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.

    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.

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Stof tot nadenken : vier manieren om de mode-industrie duurzamer te maken
Louwerens, Tessa ; Poldner, Kim ; Fischer, Arnout ; Broek, Ben van den; Dam, Jan van; Houthoff, Iris - \ 2018
biobased materials - clothing - fibres - algae - biomass - hemp - dyes - pigments - bioplastics - biopolymers - ink - natural products
Mid season sale, twee halen één betalen, op=op. Mode wordt steeds goedkoper en wisselt steeds sneller. Leuk voor het oog, maar achter al die fashion gaat grote milieuschade schuil. WUR-wetenschappers zoeken naar manieren om de kledingindustrie duurzamer te maken. Van hennepstof tot algenverf, van chemisch recyclen tot vintage kleding.
Christiaan Bolck (Biobased Performance Materials): ‘We doen onderzoek dat impact heeft’
Bolck, Christiaan - \ 2018
biobased economy - biobased materials - biomass - polymers - bioplastics - dyes - pigments - paints - plant extracts
'Productie van rode algen kan winstgevend zijn' : Wim Voogt over onderzoek algenteelt
Voogt, Wim - \ 2015
algae - algae culture - greenhouse horticulture - dyes - antioxidants - cropping systems - biobased economy - biobased chemicals

De algenteelt in een gesloten systeem in de kas is dusdanig intensief en kostbaar dat het ook een hoogwaardig product moet opleveren. De rode algen die in 2015 zijn gekweekt bij Wageningen UR Glastuinbouw voldoen daaraan. Ze bevatten een gewilde kleurstof die bovendien een krachtige antioxidant is. Dat kan op termijn goede inkomsten opleveren.

High-performance inhoudsstoffen vinden hun weg naar de markt
Meer, I.M. van der; Vollebregt, M. - \ 2015
Kennis & Innovatie (2015)3. - p. 2 - 4.
biobased economy - materialen uit biologische grondstoffen - chemicaliën uit biologische grondstoffen - plantextracten - rubber - reststromen - kleurstoffen (dyes) - plantaardige pesticiden - innovaties - biobased materials - biobased chemicals - plant extracts - residual streams - dyes - botanical pesticides - innovations
High-performance inhoudsstoffen uit biomassa ontstijgen de onderzoekslaboratoria en duiken op in proefprojecten met bedrijven en concrete toepassingen in eindproducten. Het tempo waarmee dit gebeurt en de onderliggende markt drivers verschillen per productgebied, zo blijkt uit een rondje langs biobased projecten op het gebied van kleurstoffen, farmaceutische producten/functional foods, gewasbescherming en natuurrubber.
Use of methylene blue uptake for assessing cell viability of colony-forming microalgae
Lemos Bicas, J. ; Kleinegris, D.M.M. ; Barbosa, M.J. - \ 2015
Algal Research 8 (2015). - ISSN 2211-9264 - p. 174 - 180.
botryococcus-braunii - yeast cells - race-b - biomass - hydrocarbons - extraction - chemicals - dyes
During the past few years, interest in microalgae has grown, mainly because of their potential for biofuel production. Botryococcus braunii, a green microalga that can accumulate more than half of its dry weight as hydrocarbons, is one of the most important examples. This microorganism grows in colonies and there has been no reliable viability protocol reported for this species as yet. Knowing the number of dead cells in cultures is essential for the development of efficient bioprocesses such as non-destructive extraction procedures (“milking”) to obtain lipid soluble substances from microalgal biomass. Our study presents a simple colorimetric method to determine the proportion of living to dead cells in cultures, based on the uptake of methylene blue in solution by dead B. braunii cells. The main parameters influencing this process were investigated and used to develop a protocol. This technique was validated using flow cytometry and Neochloris oleoabundans, and appears not to be limited to use with B. braunii.
Horti Indigo for denim : haalbaarheidsstudie en marktontwikkeling
Lans, C.J.M. van der; Noort, F.R. van; Garcia Victoria, N. - \ 2014
Bleiswijk : Wageningen UR Glastuinbouw'Kenniscentrum Plantenstoffen (Rapport / Wageningen UR Glastuinbouw 1317) - 38
glastuinbouw - kleurstoffen (dyes) - verfplanten - indigofera tinctoria - haalbaarheidsstudies - nederland - greenhouse horticulture - dyes - dye plants - feasibility studies - netherlands
The (sub) tropical plant Indigofera is grown for use as indigo dye. This feasibility study focused at the technical and economic potential of sustainable greenhouse cultivation of Indigofera. Outdoor cultivation (Asia) produces 30.87-76.72 kg dye/ha. Yield enhancing factors are cultivar, plant stage at harvest, light color during cultivation, day length, plant density, fertilization (N, P), CO2 gift, and hydroponic cultivation. Market price for natural indigo is around 35 euro/kg (6-10 times higher than synthetic indigo). Higher market prices seem possible. The worldwide growing interest for natural, sustainable textile fibres and dyes shows market opportunities. The textile industry is aware that current indigo cultivation in Asia is not very sustainable. Two greenhouse cultivation variants were calculated: ‘high-tech’ greenhouse cultivation (heated, intense cultivation) and ‘mid-tech’ greenhouse cultivation (container plants, non-heated cultivation). Estimated costs of ‘ high-tech ‘ greenhouse cultivation indigo are 63 €/m2 per year and for ‘mid-tech ‘ greenhouse cultivation 43 €/m2. With current market prices and content levels a leaf production of 10.217 kg/m2/year (hig-tech cultivation) or 7.016 kg/m2/year (mid-tech cultivation) is necessary. When indigo content can be increased through specific cultivation measures, or significant higher prices than the reported market prices can be realized, a business case ‘horti indigo’ will become feasible. Crucial is commitment from buyers for high market prices and buying amounts.
Spectrophotometric comparison of the content of chlorophylls in weld (Reseda luteola)
Villela, A. ; Derksen, G.C.H. ; Zuilhof, H. ; Beek, T.A. van - \ 2011
Analytical Methods 3 (2011)6. - ISSN 1759-9660 - p. 1424 - 1427.
plant - dyes
An analytical method for the comparison of the content of chlorophylls and their structurally similar breakdown products in weld is described
Thermophillic treatment by anaerobic granular sludge as an effective approach to accelerate the electron transfer and improve the reductive decolorization of azo dyes in bioreactors
Santos, A.B. dos; Traverse, J. ; Cervantes, F.J. ; Lier, J.B. van - \ 2005
Water Science and Technology 52 (2005)1-2. - ISSN 0273-1223 - p. 363 - 369.
ontkleuring - temperatuur - textielindustrie - kleurstoffen (dyes) - azoverbindingen - afvalwaterbehandeling - anaërobe behandeling - slib - decolorization - temperature - textile industry - dyes - azo compounds - waste water treatment - anaerobic treatment - sludges - redox mediators - reactor - transformation - aqds
The effects of temperature, hydraulic retention time (HRT), and the redox mediator, thraquinone- 2,6-disulfonate (AQDS), on electron transfer and subsequent reductive decolorization of dyes rom textile wastewater was assessed in mesophilic and thermophilic anaerobic bioreactors. The results clearly show that compared to mesophilic anaerobic treatment, thermophilic treatment at 55 8C is an effective approach for increasing the electron transfer capacity in bioreactors, and thus improving the decolorization rates. At an HRT of 2.5 h and in the absence of AQDS, the color removal was 5.3-fold higher at 55 8C compared to 30 8C. Furthermore, similar decolorizations were found at 55 8C between the AQDS-free and AQDSsupplemented reactors, whereas a significant difference (up to 3.6-fold) on dye reduction occurred at 30 8C. Keywords Azo dye; color removal; electron transfer; anaerobic treatment; mesophilic; thermophilic
Reductive decolourisation of azo dyes by mesophilic and thermophilic methanogenic consortia
Cervantes, F.J. ; Santos, A.B. dos; Madrid, M.P. de; Stams, A.J.M. ; Lier, J.B. van - \ 2005
Water Science and Technology 52 (2005)1-2. - ISSN 0273-1223 - p. 351 - 356.
slib - ontkleuring - azoverbindingen - kleurstoffen (dyes) - anaërobe behandeling - redoxreacties - microbiële afbraak - afvalwaterbehandeling - sludges - decolorization - azo compounds - dyes - anaerobic treatment - redox reactions - microbial degradation - waste water treatment - anaerobic sludge - redox mediators - quinone-respiration - anthraquinone dyes - granular sludge - transformation - toxicity - bioreactors - inhibition - reactor
The contribution of acidogenic bacteria and methanogenic archaea on the reductive decolourisation of azo dyes was assessed in anaerobic granular sludge. Acidogenic bacteria appeared to play an important role in the decolourising processes when glucose was provided as an electron donor; whereas methanogenic archaea showed a minor role when this substrate was supplemented in excess. In the presence of the methanogenic substrates acetate, methanol, hydrogen and formate, methane production became important only after colour was totally removed from the batch assays. This retardation in methane production may be due to either a toxic effect imposed by the azo dyes or to the competitive behaviour of azo dyes to the methanogenic consortia for the available reducing equivalents. Keywords Azo dyes; decolourisation; methanogenic consortium; redox mediator; inhibitors
Reductive Decouloristation of Dyes by Thermophilic Anaerobic Granular Sludge
Bezerra Dos Santos, A. - \ 2005
Wageningen University. Promotor(en): Cees Buisman, co-promotor(en): Jules van Lier; F.J. Cervantes. - [S.l.] : S.n. - ISBN 9085041341 - 176
ontkleuring - kleurstoffen (dyes) - azoverbindingen - textielindustrie - bioreactoren - afvalwaterbehandeling - anaërobe behandeling - decolorization - dyes - azo compounds - textile industry - bioreactors - waste water treatment - anaerobic treatment
The colour removal achieved under anaerobic conditions is also called reductive decolourisation, which is composed of a biological part, i.e. the reducing equivalents are biologically generated, and a chemical part, i.e. the formed electrons reduce chemically the dyes. The overall objective of this research was to explore different strategies to increase the reduction of dyes in bioreactors by using thermophilic anaerobic granular sludge and redox mediators
Effect of different redox mediators during thermophilic azo dye reduction by anaerobic granular sludge and comparative study between mesophilic (30C) and thermophilic (55C) treatments for decolourisation of textile wastewaters
Bezerra Dos Santos, A. ; Bisschops, I.A.E. ; Cervantes, F.J. ; Lier, J.B. van - \ 2004
Chemosphere 55 (2004)9. - ISSN 0045-6535 - p. 1149 - 1157.
afvalwater - degradatie - consortia - toxiciteit - waterverontreiniging - ontkleuring - anaërobe behandeling - afvalwaterbehandeling - redoxreacties - azoverbindingen - kleurstoffen (dyes) - slib - waste water - degradation - toxicity - water pollution - decolorization - anaerobic treatment - waste water treatment - redox reactions - azo compounds - dyes - sludges - waste-water - reactor - carbon - bn6
The impact of different redox mediators on colour removal of azo dye model compounds and textile wastewater by thermophilic anaerobic granular sludge (55 C) was investigated in batch assays. Additionally, a comparative study between mesophilic (30 C) and thermophilic (55 C) colour removal was performed with textile wastewater, either in the presence or absence of a redox mediator
The impact of different redox mediators on colour removal of azo dye model compounds and textile wastewater by thermophilic anaerobic granular sludge (55 degreesC was investigated in batch assays. Additionally, a comparative study between mesophilic (30 degreesC and thermophilic (55 degreesC colour removal was performed with textile wastewater, either in the presence or absence of a redox mediator. The present work clearly evidences the advantage of colour removal at 55 degreesC compared with 30 degreesC when dealing with azo coloured wastewaters. The impact of the redox mediators anthraquinone-2,6-disulfonate (AQDS), anthraquinone-2-sulfonate (AQS) and riboflavin was evident with all dyes, increasing decolourisation rates up to 8-fold compared with the mediator-free incubations. The generation of the hydroquinone form AH(2)QDS, i.e. the reduced form of AQDS, was extremely accelerated at 55 degreesC compared with 30 degreesC. Furthermore, no lag-phase was observed at 55 degreesC. Based on the present results we postulate that the production/transfer of reducing equivalents was the process rate-limiting step, which was accelerated by the temperature increase. It is conclusively stated that 55 degreesC is a more effective temperature for azo dye reduction than 30 degreesC which on the one hand can be attributed to the faster production/transfer of reducing equivalents, but also to the decrease in activation energy requirements. (C) 2004 Elsevier Ltd. All rights reserved.
The contribution of biotic and abiotic processes during azo dye reduction in anaerobic sludge
Zee, F.P. van der; Bisschops, I.A.E. ; Blanchard, V.G. ; Bouwman, R.H.M. ; Lettinga, G. ; Field, J.A. - \ 2003
Water Research 37 (2003)13. - ISSN 0043-1354 - p. 3098 - 3109.
rioolafvalwater - anaërobe behandeling - azoverbindingen - kleurstoffen (dyes) - redoxreacties - afvalwaterbehandeling - sewage effluent - anaerobic treatment - azo compounds - dyes - redox reactions - waste water treatment - redox mediators - decolorization - bacteria - system
Azo dye reduction results from a combination of biotic and abiotic processes during the anaerobic treatment of dye containing effluents. Biotic processes are due to enzymatic reactions whereas the chemical reaction is due to sulfide. In this research, the relative impact of the different azo dye reduction mechanisms was determined by investigating the reduction of Acid Orange 7 (AO7) and Reactive Red 2 (RR2) under different conditions. Reduction rates of two azo dyes were compared in batch assays over a range of sulphide concentrations in the presence of living or inactivated anaerobic granular sludge
Azo dye reduction results from a combination of biotic and abiotic processes during the anaerobic treatment of dye containing effluents. Biotic processes are due to enzymatic reactions whereas the chemical reaction is due to sulfide. In this research, the relative impact of the different azo dye reduction mechanisms was determined by investigating the reduction of Acid Orange 7 (AO7) and Reactive Red 2 (RR2) under different conditions. Reduction rates of two azo dyes were compared in batch assays over a range of sulphide concentrations in the presence of living or inactivated anaerobic granular sludge. Biological dye reduction followed zero order kinetics and chemical dye reduction followed second-order rate kinetics as a function of sulfide and dye concentration. Chemical reduction of the dyes was greatly stimulated in the presence of autoclaved sludge; whereas chemical dye reduction was not affected by living or gamma-irradiated-sludge. Presumably redox-mediating enzyme cofactors released by cell lysis contributed to the stimulatory effect. This hypothesis was confirmed in assays evaluating the chemical reduction of AO7 utilizing riboflavin, representative of the heat stable redox-mediating moieties of common occurring flavin enzyme cofactors. Sulfate influenced dye reduction in accordance to biogenic sulfide formation from sulfate reduction. In assays lacking sulfur compounds, dye reduction only readily occurred in the presence of living granular sludge, demonstrating the importance of enzymatic mechanisms. Both chemical and biological mechanisms of dye reduction were greatly stimulated by the addition of the redox-mediating compound, anthraquinone-disulfonate. Based on an analysis of the kinetics and demonstration in lab-scale upward-flow anaerobic sludge bed reactors, the relative importance of chemical dye reduction mechanisms in high rate anaerobic bioreactors was shown to be small due to the high biomass levels in the reactors. (C) 2003 Elsevier Science Ltd. All rights reserved.
Activated Carbon as an Electron Acceptor and Redox Mediator during the Anaerobic Biotransformation of Azo Dyes
Zee, F.P. van der; Bisschops, I.A.E. ; Lettinga, G. ; Field, J.A. - \ 2003
Environmental Science and Technology 37 (2003)2. - ISSN 0013-936X - p. 402 - 408.
slib - koolstof - redoxreacties - verontreinigende stoffen - azoverbindingen - kleurstoffen (dyes) - anaërobe behandeling - oxidatie - afvalwaterbehandeling - sludges - carbon - redox reactions - pollutants - azo compounds - dyes - anaerobic treatment - oxidation - waste water treatment - sp strain bn6 - oxidative dehydrogenation - catalytic-oxidation - hydrogen-sulfide - fluidized-bed - reduction - sludge - decolorization - degradation - quinones
The role of AC as redox mediator in accelerating the reductive transformation of pollutants as well as a terminal electron acceptor in the biological oxidation of an organic substrate is described. This study explores the use of AC as an immobilized redox mediator for the reduction of a recalcitrant azo dye in laboratory-scale anaerobic bioreactors, using volatile fatty acids as electron donor
Activated carbon (AC) has a long history of applications in environmental technology as an adsorbent of pollutants for the purification of drinking waters and wastewaters. Here we describe novel role of AC as redox mediator in accelerating the reductive transformation of pollutants as well as a terminal electron acceptor in the biological oxidation of an organic substrate. This study explores the use of AC as an immobilized redox mediator for the reduction of a recalcitrant azo dye (hydrolyzed Reactive Red 2) in laboratory-scale anaerobic bioreactors, using volatile fatty acids as electron donor. The incorporation of AC in the sludge bed greatly improved dye removal and formation of aniline, a dye reduction product. These results indicate that AC acts as a redox mediator. In supporting batch experiments, bacteria were shown to oxidize acetate at the expense of reducing AC. Furthermore, AC greatly accelerated the chemical reduction of an azo dye by sulfide. The results taken as a whole clearly suggest that AC accepts electrons from the microbial oxidation of organic acids and transfers the electrons to azo dyes, accelerating their reduction. A possible role of quinone surface groups in the catalysis is discussed.
Kick-off meeting EUROLIGNIN : September 19-20 2002, Evian-les-Bains, France
Gosselink, Richard - \ 2002
toepassingen - applications - research - kleurstoffen (dyes) - stralingsbeschermingsmiddelen - radiation protection agents - eigenschappen - lignine - properties - onderzoek - hechtmiddelen - Non-food Products (General) - coatings - adhesives - dyes - lignin - afdeklagen - biobased economy - Non-food producten (algemeen) - toepassingen - applications - research - kleurstoffen (dyes) - stralingsbeschermingsmiddelen - radiation protection agents - eigenschappen - lignine - properties - onderzoek - hechtmiddelen - Non-food Products (General) - coatings - adhesives - dyes - lignin - afdeklagen - biobased economy - Non-food producten (algemeen)
Presentatie aan het begin van het project EUROLIGNIN. Er wordt onderzoek gedaan naar verschillende toepassingen van lignine.
Anaerobic azo dye reduction
Zee, F.P. van der - \ 2002
Wageningen University. Promotor(en): G. Lettinga; J.A. Field. - S.l. : S.n. - ISBN 9789058086105 - 142
anaërobe behandeling - azoverbindingen - kleurstoffen (dyes) - redoxreacties - antrachinonen - anaerobic treatment - azo compounds - dyes - redox reactions - anthraquinones
<font size="3"><p>Azo dyes, aromatic moieties linked together by azo (-N=N-) chromophores, represent the largest class of dyes used in textile-processing and other industries. The release of these compounds into the environment is undesirable, not only because of their colour, but also because many azo dyes and their breakdown products are toxic and/or mutagenic to life. To remove azo dyes from wastewater, a biological treatment strategy based on anaerobic reduction of the azo dyes, followed by aerobic transformation of the formed aromatic amines, holds promise. However, the first stage of the process, anaerobic azo dye reduction, proceeds relatively slow. Therefore, this thesis research aimed at optimising anaerobic azo dye reduction, by studying the reaction mechanism and by consequently applying the obtained insights.</p><p>In this thesis it is shown that non-adapted anaerobic granular sludge has the capacity to non-specifically reduce azo dyes. As there was no correlation between a dye's reduction rate and its molecular characteristics (i.e. its size and its number of sulphonate groups and other polar substituents), it is unlikely that the mechanism of azo dye reduction involves cell wall penetration. Moreover, the presence of bacteria is not a prerequisite: azo dyes can also be reduced by sulphide in a purely chemical reaction. As dye containing wastewater usually contains sulphate and other sulphur species that will be biologically reduced to sulphide during treatment in anaerobic bioreactors, azo dye reduction will be a combination of biotic and abiotic processes. However, it was demonstrated that under normal conditions in high-rate anaerobic bioreactors (high sludge content, moderate sulphide levels), chemical azo dye reduction by sulphide hardly contributes to the overall reaction. Anaerobic azo dye reduction is therefore mainly a biological process, either a direct enzymatically catalysed reaction involving non-specific enzymes or a reaction with enzymatically reduced electron carriers. Azo dye reduction by sludge that had not earlier been exposed to dyes was found to relate to the oxidation of endogenous substrate and, especially, to the oxidation of hydrogen when present in bulk concentrations. Enrichment was required for the utilisation of electrons from volatile fatty acids for dye reduction.</p><p>Examination of the reduction of twenty chemically distinct azo dyes by anaerobic granular sludge revealed a large variation in the reaction rates. Especially reactive azo dyes with triazyl reactive groups were slowly reduced. For these common occurring reactive dyes, long contact times may be necessary to reach a satisfying extent of decolourisation. Consequently, they pose a serious problem for applying high-rate anaerobic treatment as the first stage in the biological degradation of azo dyes. However, this problem can be overcome by using redox mediators, compounds that speed up the reaction rate by shuttling electrons from the biological oxidation of primary electron donors or from bulk electron donors to the electron-accepting azo dyes.</p><p>It was observed that one of the constituent aromatic amines of the azo dye Acid Orange 7 had an autocatalytic effect on the dye's reduction, probably by acting as a redox mediator. Other compounds, e.g. the artificial redox mediator anthraquinone-2,6-disulphonate (AQDS), a compound that is known to catalyse the reductive transfer of several pollutants, and the commonly occurring flavin enzyme cofactor riboflavin, were found to be extremely powerful catalysts, capable of raising the pseudo first-order reaction rate constants by orders of magnitude. Moreover, a large stimulatory effect was found for autoclaved sludge, presumably due to the release of internal electron carriers, e.g. enzyme cofactors like riboflavin, during autoclaving.</p><p>AQDS was successfully applied to improve the continuous reduction of Reactive Red 2 (a reactive azo dye with a triazyl reactive group) in a lab-scale anaerobic bioreactor that was operated under moderate hydraulic loading conditions. Without AQDS, the reactor's dye removal efficiency was very low, which gave rise to severe dye toxicity towards the biological activity. Addition of catalytic concentrations of AQDS to the reactor influent caused an immediate increase of the dye removal efficiency and recovery of the methane production. Eventually, almost complete RR2 colour removal could be reached.</p><p>Though effective AQDS dosage levels are low, continuous dosing has disadvantages with respect to the costs and the discharge of this biologically recalcitrant compound. Therefore, the feasibility of activated carbon (AC), which is known to contain quinone groups at its surface, to act alternatively as an insoluble/immobilised redox mediator was explored. Incorporation of AC in the sludge of lab-scale anaerobic bioreactors that treated Reactive Red 2 in synthetic wastewater containing volatile fatty acid as primary electron donor resulted in enhanced continuous dye reduction as compared to the control reactors without AC. The effect of AC was in large excess of its dye adsorption capacity. In addition, it was shown that bacteria could utilise AC as terminal electron acceptor in the oxidation of acetate. Moreover, AC catalysis of chemical azo dye reduction by sulphide was demonstrated. These results clearly suggest that AC accepts electrons from the microbial oxidation of organic acids and transfers the electrons to azo dyes, thereby accelerating their biological reduction.</p><p>The research presented in this thesis makes clear that the reduction of azo dyes can be optimised by utilising redox mediators, i.e. either by continuous dosing of soluble quinones or by incorporation of AC in the sludge blanket. The potential of using redox mediators is probably not limited to enhancing azo dye reduction but may be extrapolated to other non-specific reductive (bio)transformations, e.g. reduction of halogenated or nitroaromatic compounds. The potential of using redox mediators is furthermore probably not limited to wastewater treatment but may also apply to bioremediation of soils polluted with e.g. polychlorinated solvents or nitroaromatic pesticides.
Cactus pear and cochineal in Cochabamba: the development of a cross-epistemological management toolkit for interactive design of farm innovation
Tekelenburg, A. - \ 2002
Wageningen University. Promotor(en): N.G. Röling; E.A. Goewie. - S.l. : S.n. - ISBN 9789058084798 - 191
bedrijfssystemen - innovaties - ontwerp - leren - interacties - cactaceae - opuntia ficus-indica - kleur - kleurstoffen (dyes) - verfsoorten - pigmenten - bolivia - coccidae - insecten - plantenplagen - voorlichting - participatie - boeren - integratie - plattelandsontwikkeling - bedrijfsvoering - landbouw - natuurlijke hulpbronnen - nuttig gebruik - bodemdegradatie - wetenschap - farming systems - innovations - design - learning - rural development - management - extension - participation - farmers - agriculture - natural resources - utilization - soil degradation - interactions - integration - insects - plant pests - colour - dyes - paints - pigments - science
<p>In this book, the local research and development process of the small-farmers (campesino) union of Huancarani (Cochabamba region in Bolivia) is discussed. Research activities were carried out by farmers themselves as well as by facilitators and scientists, but the farmers union kept control on planning, evaluation, decision-making and action. The book refers on the one hand to a technical issue; the development of cactus pear (Opuntia ficus-indica M.) and cochineal (Dactylopius coccus C.) production. The main question became why the experience was so successful. On the other hand it refers to a social issue (when the relation between farmers and scientists is addressed and applied methodology is analysed). The intellectual challenge for me was to show to a large and diversified public that, from a particular project, lessons can be drawn to improve interactive learning for farm innovation. This challenge has everything to do with the cooperation and communication issue between farmers and scientists. The exercise covers a reconstructed logic of applied research, design and development methodology and is therefore abstract. The final result of this exercise was the production of the management toolkit for the design of interactive learning processes. This toolkit became a practical instrument for managing and facilitating farm innovation processes in other contexts. It is the <em>development</em> of this toolkit, the learning process, based on the mantra learning in practice - learning from practice - learning for practice, that I want to share with other scientists and development workers.</p>
Integrated and sequential anaerobic/aerobic biodegradation of azo dyes
Tan, N.G.C. - \ 2001
Wageningen University. Promotor(en): G. Lettinga; J.A. Field. - S.l. : S.n. - ISBN 9789058083746 - 104
biodegradatie - bioremediëring - kleurstoffen (dyes) - azoverbindingen - biodegradation - bioremediation - dyes - azo compounds
<p>Azo dyes constitute a major class of environmental pollutants accounting for 60 to 70% of all dyes and pigments used. These compounds are characterized by aromatic moieties linked together with azo groups (-N=N-). The release of azo dyes into the environment is a concern due to coloration of natural waters and due to the toxicity, mutagenicity and carcinogenicity of the dyes and their biotransformation products. Therefore, considerable attention has been given to evaluating the fate of azo dyes during wastewater treatment and in the natural environment. Azo dyes require an anaerobic and an aerobic phase for their complete biodegradation. Therefore, the aim of this thesis was to evaluate the mineralization of azo dyes under integrated and sequential anaerobic/aerobic conditions. These conditions were applied on three azo dyes, Mordant Orange 1 (MO1), 4-phenylazophenol (4-PAP) and Mordant Yellow 10 (MY10). Since many azo dyes are substituted with a sulfonic acid group, special attention was paid to the sulfonated azo dyes and their biodegradation products, the sulfonated aromatic amines.</p><p>The first step in the biodegradation of azo dyes is the azo dye reduction resulting in the formation of the aromatic amines. The influence of oxygen on the azo dye reduction of MO1 was tested in order to evaluate the integrated anaerobic/aerobic conditions. The co-substrate ethanol was successfully applied as electron donor for azo dye reduction and also created anaerobic microniches to facilitate anaerobic azo dye reduction in the presence of oxygen. Increasing oxygen concentrations showed decreasing azo dye-reduction rates with ethanol as co-substrate. These rates were higher when applying acetate as co-substrate. Moreover, Nedalco granular sludge could withstand better with the applied integrated anaerobic/aerobic conditions than Shell granular sludge.</p><p>Since none of the expected aromatic amines from MO1 was degraded, further research was conducted to evaluate the aerobic biodegradation of aromatic amines. MY10 and 4-PAP were tested under integrated anaerobic/aerobic conditions. All aromatic amines were removed if sufficient oxygen was present. Oxygen was primarily used to oxidize co-substrate and if sufficient oxygen was available the formed aromatic amines were further degraded. The removal of 4-aminobenzenesulfonic acid (4-ABS) was only possible after bioaugmentation of a 4-ABS-degrading enrichment culture. The results from the biodegradation study of 4-AP indicated that 4-aminophenol was removed due to autoxidation. Degradation of azo dyes is possible under integrated anaerobic/aerobic conditions if co-substrate and oxygen are in balance.</p><p>In the sequential anaerobic/aerobic bioreactor, the azo dye MY10 was successfully mineralized. Its constituent aromatic amines, 5-aminosalicylic acid (5-ASA) and 4-ABS, were both recovered in the anaerobic stage and degraded in the aerobic stage. Biodegradation of the 4-ABS was only possible after bioaugmentation with a 4-ABS-degrading enrichment culture. High recovery of sulfate indicated mineralization of 4-ABS. After long-term exposure to 5-ASA, the anaerobic granular sludge showed the ability to degrade this compound.</p><p>It was observed that the degradation of the sulfonated aromatic amine 4-ABS only proceeded after bioaugmentation of a specialized enrichment culture. Therefore, the ultimate biodegradability of the sulfonated aromatic amines is questionable. To investigate this matter, the fate of sulfonated aromatic amines with natural mixed cultures was evaluated in aerobic and anaerobic batch assays and bioreactor experiments. None of the ten tested compounds was degraded under anaerobic conditions and only 2-ABS and 4-ABS were aerobically mineralized. This was observed in batch as well as in bioreactor experiments. Degradation of the 2-ABS and 4-ABS was found with inoculum sources that were historically polluted with sulfonated aromatic compounds. At concentrations up to 1.0 g l <sup>-1</sup> , none of the tested sulfonated aromatic amines showed any toxicity towards anaerobic and aerobic biomass.</p><p>The results of this research demonstrated that azo dyes are mineralized under integrated and sequential anaerobic/aerobic conditions. Due the difficulties with balancing the supply of co-substrate and oxygen in integrated anaerobic/aerobic systems, the sequential anaerobic/aerobic conditions are recommended for the mineralization of azo dyes. However, during the degradation of sulfonated azo dyes, many different sulfonated aromatic amines will be formed and these compounds are not likely to be degraded aerobically. Therefore, special attention should be paid on the removal of these compounds</p>
Plant resources of South-East Asia. No. 3: Dye and tannin-producing plants
Wulijarni-Soetjipto, N. ; Siemonsma, J.S. - \ 1991
Bogor : PROSEA Foundation - ISBN 9789022009871 - 195
verfplanten - kleurstoffen (dyes) - genenbanken - genetische bronnen - germplasm - oorsprong - genetische bronnen van plantensoorten - hulpbronnenbehoud - looizuurleverende planten - tanninen - bomen - schors, bomen - zuidoost-azië - bosproducten anders dan hout - nieuwe cultuurgewassen - dye plants - dyes - gene banks - genetic resources - origin - plant genetic resources - resource conservation - tan plants - tannins - trees - bark - south east asia - non-wood forest products - new crops
Traceren van boter d.m.v. het toevoegen van kleur- en/of smaakstoffen
Labrijn, J.F. ; Schouten, J.C. ; Veen, N.G. van der; Sledsens, A.M.J. - \ 1985
Wageningen : RIKILT (Rapport / RIKILT 85.109) - 3
boter - toevoegingen - pigmenten - kleurstoffen (dyes) - butter - additives - pigments - dyes
Verschillende kleur- en aromastoffen zoals indigotine, chlorofyl , enocyanine, bietenrood, vanille en een lakton zijn in verschillende hoeveelheden aan boter toegevoegd. De verdeling van de kleur- en aromastoffen was in de meeste gevallen homogeen. De kleuring was bij verschillende concentraties voldoende om als tracer te gebruiken. Een vereiste was echter dat de kleur grotendeels afgebroken werd bij verhitten. Dit was bij een aantal kleurstoffen het geval.
Cochenille (Cochenial)
Anonymous, - \ 1976
Wageningen : [s.n.] (Literatuurlijst / Centrum voor landbouwpublikaties en landbouwdocumentatie no. 3897)
dierlijke producten - bibliografieën - coccoidea - coccus - kleurstoffen (dyes) - kweken - animal products - bibliographies - dyes - rearing
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