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 - 12 / 12

    • help
    • print

      Print search results

    • export

      Export search results

    Check title to add to marked list
    Role of protein-protein interactions on protein aggregation and emulsion flocculation
    Delahaije, R.J.B.M. - \ 2014
    Wageningen University. Promotor(en): Harry Gruppen, co-promotor(en): Peter Wierenga. - Wageningen : Wageningen University - ISBN 9789462570054 - 158
    methaanproductie - elektrochemie - kooldioxide - elektrolyse - microbiële brandstofcellen - duurzame energie - methane production - electrochemistry - carbon dioxide - electrolysis - microbial fuel cells - sustainable energy

    In this thesis, the effect of molecular properties on the aggregation and flocculation behaviour is studied. The aggregation behaviour was thought to be mainly affected by the structural stability of the protein. A decreased structural stability results in unfolded proteins which are more prone to aggregation. The flocculation behaviour was shown to be affected by the adsorbed amount at saturation and the adsorption rate. These parameters have been combined in a surface coverage model, which describes the stabilization of emulsions away from the iso‑electric point (pI) to be affected by excess protein in the continuous phase. In addition, a model was proposed for the prediction of the adsorbed amount at saturation. This is influenced by the protein charge and radius and system conditions (i.e. pH and ionic strength). The adsorption rate, which is a measure for the affinity of the protein towards the adsorption to the interface, was shown to increase with increasing relative exposed hydrophobicity and a decrease of the electrostatic repulsion (i.e. decrease of ionic strength or the protein charge). Close to the pI, the applicability of protein-stabilized emulsions is limited. Hence, a steric interaction was introduced to stabilize the emulsion. It was shown that glycation of the protein with a trisaccharide was sufficient to sterically stabilize the emulsions against pH-induced flocculation.

    Ontwikkeling van veilige toepassingen voor gewasbehandelingen met electrolysewater in de glastuinbouw
    Hofland-Zijlstra, J.D. ; Vries, R.S.M. de; Blok, C. ; Boer-Tersteeg, P.M. de; IJdo, M.L. ; Bosch, C. ; Ayik, A. ; Bruning, H. - \ 2013
    Bleiswijk : Wageningen UR Glastuinbouw (Rapporten WUR GTB 1240) - 50
    water - elektrolyse - glastuinbouw - gewasbescherming - milieubescherming - arbeidsomstandigheden - plantenvoeding - biociden - ultrasone behandeling - verneveling - druppelbevloeiing - nederland - water - electrolysis - greenhouse horticulture - plant protection - environmental protection - working conditions - plant nutrition - biocides - ultrasonic treatment - nebulization - trickle irrigation - netherlands
    Dit onderzoek had als doel om de werking van electrolysewater te verbinden met de chemische eigenschappen en op zoek te gaan naar veilige toepassingen als gewasbehandeling voor de glastuinbouwsector. Vijf producenten hebben voor dit onderzoek de gewenste samenstelling van electrolysewater aangeleverd. Alle producten met daarin 36-65 ppm vrij chloor waren binnen vijf minuten 100% effectief tegen de bacterie, Erwinia chrysanthemi en de schimmel, Botrytis cinerea. De grenzen van gewasschade in de kiemplantentest werden sterker bepaald door de hoeveelheid natriumzout en EC gehalte van de electrolysevloeistof dan de hoeveelheid vrij chloor. In een korte meedruppelproef met tomaat zijn verschillende concentraties vrij chloor (0, 4, 8, 20 ppm) gedoseerd aan het voedingswater. Er werd geen gewasschade gevonden of negatief effect op de wortelkolonisatie van Trianum door de geringe chloorwaardes (vrij en totaal) die na vier weken bij de druppelaar werden teruggemeten. Testen met gewasbehandelingen laten zien dat éénmalige behandelingen tot 300 ppm geen gewasschade geven. Bij meerdere toepassingen is groeiremming te voorkomen door lagere concentraties te gebruiken of blootstellingstijd te beperken. Electrolysewater kan een veilig en bruikbaar alternatief bij het terugdringen van het fungicidegebruik.
    Electrolysed water is 'The New Bleach' (interview with Jantineke Hofland-Zijlstra)
    Bouwman-van Velden, P. ; Hofland-Zijlstra, J.D. - \ 2013
    In Greenhouses : the international magazine for greenhouse growers 2013 (2013)April. - ISSN 2215-0633 - p. 44 - 45.
    glastuinbouw - gewasbescherming - elektrolyse - elektrische stroom - desinfecteren - plagenbestrijding - zout water - landbouwkundig onderzoek - greenhouse horticulture - plant protection - electrolysis - electric current - disinfestation - pest control - saline water - agricultural research
    Jantineke Hofland-Zijlstra boekt resultaat: electrolysewater is eigenlijk 'Het Nieuwe Chloor' (interview met Jantineke Hofland-Zijlstra)
    Bouwman-van Velden, P. ; Hofland-Zijlstra, J.D. ; Vries, R.S.M. de - \ 2013
    Onder Glas 10 (2013)2. - p. 24 - 25.
    glastuinbouw - gewasbescherming - elektrolyse - elektrische stroom - desinfecteren - plagenbestrijding - zout water - landbouwkundig onderzoek - snijbloemen - greenhouse horticulture - plant protection - electrolysis - electric current - disinfestation - pest control - saline water - agricultural research - cut flowers
    Aan het woord is Jantineke Hofland-Zijlstra, die bij Wageningen UR Glastuinbouw samen met Rozemarijn de Vries een door het Productschap Tuinbouw gefinancierd onderzoek doet naar veilige toepassingen voor gewasbehandelingen met electrolysewater.
    Effectiviteit van electrolysewater tegen Venturia inaequalis (schurft)
    Schoorl, F.W. ; Jong, P.F. de - \ 2012
    Wageningen : Wageningen UR - 3
    malus - appels - venturia inaequalis - gewasbescherming - elektrolyse - elektrische stroom - desinfecteren - plagenbestrijding - proefopzet - malus - apples - venturia inaequalis - plant protection - electrolysis - electric current - disinfestation - pest control - experimental design
    Effectiviteit bepalen van electrolysewater ter bestrijding van schurft, Venturia inaequalis op appelbladeren.
    Ecophysiology of microorganisms in microbial elctrolysis cells
    Croese, E. - \ 2012
    Wageningen University. Promotor(en): Fons Stams; G.J.W. Euverink, co-promotor(en): J.S. Geelhoed. - S.l. : s.n. - ISBN 9789461733047 - 149
    microbiële fysiologie - ecofysiologie - elektrolyse - microbiële brandstofcellen - microbial physiology - ecophysiology - electrolysis - microbial fuel cells

    One of the main challenges for improvement of the microbial electrolysis cell (MEC) has been the reduction of the cost of the cathode catalyst. As catalyst at the cathode, microorganisms offer great possibilities. Previous research has shown the principle possibilities for the biocathode for H2 production with mixed microbial communities. In this thesis we analyzed the microbial communities from several biocathodes for H2 production. The microbial population of the very first MEC biocathode for H2 production (Chapter 2) showed a dominant population of Desulfovibrio spp.. A member of those dominant species, Desulfovibrio strain G11 was reinoculated in a biocathode and produced current and H2. On basis of previous knowledge of known Desulfovibrio spp., the molecular mechanism of electron uptake from a cathode with H2 production was proposed to have similarities to mechanisms that have been proposed for syntrophic growth.
    In Chapter 3 the microbial population of 5 more MEC biocathodes was analyzed. Those MECs were fed with either acetate or bicarbonate and consisted of two different designs. The results showed that the microbial communities from the same setup design are more similar than fed with the same carbon source. Furthermore, ribotypes from the phyla, Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria were found to be dominant. To understand more on the mechanisms of H2 production in the MEC, a hydrogenase gene microarray was used to analyze the hydrogenase genes present in 3 of the cathode samples. Those results showed that genes coding for bidirection NAD(P) dependent hydrogenases were mostly present in the MEC biocathode. Those results suggest a mechanisms involving cytoplasmatic NAD(P) dependent hydrogenases rather than energy converting hydrogenases as proposed before.
    To understand the molecular mechanisms it is important to obtain pure cultures from the MEC biocathode and test them for biocathode activity. In chapter 4 we describe a Citrobacter species strain PS2 which was isolated from the MEC biocathode. PS2 was very similar to other Citrobacter spp. able to produce fermentative H2 from a diversity of carbon sources. When inoculated in the MEC biocathode fed with pyruvate, current increased and H2 was produced with comparable efficiencies and production rates as mixed cultures biocathodes. Addition of membrane potential uncouplers nigericin and monensin showed no change in current and H2 production rates, suggesting that the molecular mechanism does not involve membrane potential driven processes.
    Finally, in chapter 5, we explored the usefulness of statistical methods to pinpoint which species are most important for MEC performance. We analyzed DGGE profiles from 5 different MEC anodes using two distinct statistical techniques, Radundacy analysis (RDA) and QR factorization (QRE), and tried to link those profiles to experimental data current, resistance, potential and overpotential. The results showed that current was mostly related to species composition and we were able to pinpoint a few band from DGGE that were influencing changes in experimental parameters most. The results showed that both RDA and QRE are useful methods, of which RDA takes all bands into account, but is therefore less precise; QRE is numerical precise but by eliminating bands that explain least of the variation and therefore using QRE might neglect effect of those bands. Altogether, RDA with additional QRE is useful to give an indication of which species from a mixed community are most likely important for MEC performance and can be used to find a focus in mixed community analysis.
    From our results we conclude that a large diversity of bacteria is able to catalyze the biocathodes reaction for H2 production. The species that develop at a cathode might be largely influenced by the design of the used setup, which has to be considered when comparing different experiments. In addition, our results suggest that a general mechanism, present in many different bacterial species, is involved in MEC H2 production. We propose a molecular mechanism involving a series of cytochromes and cytoplasmatic H2 production by NAD(P)+ dependent bidirectional hydrogenases that use energy from electrons derived from the cathode. The biocathode is a promising technology for application in the MEC, although to date the chemical cathodes still outcompete the biocathode, the biocathode offers great possibilities for future applications including production of other products such as ethanol, methane, succinate or acetate.

    Voortgang project Toepassing van electrolysewater in de glastuinbouw
    Hofland-Zijlstra, J.D. ; Vries, R.S.M. de; Bruning, H. - \ 2012
    elektrolyse - gewasbescherming - glastuinbouw - erwinia - botrytis - electrolysis - plant protection - greenhouse horticulture - erwinia - botrytis
    Poster met onderzoeksinformatie.
    Cathode innovations for enhanced H2 production through microbial electrolysis
    Jeremiasse, A.W. - \ 2011
    Wageningen University. Promotor(en): Cees Buisman, co-promotor(en): Bert Hamelers; Mieke Kleijn. - [S.l.] : S.n. - ISBN 9789085859895 - 168
    elektrolyse - microbiële activiteiten - bio-energie - biomassa - waterstof - biobased economy - electrolysis - microbial activities - bioenergy - biomass - hydrogen - biobased economy
    Met een microbiële elektrolysecel (MEC) kan waterstof worden gewonnen uit organische reststromen. Aan de bioanode van een MEC zetten elektrochemisch actieve bacteriën organisch materiaal om in stroom, welke vervolgens aan de kathode wordt omgezet in waterstof. Dit proces behoeft een aangelegd voltage van zo’n 0.4 tot 1.0 V. Dit proces combineert dus de omzetting van reststromen met de productie van een waardevol product; waterstof. Binnen dit onderzoek is gekeken naar goedkope alternatieven voor de platinakathode. Door gebruik te maken van, voor dit proces, innovatieve kathoden zoals kathoden gebaseerd op niet-edele metalen blijkt het mogelijk om de waterstofproductie aanmerkelijk te verhogen en tegelijkertijd de MEC kosten te verlagen. Daarmee is een grote stap gezet richting de ontwikkeling van een rendabele MEC.
    Kennisinventarisatie naar de achtergronden en toepassingen van electrochemisch geactiveerd water in de agrarische sector
    Hofland-Zijlstra, J.D. ; Vries, R.S.M. de; Bruning, H. - \ 2011
    Bleiswijk : Wageningen UR Glastuinbouw (Rapporten GTB 1087) - 38
    elektrochemie - water - toepassingen - landbouw - tuinbouw - ultrasone behandeling - verneveling - teelt onder bescherming - ziektebestrijdende teeltmaatregelen - elektrolyse - electrochemistry - water - applications - agriculture - horticulture - ultrasonic treatment - nebulization - protected cultivation - cultural control - electrolysis
    Wageningen UR Greenhouse Horticulture, with funding of Dutch Horticultural Board, has described the history and background of electrochemically activated water and explored possibilities for applications within the agricultural sector. In the Netherlands, the use of activated water as a biocide is allowed since 2009. Active ingredients of activated water are chlorine gas, hypochlorous acid and hypochlorite. Together with a high oxidation-reduction potential (ORP 750-1100 mV) there is a broad activity against bacteria, fungi, viruses, algae, protozoa and nematodes. Agricultural applications of activated water are described for seed disinfection, cleaning equipment and packing materials, removal of biofilms from pipes, disinfection of flowers, fruits and vegetables. The recent development of ultrasonic atomization of activated water created new possibilities to treat crops and harvested products against pathogens without excessive volumes of water and disinfect air from pathogens. For applications in protected crops it is desirable that the corrosive properties of the activated water should be minimized and capacities of dispensing equipment must be enlarged.
    Microbial electrolysis kinetics and cell design
    Sleutels, T.H.J.A. - \ 2010
    Wageningen University. Promotor(en): Cees Buisman, co-promotor(en): Bert Hamelers. - S.l. : s.n. - ISBN 9789085858201 - 127
    elektrolyse - industriële microbiologie - waterstof - biomassa - biomassaconversie - electrolysis - industrial microbiology - hydrogen - biomass - biomass conversion
    Large amounts of hydrogen are produced worldwide, which are nearly all from fossil origin. Use of biomass instead of fossil fuels to produce hydrogen can contribute to a reduction of greenhouse gas emissions. Therefore, the hydrogen has to be produced at high yield and efficiency. A Microbial Electrolysis Cell is a new technology that is able to produce hydrogen at high yield and efficiency in one step from biomass by addition of only a small amount of energy.
    The energy that needs to be added to produce hydrogen is determined by the internal resistance of the system, which can be divided into the different components of the system and presented as an equivalent circuit. These partial internal resistances were used to explain the difference in performance of Microbial Electrolysis Cells equipped with cation and anion exchange membranes. The better performance of the anion exchange membrane configuration was caused mainly by the much lower internal resistance due to the transport resistance of ions.
    The hydrogen production rate is determined by conversion rate of substrate and the coulombic efficiency of this conversion. The current density and coulombic efficiency was influenced by chancing the mass and charge transport in porous electrodes. Increase of a forced flow speed through the porous electrodes led to an increase in current density when the flow was directed away from the membrane caused by a decrease in anode resistance. Furthermore, the increase in flow speed led to an increase of the coulombic efficiency.
    The coulombic efficiency can also be influenced by changing the substrate concentration and the anode potential. It was shown that a higher anode potential increased the energy available for these electrogens and in that way they could outcompete the methanogens. Furthermore, also a lower substrate concentration made it possible for the electrogens to outcompete the methanogens.
    Finally, a system was developed that makes it possible to recycle alkalinity from waste streams in an extra recovery compartment and to produce the same current without addition of expensive buffer.
    In the future, improvement of the following three key characteristics can make Microbial Electrolysis Cells a competing technology for the production of hydrogen gas from biomass. Firstly, the coulombic efficiency needs to be controlled and improved to reach values close to 100% for all possible organic substrates. Secondly, the use of materials and the design should be such that the total internal resistance does not exceed values of 30 mΩ m2. Thirdly, the use of added chemicals like buffers should be limited, as the relative productivity does not increase with increasing use of chemicals.
    Effect of the type of ion exchange membrane on performance, ion transport, and pH in biocatalyzed electrolysis of wastewater
    Rozendal, R.A. ; Sleutels, T.H.J.A. ; Hamelers, H.V.M. ; Buisman, C.J.N. - \ 2008
    Water Science and Technology 57 (2008)11. - ISSN 0273-1223 - p. 1757 - 1762.
    afvalwaterbehandeling - waterzuivering - membranen - filtratie - elektrolyse - waterstof - ionenuitwisselingsbehandeling - ionentransport - anionenwisseling - waste water treatment - water treatment - membranes - filtration - electrolysis - hydrogen - ion exchange treatment - ion transport - anion exchange - microbial fuel-cells - bacterium - acetate - cation
    Previous studies have shown that the application of cation exchange membranes (CEMs) in bioelectrochemical systems running on wastewater can cause operational problems. In this paper the effect of alternative types of ion exchange membrane is studied in biocatalyzed electrolysis cells. Four types of ion exchange membranes are used: (i) a CEM, (ii) an anion exchange membrane (AEM), (iii) a bipolar membrane (BPM), and (iv) a charge mosaic membrane (CMM). With respect to the electrochemical performance of the four biocatalyzed electrolysis configurations, the ion exchange membranes are rated in the order AEM > CEM > CMM > BPM. However, with respect to the transport numbers for protons and/or hydroxyl ions (t(H/OH)) and the ability to prevent pH increase in the cathode chamber, the ion exchange membranes are rated in the order BPM > AEM > CMM > CEM.
    Hydrogen production through biocatalyzed electrolysis
    Rozendal, R.A. - \ 2007
    Wageningen University. Promotor(en): Cees Buisman, co-promotor(en): Bert Hamelers. - [S.l.] : s.n. - ISBN 9789085047315 - 207
    waterstof - afvalwaterbehandeling - elektrolyse - biologische productie - brandstoffen - innovaties - technologie - energiebronnen - energie - biokatalyse - hydrogen - waste water treatment - electrolysis - biological production - fuels - innovations - technology - energy sources - energy - biocatalysis - cum laude
    cum laude graduation (with distinction) To replace fossil fuels, society is currently considering alternative clean fuels for transportation. Hydrogen could be such a fuel. In theory, large amounts of renewable hydrogen can be produced from organic contaminants in wastewater. During his PhD research René Rozendal has developed a new technology for this purpose: biocatalyzed electrolysis. The innovative step of biocatalyzed electrolysis is the application of electrochemically active microorganisms in combination with small input of electrical energy. Electrochemically active microorganisms are a special group of microorganisms that are able to use an electrode as electron acceptor for the oxidation of organic material. Biocatalyzed electrolysis couples this “bio-electrode” to a hydrogen generating electrode by means of a power supply. Consequently, organic contaminants in wastewater can be oxidized (i.e. the wastewater is treated), while at the same time hydrogen is generated as a valuable product. In this way biocatalyzed electrolysis can significantly increase the hydrogen yield from wastewaters compared to other technologies. Furthermore, the innovative design makes a much wider variety of wastewaters than before suitable for hydrogen production. This makes biocatalyzed electrolysis a breakthrough technology for hydrogen production from wastewaters
    Check title to add to marked list

    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.