Biesheuvel. - S.l. : s.n. - ISBN 9789461736390 - 155
waterzuivering - drinkwater - ontzilting - elektrodes - membranen - ionenuitwisseling - water treatment - drinking water - desalination - electrodes - membranes - ion exchange
On the origin of nitrous oxide and its oxygen
Kool, D.M. - \ 2010
Wageningen University. Promotor(en): Oene Oenema; Jan-Willem van Groenigen; N. Wrage. - [S.l.] : S.n. - ISBN 9789085856948 - 199
distikstofmonoxide - bodem - denitrificatie - isotopenlabelling - zuurstof - ionenuitwisseling - methodologie - kringlopen - nitrous oxide - soil - denitrification - isotope labeling - oxygen - ion exchange - methodology - cycling
Lachgas (N2O) is een broeikasgas dat bijdraagt aan de opwarming van de aarde en de afbraak van ozon in de stratosfeer. Om emissies van N2O terug te dringen zullen we moeten begrijpen hoe en waar het ontstaat. Er is echter veel onduidelijkheid over de verschillende manieren waarop N2O wordt gevormd, en hoe deze processen worden beïnvloed door de omgeving. Wereldwijd vormen bodems de grootste bron van lachgas naar de atmosfeer. Met mijn onderzoek probeer ik daarom een beter inzicht te krijgen in de productie van N2O in bodems. Mijn hoofddoel was om de bijdrage van ‘nitrifier denitrification’ als afzonderlijk proces te bestuderen. In dit proces wordt nitriet (NO2-) omgezet in N2O door ammonia oxiderende bacteriën (AOB), die normaliter juist NO2- vormen vanuit ammonia (NH3). Het reducerende proces tot N2O wordt normaal gesproken voornamelijk toegeschreven aan andere organismen, de denitrificeerders.
Ion speciation in milk-like systems
Gao, R. - \ 2010
Wageningen University. Promotor(en): Tiny van Boekel, co-promotor(en): Herman van Leeuwen. - [S.l. : S.n. - ISBN 9789085857228 - 250
melkproducten - ionenbalans - ionen - ionenuitwisseling - wiskundige modellen - milk products - ion balance - ions - ion exchange - mathematical models
The research described in this thesis is about ion behaviour in milk systems as a function of changing conditions (pH, ionic strength, addition of electrolytes and non-electrolytes). The focus was on (i) quantification of the ion equilibria in milk systems based on experimental conditions, (ii) development of quantitative models describing the ion equilibria. The so-called Donnan Membrane Technique (DMT) was successfully applied to determine the concentrations of free Ca2+, Mg2+, Na+ and K+ ions in milk-like systems. Next, models were developed to describe ion equilibria in simulated milk ultrafiltrate solution (SMUF) as a first step to build models for milk systems. Freshly prepared SMUF appeared not to be in thermodynamic equilibrium regarding the supersaturation of calcium phosphate. Therefore, the equilibrium ion speciation (EIS) model and the dynamic ion speciation (DIS) model were developed for SMUF at equilibrium and at initial state, respectively. Both EIS and DIS models gave satisfactory predictions in ion equilibria in SMUF enriched with different electrolytes. Also, addition of non-electrolytes such as various disaccharides appeared to remarkably increase the Ca2+ and H+ ion activities in SMUF and milk. The observed results could be explained by a theory called Mean Spherical Approximation (MSA), which suggests that excluded volume effects due to addition of sugars account for the increase in Ca2+ and H+ ion activity coefficients and thus on Ca2+ and H+ ion activities. Based on the EIS and DIS models, a model named Milk Ion Speciation (MIS) was built to describe ion equilibria in milk. The MIS model was able to predict the ion composition in milk and milk enriched with different electrolytes. In addition, the methodologies of Ca2+ activity measurement were reviewed. We found that the calcium ion selective electrode (Ca-ISE) underestimated the Ca2+ activity at ionic strength lower than 0.1 mol/kg water compared to DMT. It appeared that the ionic composition of conventional calibration standards significantly affects the Ca ion activity measurement. A series of new calibration standards, having similar composition to milk serum, was developed and this remarkably improved the Ca2+ activity measurement in milk-like systems. The developed ion speciation models were carefully evaluated. Particularly, the current limitations of the models such as the nature of CCP and the effect of adding polyphosphate were intensively discussed. Moreover, the models were tested to calculate ion composition in cheese. It turns out that the models offer great potential to correlate ion properties with the functional properties of dairy products.

Terugwinnen van nutriënten uit zwart water vanuit een Nederlands perspectief
Voorthuizen, E.M. van; Zwijnenburg, A. ; Meer, W. van der; Temmink, H. - \ 2008
Afvalwaterwetenschap 7 (2008)3. - ISSN 1569-2361 - p. 160 - 168.
voedingsstoffen - afvalwater - terugwinning - elektrodialyse - omgekeerde osmose - ionenuitwisseling - biologische behandeling - afvalwaterbehandeling - fosfaten - stikstof - nutrients - waste water - recovery - electrodialysis - reverse osmosis - ion exchange - biological treatment - waste water treatment - phosphates - nitrogen
Dit artikel gaat nader in op de terugwinning van nutriënten uit het zwarte (toilet) water. Tegelijkertijd moet hierbij rekening worden gehouden met de twee andere doelen van sanitatie: de bescherming van de publieke gezondheid en het milieu. Bescherming van het milieu betekent in Nederland in principe dat voldaan moet worden aan de lozingseisen voor stikstof van 10 mg N l(-1) en fosfaat van 1 mg P l(-1)
Vermindering van de ammoniakemissie door een chemische luchtwasser
Scholten, R.H.J. ; Plagge, J.G. ; Peet-Schwering, C.M.C. van der - \ 1997
Rosmalen : Praktijkonderzoek varkenshouderij (Proefverslag / Praktijkonderzoek Varkenshouderij P1.178) - 20
luchtverontreiniging - ammoniak - emissie - vervluchtiging - gassen - filtratie - zuiveren - biologische filtratie - analytische methoden - scheiding - ionenuitwisseling - varkensstallen - ammoniakemissie - air pollution - ammonia - emission - volatilization - gases - filtration - purification - biological filtration - analytical methods - separation - ion exchange - pig housing - ammonia emission
Het Praktijkonderzoek Varkenshouderij heeft in opdracht van Bovema Konstrukties B.V. uit Milsbeek de chemische luchtwasser als methode voor het reduceren van de ammoniakemissie uit varkensstallen onderzocht. Naast het onderzoek naar de procentuele emissiereductie bij toepassing van chemische luchtwassers zijn enkele praktische vragen onderzocht, te weten: Hoe storingsgevoelig is het proces? Hoeveel zuur en energie wordt verbruikt? Hoe groot is de toename van de jaarkosten?
Ammoniakemissie en kosten bij een chemische luchtwasser
Verdoes, N. ; Vrielink, M. - \ 1997
Praktijkonderzoek varkenshouderij 11 (1997)4. - ISSN 1382-0346 - p. 21 - 23.
luchtverontreiniging - ammoniak - emissie - vervluchtiging - varkens - varkensstallen - gassen - filtratie - zuiveren - biologische filtratie - analytische methoden - scheiding - ionenuitwisseling - kostenanalyse - air pollution - ammonia - emission - volatilization - pigs - pig housing - gases - filtration - purification - biological filtration - analytical methods - separation - ion exchange - cost analysis
Het Praktijkonderzoek Varkenshouderij onderzocht gedurende één mestronde een chemische luchtwasser op de reductie van de ammoniakemissie uit een vleesvarkensstal. De ammoniakemissie werd met ruim 90% gereduceerd.
Gescheiden afvoer van vaste mest en urine in combinatie met spoelen
Elst-Wahle, L. ter; Brok, G. den - \ 1995
Praktijkonderzoek varkenshouderij 9 (1995)6. - ISSN 1382-0346 - p. 19 - 21.
luchtverontreiniging - ammoniak - analytische methoden - dierlijke meststoffen - rundveedrijfmest - emissie - ionenuitwisseling - vloeibare meststoffen - mest - varkens - zuiveren - scheiding - drijfmest - vervluchtiging - mestoverschotten - mestverwerking - air pollution - ammonia - analytical methods - animal manures - cattle slurry - emission - ion exchange - liquid manures - manures - pigs - purification - separation - slurries - volatilization - manure surpluses - manure treatment
Gescheiden afvoer van vaste mest en urine uit de stal leidt tot een vermindering van de ammoniakemissie. In een onderzoek van het Praktijkonderzoek Varkenshouderij leidde een dergelijke mestafvoer in combinatie met spoelen en een daarop volgende mestscheiding tot technische problemen.
Ammonium acetate extraction for soil heavy metal speciation; model aided soil test interpretation
Castilho, P. del; Rix, I. - \ 1993
International Journal of Environmental Analytical Chemistry 51 (1993). - ISSN 0306-7319 - p. 59 - 64.
ionenuitwisseling - ammoniumzouten - zware metalen - chemische speciatie - grondanalyse - bodemoplossing - ion exchange - ammonium salts - heavy metals - chemical speciation - soil analysis - soil solution
Proton sinks in soil controlling soil acidification.
Bruggenwert, M.G.M. ; Hiemstra, T. ; Bolt, G.H. - \ 1991
In: Soil acidity / Ulrich, B., Sumner, M.E., - p. 8 - 27.
zure gronden - kattekleigronden - bodem - bodemkunde - ionenuitwisseling - acid soils - acid sulfate soils - soil - soil science - ion exchange
Vastlegging en transport van fosfaat in zandkolommen.
Leus, F.M.R. ; Louer, M.J.P.F. ; Zee, S.E.A.T.M. van der - \ 1989
Wageningen : LU - 80
derivaten - ionenuitwisseling - permeabiliteit - fosfaten - fosfor - fosforpentoxide - bodem - bodemkunde - bodemtextuur - bodemtypen - derivatives - ion exchange - permeability - phosphates - phosphorus - phosphorus pentoxide - soil - soil science - soil texture - soil types
Weer, klimaat en bodem : voordrachten gehouden op de Contactdagen 1987 van het technisch - bodemkundig personeel van de Stichting voor Bodemkartering
Bouma, J. ; Bouten, W. ; Kroon, L.J.M. - \ 1988
Wageningen : STIBOKA - 112
agrometeorologie - bodem - bodemkunde - ionenuitwisseling - bodemvorming - verwering - landschap - klimaat - overstromingen - klimatologie - agricultural meteorology - soil - soil science - ion exchange - soil formation - weathering - landscape - climate - floods - climatology
Combined ion exchange / biological denitrification for nitrate removal from ground water
Hoek, J.P. van der - \ 1988
Agricultural University. Promotor(en): L. Lijklema; A. Klapwijk. - S.l. : van der Hoek - 97
verontreinigingsbeheersing - grondwaterverontreiniging - rioolwater - afvalwater - nitraten - verwijdering - ionenuitwisseling - denitrificatie - pollution control - groundwater pollution - sewage - waste water - nitrates - removal - ion exchange - denitrification

This thesis deals with the development of a new process for nitrate removal from ground water. High nitrate concentrations in ground water are a result of fertilization in agriculture. According to a directive of the European Community the maximum admissible concentration of nitrate in drinking water is 11.3 mg NO 3--N/l and the guide level is 5.6 mg NO 3--N/l. To supply water that meets this standard several water supply companies will have to remove nitrate from ground water. Two existing techniques, viz ion exchange and biological denitrification, have serious disadvantages when used separately. Therefore, a new process has been developed that consists of a combination of ion exchange and biological denitrification. In this process nitrate is removed from the ground water by ion exchange. The ion exchange resins are regenerated in a closed circuit through an upflow sludge blanket (USB) denitrification reactor. In this reactor denitrifying bacteria remove nitrate from the regenerant, so that it can be used again and has not to be disposed of. As compared with conventional regeneration of anion exchange resins regeneration salt requirement and brine production are minimized. Further, in contrast with traditional single denitrification procedures, there is no direct contact between ground water and denitrifying bacteria.

The first part of this thesis deals with the effect of high salt concentrations, as present in the closed regeneration system, on biological denitrification. Concentrations up to 30 g NaHCO 3 /l or 30 g NaCl/l have only little effect on the activity of denitrifying sludge. With high NaHCO 3 concentrations the sludge yield coefficient decreases and nitrite accumulation is suppressed. High sulfate concentrations (5.5 9 SO 42-/l) do not result in sulfide production in an USB denitrification reactor fed with methanol, when methanol is added in an appropriate ratio to the amount of nitrate to be denitrified.

The second part of this thesis deals with the ion exchange part of the combined process. Regeneration of anion exchange resins can be achieved with a solution containing 30 g NaHCO 3 /l provided that a larger flow rate and a longer regeneration time are used as compared with conventional regeneration procedures. With nitrate selective resins it is possible to remove nitrate from ground water that contains high sulfate concentrations, while the nitrate capacity of these resins is not affected by high sulfate concentrations in the regenerant. To safeguard the bacteriological drinking water quality the resins have to be disinfected after each regeneration cycle by rinsing with 0.075% peracetic acid for 15 minutes or by rinsing with 0.20% hydrogen peroxide for 45 minutes. Since the first possibility results in an important loss of resin capacity on the long term, only the latter can be applied in practice.

The third part of this thesis deals with the operation of a lab-scale pilot plant. The most important process variables studied were the regenerant composition (NaCl or NaHCO 3 ), the ion exchange resin type (sulfate selective or nitrate selective) and the ground water composition (low sulfate concentration or high sulfate concentration). To explain some phenomena that were observed during this research a computer model has been developed. With this model the regeneration of anion exchange resins in a closed circuit can be optimized.

Vulnerability in relation to physico-chemical compound behaviour and spatially variable soil properties.
Zee, S.E.A.T.M. van der; Riemsdijk, W.H. van; Lexmond, Th.M. ; Haan, F.A.M. de - \ 1987
In: Vulnerability of soil and groundwater to pollutants : international conference Noordwijk aan Zee, The Netherlands, March 30 - April 3, 1987 / van Duijvenbooden, W., van Waegeningh, H.G., - p. 515 - 526.
ionenuitwisseling - uitspoelen - bodem - bodemkunde - bodemkarteringen - ion exchange - leaching - soil - soil science - soil surveys
Onderzoek naar de effecten van wateraanvoer en peilveranderingen in agrarische gebieden op de waterkwaliteit in natuurgebieden. Dl. 4: Enkele hydrologische, bodemfysische en bodemchemische parameters uit twee SWNBL proefgebieden
Hendriks, R.F.A. - \ 1986
Wageningen : ICW (Nota / Instituut voor Cultuurtechniek en Waterhuishouding 1743) - 37
bodemwater - bodemchemie - ionenuitwisseling - ecologie - hydrologie - ecohydrologie - wateraanvoer - peilbeheer - natuurgebieden - soil water - soil chemistry - ion exchange - ecology - hydrology - ecohydrology - water advance - water level management - natural areas
In het kader van de Studiecommissie Waterbeheer, Natuur, Bos en Landschap (SWNBL) verricht het ICW onderzoek naar de effecten van wateraanvoer en peilveranderingen in agrarische gebieden op de waterkwaliteit in natuurgebieden. In deze nota worden de resultaten van een aantal deelonderzoeken van dit velden laboratoriumonderzoek gegeven. Het betreft enkele bodemfysische en bodemchemische eigenschappen van de proefgebieden. De betreffende proefgebieden zijn de Empese en Tondense heide in de ruilverkaveling Brummen-Voorst en het boezemland Veerstalblok in de polder Stolwijk, ten zuiden van Gouda.
Formulation of a model describing the weathering process of CaCO3 in soils
Ritsema, C.J. - \ 1986
Wageningen : ICW (Nota / Instituut voor Cultuurtechniek en Waterhuishouding 1713) - 46
calcium - chemische eigenschappen - ionenuitwisseling - fysicochemische eigenschappen - bodemchemie - bodemvorming - verwering - chemical properties - ion exchange - physicochemical properties - soil chemistry - soil formation - weathering
The weathering of CaCO3 is given in a new equation
Formulas for activity coefficients of individual ions
Ritsema, C.J. ; Bloemer, F. - \ 1986
Wageningen : I.C.W. (Nota / Instituut voor Cultuurtechniek en Waterhuishouding 1732) - 34
bodemchemie - ionenuitwisseling - soil chemistry - ion exchange
For chemical calculations with gaseous equilibria and for non-ionic reactions in solution one can calculate in terms of concentrations to a fairly good approximation. However, in dealing with ionic reactions, with certain aspects of kinetics in solution, and with elcetromotive force studies, substitutiion of concentrations for activities is frequently not possible. For this reason it is essential to consider how ionic concentrations can be converted to activities
A review of the oxidation and reduction processes in acid sulphate soils
Ngoc Sen, L. - \ 1985
Wageningen : ICW (Nota / Instituut voor Cultuurtechniek en Waterhuishouding no. 1613) - 26
zure gronden - kattekleigronden - bodem - bodemkunde - ionenuitwisseling - acid soils - acid sulfate soils - soil - soil science - ion exchange
Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.