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

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Anaerobic manganese- or iron-mediated pharmaceutical degradation in water
Liu, Wenbo - \ 2018
Wageningen University. Promotor(en): Huub Rijnaarts, co-promotor(en): Alette Langenhoff; Nora Sutton. - Wageningen : Wageningen University - ISBN 9789463432214 - 235
drugs - biodegradation - anaerobic conditions - manganese oxides - iron oxides - removal - water pollution - geneesmiddelen - biodegradatie - anaërobe omstandigheden - mangaanoxiden - ijzeroxiden - verwijdering - waterverontreiniging

Pharmaceutical compounds, originating mainly from industrial production and public consumption, are detected at extremely low levels (ng·L-1 –µg·L-1) in groundwater, surface water, and wastewater. So far, the adverse effects of pharmaceuticals and their intermediates have been widely reported, and include toxicity to humans and ecosystem, and enhancement of antimicrobial resistance. These effects call for the elimination of pharmaceuticals from water. This can be done by both abiotic and biotic degradation in the presence of oxygen (aerobic conditions) or in the absence of oxygen (anaerobic conditions). The technologies under anaerobic conditions are generally more sustainable and attractive because they require less energy and produce less pollutants, such as greenhouse gas, compared to technologies under aerobic conditions. Anaerobic degradation with metal oxides such as manganese (Mn) or iron (Fe) oxides has clear advantages in both drinking water treatment and wastewater treatment. Therefore, anaerobic degradation of pharmaceuticals in water with Mn or Fe is promising to study and develop into applicable techniques. This thesis investigates the feasibility of anaerobic degradation of pharmaceuticals in Mn- and Fe-mediated systems via both abiotic removal processes and by biodegradation. In Chapter 1, the scientific and technological motivation of the thesis is proposed.

Applications and scientific developments of Mn- or Fe-based technologies to remove pharmaceuticals from water are reviewed and discussed in Chapter 2. Based on the removal mechanisms found in nature and technical systems, these Mn- or Fe-based technologies can be classified into 3 groups – physico-chemical removal, chemical removal, and biologically-related removal. A review of previous research indicates that pharmaceutical removal with Mn- or Fe-based technologies from water is efficient, and the removal efficiency varies whit the different technologies applied. Positive and negative aspects of these processes, such as (non-)specificity, treatment conditions, formation of and effects of intermediates and by-products, and effects of Mn or Fe compounds were evaluated. Based on that, new and promising Mn- or Fe-based technologies are proposed as future potential effective and sustainable pharmaceutical removal technologies. Among these proposed technologies, the dissimilatory Mn or Fe reduction is identified as a most attractive, sustainable, and low-cost technology because this novel technology requires neutral conditions and the bacteria involved are able to completely mineralize the pharmaceuticals.

The anaerobic biodegradation of pharmaceuticals coupled to dissimilatory Mn(IV) or Fe(III) reduction is tested with different types of Mn(IV) and Fe(III) (Chapter 3). With a mixture of adapted sediment to metoprolol and chemically synthesized Mn(IV), anaerobic biodegradation with amorphous, chemically synthesized Mn(IV) can effectively remove caffeine (26%) and naproxen (52%) after 42 days of incubation. Further experiments with Mn(IV) obtained from drinking water treatment plants show that this type of Mn(IV) can be used to remove metoprolol and propranolol, with respectively 96% and 31% after 72 days of incubation. The inoculum can also use Fe(III) as alternative electron acceptor to degrade metoprolol. Results show that metoprolol degradation with insoluble chemically synthesized Fe(III) and soluble Fe(III)-citrate reaches 57% and 52%, respectively. No significant removal is observed in all the abiotic controls, showing that the biodegradation is the main removal mechanism in pharmaceutical removal with Mn(IV) or Fe(III).

Abiotic removal of selected pharmaceuticals with MnO2 is compared under aerobic conditions and anaerobic conditions (Chapter 4). Results show that anaerobic conditions promote diclofenac removal, while it inhibits removal of metoprolol and propranolol. In demineralized water (demiwater), diclofenac removal under anaerobic conditions is 78%, and higher than the 59% found under aerobic conditions. In 50 mM phosphate buffer, and under aerobic conditions, the diclofenac removal achieves complete removal. Under anaerobic conditions the observed removal is similar as in demiwater. Preliminary investigation shows that diclofenac removal with MnO2 under anaerobic condition is better at acidic pH (pH 4 – 5) and the removal is higher when applying amorphous MnO2 compared to applying crystalline MnO2. The key factors determining the extent of pharmaceutical removal with MnO2 under anaerobic conditions are the following: the chemical structure and molecular properties of the pharmaceuticals, and the properties and activity of reactive sites on the MnO2 surface.

Applying MnO2 under anaerobic conditions to remove diclofenac from water is further investigated (Chapter 5). Results show that increasing the temperature from 10 to 30°C leads to an increase in the diclofenac removal, whereas further increase of temperature to 40°C results in a decrease in the removal. The latter effect is possibly due to Ostwald ripening and/or aging processes. Increasing the amount of MnO2 increases the diclofenac degradation, as this provides more reactive sites for diclofenac conversions. Further shifting the molar ratio of MnO2 and diclofenac from 2200:1 to 8900:1, however, does not further increase diclofenac removal, probably due to limited oxidation capacity of MnO2. The presence of metal ions strongly inhibits the diclofenac removal following the order of Mn2+> Ca2+ ≈ Mg2+ >Fe3+. The metal ions appear to adsorb onto the MnO2 surface and compete with diclofenac for reactive sites. Phosphate has a diverse effect on diclofenac degradation: low concentrations inhibit and high concentrations promote the removal. The humic acids significantly promotes diclofenac removal, probably caused by affecting MnO2 reactive surface sites.

To reuse the Mn or Fe during pharmaceutical removal under anaerobic conditions, biological production of Mn(IV) or Fe(III) is investigated under oxygen-limiting conditions, or with nitrate as electron acceptor (Chapter 6). Mn(IV) is successfully produced with Mn(II)-oxidizing bacteria under O2-limiting conditions, and the produced Mn(IV) is amorphous. Pharmaceutical removal with the Mn(II)-oxidizing bacteria is not observed. In abiotic pharmaceutical removal, using Mn(IV) from a drinking water production plant, is effective to remove metoprolol and propranolol. The successful production of Fe(III) is also observed under NO3--reducing conditions via biological processes. The biologically produced Fe(III) is also amorphous. There is no significant removal of pharmaceuticals coupled to the biological Fe(III) production. When comparing the biologically produced Fe(III) and other types of Fe(III), only Fe(III) from a drinking water production plant and one Fe(III)-based sorbent can remove propranolol.

Finally, the outcomes of this thesis are discussed and provide insights into the application of anaerobic degradation of pharmaceuticals with mediation of Mn and Fe oxides (Chapter 7). The removal mechanisms include adsorption, chemical oxidation, and biodegradation and are identified to contribute to the different removal processes. The anaerobic Mn(IV)- and Fe(III)-mediated pharmaceutical degradation processes are evaluated on the basis of removal performance, environmental and operational conditions, sustainability of the processes, as well as the Mn and Fe types involved. Results described in this thesis provide a proof of principal for anaerobic Mn(IV)- or Fe(III)-mediated degradation in removing pharmaceuticals from water. To translate the process into a pharmaceutical removal technology for water treatment, three steps are proposed including (1) exploring the limits of anaerobic Mn- or Fe-mediated pharmaceutical degradation processes; (2) simulating the process in practice with a controlled systems, and (3) translating the processes to a pilot-scale system before a full-scale application. In addition, research topics are identified that can help to meet these challenges in the future. In summary, anaerobic Mn(IV)- or Fe(III)-mediated systems can remove pharmaceuticals from water through both abiotic removal and biotic degradation. These are promising processes which can be developed into a robust, sustainable, affordable, and environmentally friendly technology to remove pharmaceuticals from water.

Evaluatie zuiveringstechniek voor verwijdering gewasbeschermingsmiddelen III
Ruijven, J.P.M. van; Beerling, E.A.M. ; Staaij, M. van der; Os, E.A. van - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1414) - 30
afvalwaterbehandeling - waterzuivering - afvalwater - waterverontreiniging - glastuinbouw - kassen - cultuur zonder grond - gewasbescherming - pesticiden - ozon - verwijdering - filtratie - technieken - waste water treatment - water treatment - waste water - water pollution - greenhouse horticulture - greenhouses - soilless culture - plant protection - pesticides - ozone - removal - filtration - techniques
Dutch greenhouse horticulture has to treat all discharged water from soilless cultivations for the removal of plant protection products, to meet the new Dutch Directive Hoofdlijnenakkoord (2015). Building on previous research, (1) the life span of activated carbon filters, (2) the effect of increasing concentrations of plant protection products on the removal efficacy of ozone and the removal efficacy of (3) multimedia filtration and (4) ultrasonic water treatment have been investigated. It turned out to be difficult to design an active carbon based water treatment system capable of durable treatment of greenhouse discharge water: organic and mineral material in the water blocked the pores, thereby clogging the filter system and causing leakage by pressure build-up. Activated carbon filtration (granular activated carbon, 48 min contact time, 50 μm prefiltration with sand filter) achieved a removal efficacy of >95% for up to 430 bed volumes treated. Combination with advanced oxidation improved the removal efficacy, but the removal time of the filter could not be determined due to leakage. The removal efficacy of ozone oxidation remained >98%, even at increased concentrations (factor 10 and 100) of plant protection products in the untreated water. The multimedia filter removed 75% of the plant protection products by adsorption, biological breakdown within the filter was not determined. Treatment of the water with ultrasonic waves hardly had any effect (maximum 30% efficacy) on the breakdown.
Removal of micropollutants in source separated sanitation
Butkovskyi, A. - \ 2015
Wageningen University. Promotor(en): Huub Rijnaarts; Grietje Zeeman, co-promotor(en): L. Hernández Leal. - Wageningen : Wageningen University - ISBN 9789462574168 - 189
verontreinigende stoffen - verontreiniging - waterverontreiniging - afvalwater - stedelijk afvalwater - volksgezondheidsbevordering - waterzuivering - verwijdering - geneesmiddelen - farmaceutische producten - antibioticumresiduen - residuen - pollutants - pollution - water pollution - waste water - municipal wastewater - sanitation - water treatment - removal - drugs - pharmaceutical products - antibiotic residues - residues
Source separated sanitation is an innovative sanitation method designed for minimizing use of energy and clean drinking water, and maximizing reuse of water, organics and nutrients from waste water. This approach is based on separate collection and treatment of toilet wastewater (black water) and the rest of the domestic wastewater (grey water). Different characteristics of wastewater streams facilitate recovery of energy, nutrients and fresh water. To ensure agricultural or ecological reuse of liquid and solid products of source separated sanitation, the quality of these materials has to meet (future) standards, i.e. for micropollutant concentrations. Therefore the objectives of this thesis included assessment of micropollutant content of source separated sanitation products intended for resource recovery and examination of post-treatment technologies for micropollutant mitigation within source separated sanitation
The effect of harvesting on biomass production and nutrient removal in phototrophic biofilm reactors for effluent polishing
Boelee, N.C. ; Janssen, M. ; Temmink, H. ; Taparaviciute, L. ; Khiewwijit, R. ; Janoska, A. ; Buisman, C.J.N. ; Wijffels, R.H. - \ 2014
Journal of Applied Phycology 26 (2014)3. - ISSN 0921-8971 - p. 1439 - 1452.
afvalwaterbehandeling - biofilms - dikte - dichtheid - algen - biologische waterzuiveringsinstallaties - fototropie - stikstof - fosfor - verwijdering - biobased economy - waste water treatment - thickness - density - algae - biological water treatment plants - phototropism - nitrogen - phosphorus - removal - waste-water treatment - photosynthetic efficiency - chlorella-sorokiniana - microalgal biofilms - phosphorus removal - mass-transport - fresh-water - light - growth
An increasing number of wastewater treatment plants require post-treatment to remove residual nitrogen and phosphorus. This study investigated various harvesting regimes that would achieve consistent low effluent concentrations of nitrogen and phosphorus in a phototrophic biofilm reactor. Experiments were performed in a vertical biofilm reactor under continuous artificial lighting and employing artificial wastewater. Under similar conditions, experiments were performed in near-horizontal flow lanes with biofilms of variable thickness. It was possible to maintain low nitrogen and phosphorus concentrations in the effluent of the vertical biofilm reactor by regularly harvesting half of the biofilm. The average areal biomass production rate achieved a 7 g dry weight m-2 day-1 for all different harvesting frequencies tested (every 2, 4, or 7 days), corresponding to the different biofilm thicknesses. Apparently, the biomass productivity is similar for a wide range of biofilm thicknesses. The biofilm could not be maintained for more than 2 weeks as, after this period, it spontaneously detached from the carrier material. Contrary to the expectations, the biomass production doubled when the biofilm thickness was increased from 130 µm to 2 mm. This increased production was explained by the lower density and looser structure of the 2 mm biofilm. It was concluded that, concerning biomass production and labor requirement, the optimum harvesting frequency is once per week.
Microbial Removal of the Pharmaceutical Compounds Ibuprofen and Diclofenac from Wastewater
Langenhoff, A.A.M. ; Inderfurth, N.S. ; Veuskens, T. ; Schraa, G. ; Blokland, M. ; Kujawa-Roeleveld, K. ; Rijnaarts, H.H.M. - \ 2013
BioMed Research International 2013 (2013). - ISSN 2314-6133 - 9
biodegradatie - geneesmiddelen - afvalwater - afvalwaterbehandeling - bioremediëring - afvalwaterbehandelingsinstallaties - verwijdering - oppervlaktewater - geneesmiddelenresiduen - biodegradation - drugs - waste water - waste water treatment - bioremediation - waste water treatment plants - removal - surface water - drug residues - personal care products - activated carbon - batch experiments - aquatic environment - metabolites - systems - sludge - acid - transformation
Studies on the occurrence of pharmaceuticals show that the widely used pharmaceuticals ibuprofen and diclofenac are present in relevant concentrations in the environment. A pilot plant treating hospital wastewater with relevant concentrations of these pharmaceuticals was evaluated for its performance to reduce the concentration of the pharmaceuticals. Ibuprofen was completely removed, whereas diclofenac yielded a residual concentration, showing the necessity of posttreatment to remove diclofenac, for example, activated carbon. Successively, detailed laboratory experiments with activated sludge from the same wastewater treatment plant showed bioremediation potential in the treatment plant. The biological degradation pathway was studied and showed a mineralisation of ibuprofen and degradation of diclofenac. The present microbes were further studied in laboratory experiments, and DGGE analyses showed the enrichment and isolation of highly purified cultures that degraded either ibuprofen or diclofenac. This research illuminates the importance of the involved bacteria for the effectiveness of the removal of pharmaceuticals in a wastewater treatment plant. A complete removal of pharmaceuticals from wastewater will stimulate water reuse, addressing the worldwide increasing demand for clean and safe fresh water.
Evaluatie zuiveringstechniek voor verwijdering gewasbeschermingsmiddelen uit lozingswater glastuinbouw: Beoordeling van vier technieken op effectiviteit in verwijderen gewasbeschermingsmiddelen uit lozingswater en toepasbaarheid in een glastuinbouwomgeving
Ruijven, J.P.M. van; Os, E.A. van; Staaij, M. van der; Beerling, E.A.M. - \ 2013
Bleiswijk : Wageningen UR Glastuinbouw (Rapporten WUR GTB 1222)
waterzuivering - technieken - lozing - gewasbescherming - producten - verwijdering - toepassing - glastuinbouw - nederland - water treatment - techniques - disposal - plant protection - products - removal - application - greenhouse horticulture - netherlands
Gewasbeschermingsmiddelen afkomstig uit de glastuinbouw worden door waterschappen in concentraties aangetroffen die de waterkwaliteitsnormen overschrijden. Om dit probleem op te lossen en de negatieve gevolgen die dit kan hebben voor de toelating van de middelen, is onderzoek uitgevoerd naar technieken die gewasbeschermingsmiddelen uit het lozingswater van glastuinbouwbedrijven kunnen verwijderen. Op basis van een longlist van potentieel geschikte zuiveringstechnieken, zijn vier technieken geselecteerd en getest op zuiveringseffectiviteit, toepasbaarheid in de glastuinbouw, en kosten: (1) elektrochemische fl occulatie, (2) waterstofperoxide met lagedruk UV, (3) waterstofperoxide met middendruk UV en (4) ozon in combinatie met een actief koolstoffilter.
Autotrophic nitrogen removal from low strength waste water at low temperature
Hendrickx, T.L.G. ; Wang, Y. ; Kampman, C. ; Zeeman, G. ; Temmink, B.G. ; Buisman, C.J.N. - \ 2012
Water Research 46 (2012)7. - ISSN 0043-1354 - p. 2187 - 2193.
afvalwaterbehandeling - afvalwaterbehandelingsinstallaties - stikstof - verwijdering - denitrificatie - temperatuur - anaërobe behandeling - ammonium - oxidatie - energiebesparing - stedelijk afvalwater - waste water treatment - waste water treatment plants - nitrogen - removal - denitrification - temperature - anaerobic treatment - oxidation - energy saving - municipal wastewater - anaerobic ammonium oxidation - treat sewage - reactor - system
Direct anaerobic treatment of municipal waste waters allows for energy recovery in the form of biogas. A further decrease in the energy requirement for waste water treatment can be achieved by removing the ammonium in the anaerobic effluent with an autotrophic process, such as anammox. Until now, anammox has mainly been used for treating warm (>30 °C) and concentrated (>500 mg N/L) waste streams. Application in the water line of municipal waste water treatment poses the challenges of a lower nitrogen concentration (
Scenario Analysis of Nutrient Removal from Municipal Wastewater by Microalgal Biofilms
Boelee, N.C. ; Temmink, H. ; Janssen, M. ; Buisman, C.J.N. ; Wijffels, R.H. - \ 2012
Water 4 (2012)2. - ISSN 2073-4441 - p. 460 - 473.
afvalwaterbehandeling - biofilms - algen - biologische waterzuiveringsinstallaties - vergelijkend onderzoek - volgorden - haalbaarheidsstudies - heterotrofe micro-organismen - stikstof - fosfor - verwijdering - biomassa productie - biobased economy - waste water treatment - algae - biological water treatment plants - comparative research - sequences - feasibility studies - heterotrophic microorganisms - nitrogen - phosphorus - removal - biomass production - marine-phytoplankton - chemical-composition - chlorella-vulgaris - nitrate uptake - algal biofilm - growth - photobioreactor - photosynthesis
Microalgae can be used for the treatment of municipal wastewater. The application of microalgal biofilms in wastewater treatment systems seems attractive, being able to remove nitrogen, phosphorus and COD from wastewater at a short hydraulic retention time. This study therefore investigates the area requirement, achieved effluent concentrations and biomass production of a hypothetical large-scale microalgal biofilm system treating municipal wastewater. Three scenarios were defined: using microalgal biofilms: (1) as a post-treatment; (2) as a second stage of wastewater treatment, after a first stage in which COD is removed by activated sludge; and (3) in a symbiotic microalgal/heterotrophic system. The analysis showed that in the Netherlands, the area requirements for these three scenarios range from 0.32 to 2.1 m2 per person equivalent. Moreover, it was found that it was not possible to simultaneously remove all nitrogen and phosphorus from the wastewater, because of the nitrogen:phosphorus ratio in the wastewater. Phosphorus was limiting in the post-treatment scenario, while nitrogen was limiting in the two other scenarios. Furthermore, a substantial amount of microalgal biomass was produced, ranging from 13 to 59 g per person equivalent per day. These findings show that microalgal biofilm systems hold large potential as seasonal wastewater treatment systems and that it is worthwhile to investigate these systems further
Development of a low-cost alternative for metal removal from textile wastewater
Sekomo Birame, C. - \ 2012
Wageningen University. Promotor(en): Piet Lens, co-promotor(en): D.P.L. Rousseau. - Leiden : CRC Press/Balkema - ISBN 9780415641586 - 138
afvalwaterbehandeling - verwijdering - zware metalen - textielindustrie - rwanda - waste water treatment - removal - heavy metals - textile industry
Removal of micropollutants from aerobically treated grey water via ozone and activated carbon
Hernandez Leal, L. ; Temmink, B.G. ; Zeeman, G. ; Buisman, C.J.N. - \ 2011
Water Research 45 (2011)9. - ISSN 0043-1354 - p. 2887 - 2896.
afvalwaterbehandeling - waterzuivering - verontreinigende stoffen - verwijdering - afvalwater - aërobe behandeling - ozon - actieve kool - processors - vergelijkend onderzoek - waste water treatment - water treatment - pollutants - removal - waste water - aerobic treatment - ozone - activated carbon - comparative research - endocrine-disrupting chemicals - waste-water - uv filters - organic-compounds - bisphenol-a - in-vitro - pharmaceuticals - ozonation - products - vivo
Ozonation and adsorption onto activated carbon were tested for the removal micropollutants of personal care products from aerobically treated grey water. MilliQ water spiked with micropollutants (100–1600 µgL-1) was ozonated at a dosing rate of 1.22. In 45 min, this effectively removed (>99%): Four parabens, bisphenol-A, hexylcinnamic aldehyde, 4-methylbenzylidene-camphor (4MBC), benzophenone-3 (BP3), triclosan, galaxolide and ethylhexyl methoxycinnamate. After 60 min, the removal efficiency of benzalkonium chloride was 98%, tonalide and nonylphenol 95%, octocrylene 92% and 2-phenyl-5-benzimidazolesulfonic acid (PBSA) 84%. Ozonation of aerobically treated grey water at an applied ozone dose of 15 mgL-1, reduced the concentrations of octocrylene, nonylphenol, triclosan, galaxolide, tonalide and 4-methylbenzylidene-camphor to below limits of quantification, with removal efficiencies of at least 79%. Complete adsorption of all studied micropollutants onto powdered activated carbon (PAC) was observed in batch tests with milliQ water spiked with 100–1600 µgL-1 at a PAC dose of 1.25 gL-1 and a contact time of 5 min. Three granular activated carbon (GAC) column experiments were operated to treat aerobically treated grey water. The operation of a GAC column with aerobically treated grey water spiked with micropollutants in the range of 0.1–10 µgL-1 at a flow of 0.5 bed volumes (BV)h-1 showed micropollutant removal efficiencies higher than 72%. During the operation time of 1728 BV, no breakthrough of TOC or micropollutants was observed. Removal of micropollutants from aerobically treated grey water was tested in a GAC column at a flow of 2 BVh-1. Bisphenol-A, triclosan, tonalide, BP3, galaxolide, nonylphenol and PBSA were effectively removed even after a stable TOC breakthrough of 65% had been reached. After spiking the aerobically treated effluent with micropollutants to concentrations of 10–100 µgL-1, efficient removal to below limits of quantification continued for at least 1440 BV. Both ozonation and adsorption are suitable techniques for the removal of micropollutants from aerobically treated grey water.
Zieke planten snel verwijderen om nieuwe besmetting te voorkomen: Paprikaplanten met TSWV zijn aantrekkelijk voor trips
Staalduinen, J. van; Grosman, A.H. - \ 2011
Onder Glas 8 (2011)2. - p. 61 - 61.
gewasbescherming - glastuinbouw - paprika - tomatenbronsvlekkenvirus - verwijdering - kassen - teeltsystemen - groenten - plant protection - greenhouse horticulture - sweet peppers - tomato spotted wilt virus - removal - greenhouses - cropping systems - vegetables
Recent onderzoek naar mogelijkheden om de verspreiding van tomatenbronsvlekkenvirus in kassen met paprika te beperken, heeft nieuwe inzichten opgeleverd. Besmette planten blijken zeer aantrekkelijk te zijn voor trips, veruit de belangrijkste verspreider van het virus. Het is daarom zaak om besmette planten zo snel mogelijk te ruimen en de tripspopulatie onder de duim te houden
Effectgerichte aanpak verwijdering P uit bodem- en slootwater duinzandgrond
Belder, P. ; Kool, S.A.M. de; Jansen, S. ; Stuurman, R. ; Koopmans, G.F. ; Chardon, W.J. - \ 2010
BloembollenVisie 2010 (2010)207. - ISSN 1571-5558 - p. 20 - 20.
zuiveren - fosfaat - verwijdering - eu regelingen - tests - zuiveringsinstallaties - oppervlaktewaterkwaliteit - waterzuivering - purification - phosphate - removal - eu regulations - purification plants - surface water quality - water treatment
Op bloembollenpercelen bij Egmond a/d Hoef worden twee zuiveringsmethoden getest om fosfaat te verwijderen uit bodem en slootwater. Het doel is het water te zuiveren van fosfaat om daarmee te voldoen aan de Europese Regelgeving voor de kwaliteit van oppervlaktewater.
Hydrogen bonding in the recovery of phenols and methyl-t-butyl ether : molecular modeling and calorimetry
Cuypers, R. - \ 2010
Wageningen University. Promotor(en): Han Zuilhof; Ernst Sudhölter. - [S.l. : S.n. - ISBN 9789085857754 - 189
afvalwaterbehandeling - verwijdering - fenol - ethers - derivaten - harsen - extractie - waste water treatment - removal - phenol - derivatives - resins - extraction
The purification of waste water is very important, for clean potable water is a common good and a necessity. Surface water purification is nowadays carried out on a massive industrial scale, and clean water is at our disposal virtually everywhere and always. However, cleaning industrial waste water can be a difficult task. Although apolar and slightly polar compounds can be removed from water relatively easily e.g. by extraction to an apolar phase, more polar pollutants like phenol and methyl-tert-butyl ether (MTBE), the two main compounds that this thesis deals with, cannot be removed as easily. A more effective method is therefore needed to clean water that is contaminated with either phenol or MTBE.
Solvent-Impregnated Resins (SIRs) are porous polymer beads containing apolar organic extractant liquids. They are used as three-phase separation systems. When brought into contact with a SIR, a solute will preferentially partition from the aqueous phase into the impregnated solvent phase. A drawback to the use of solely the organic extraction liquid in SIRs is the limited solubility of more polar compounds like phenols and ethers in such a medium. In order to enhance extraction, complex-forming extractants can be added to the organic solvent. By means of complex formation inside the organic solvent, the overall equilibrium distribution can be shifted towards the SIR, with a concomitant enhancement of the extraction efficiency. A tight binding of the pollutant molecules to the extractant will eventually ensure high distribution coefficients. However, a moderate binding strength would enable a relatively easy regeneration of the complexing agent after a binding event, enabling multiple uses of the same compound.
In this thesis hydrogen-bond (H-bond) complexation, a specific and strong yet reversible way of binding is investigated for phenol recovery and MTBE recovery from aqueous environments, involving the use of organic complexing agents that can be used inside the SIR to enhance the extraction. Potentially interesting compounds were investigated on a molecular scale by quantum chemical modeling methods and subsequent synthesis and physical characterization by primarily calorimetric means. H-bond complex formation has been evaluated and the important parameters determining the binding process have been described.
After a general introduction in Chapter 1, Chapters 2 through 4 describe phenol complexation by several different classes of complexing agents. In Chapter 2, the binding of phenol and thiophenol by phosphine oxides, phosphates, and their thio-analogs was investigated. Modeling experiments, isothermal titration calorimetry (ITC) measurements, and liquid-liquid extraction experiments showed that, in principle, the binding affinity of the oxide compounds for phenol is high, whereas the sulfide compounds show only low affinity. In particular, the binding behavior of tri-n-octylphosphine oxide towards phenol and a series of electron-withdrawing group (EWG)-substituted phenols was studied, both in the presence and absence of water in the system. It was found that the presence of water in the system – as can be expected in industrial applications – yields lower binding affinities by as much as 60 %, but the binding stoichiometry remained specific and 1 : 1 complexes were still found. Electronic and steric effects were shown to play an important role in phenol binding in the investigated environment.
In Chapter 3, these investigations were extended to the modeling of the full homologous series of mono-, di- and tri-substituted phosphine oxides and phosphates and their thio-analogs. Different modeling methods were used to investigate both structural and electronic elements. Dimethylphosphate was found to form the strongest complexes to the investigated phenols, but because this compound forms very strong homo-dimers in solution it cannot be used as an effective extractant. The SCS-MP2 method, that was relatively unexplored for H-bonding until now, was found to yield very accurate energy predictions, whereas the CBS-Q method was found to predict false binding affinities. Solvent effects are shown to immensely influence the binding behavior.
Another, even stronger group of H-bond acceptors, amine-N-oxides, was investigated as described in Chapter 4. The binding properties for phenol and thiophenol with three different amine-N-oxides yielded very high binding affinities (up to 30 times higher than for the phosphine oxide compounds). Introduction of EWGs in the amine-N-oxides was shown to yield markedly lower binding affinities towards phenols, providing a handle to fine-tune the interaction and facilitating easier regeneration of the complexing agent in future SIR applications. Solvent effects and the influence of water in the system were investigated, and it was shown that they both influence the phenol binding strength. The results in Chapters 2 through 4 show that phosphates, phosphine oxides, and amine-N-oxides could all be used in future SIR extraction systems, and the choice between these classes of compounds can be made based on more detailed considerations.
MTBE binding by several complexing agents was described in Chapter 5. A detailed modeling study of a number of different substituted phenols for MTBE binding was carried out, and the influence of solvents on the binding behavior was investigated, using a.o. the recently developed M06-2X functional and SMD solvent model. The investigated complexing agents were found to show moderate binding affinities to MTBE with binding strengths being closely linked to the acidity of the extractant. Steric effects and a proper consideration of entropic effects are also found to be important to yield successful binding of MTBE. In combination with the existing MTBE distribution coefficient for apolar phases, these moderate binding affinities were found to be able to enhance extraction, in principle, up to the point where it becomes industrially relevant to use such extractants in SIR-based extractions.
Finally, in Chapter 6 the performed research is reviewed, and conclusions, recommendations and a wider perspective for future scientific challenges are given.

Verkenning mogelijkheden voor verwijderen Japanse oesters in recreatiezones Grevelingenmeer
Wijsman, J.W.M. ; Perdon, K.J. ; Mesel, I.G. de - \ 2010
Yerseke : IMARES (Rapport / Wageningen IMARES C051/10) - 25
recreatiegebieden - bezoekers - wonden - oesters - schelpen - verwijdering - grevelingen - effecten - amenity and recreation areas - visitors - wounds - oysters - shells - removal - effects
De wildgroei van oesters in de recreatiegebieden van het Grevelingenmeer leidt tot overlast voor surfers en badgasten die zich regelmatig verwonden aan de scherpe schelpen. In dit onderzoek is er gekeken naar de mogelijkheden die er zijn om oesters te verwijderen uit de recreatiezones bij de Brouwersdam (Kabbelaarsbank, De Punt en Westrepart).
Policies to Encourage the Development of Water Sanitation Technology
Euverink, G.J.W. ; Temmink, B.G. ; Rozendal, R.A. ; Buisman, C.J.N. - \ 2009
In: Water Policy in the Netherlands, Integrated Management in a Densely Populated Delta / Reinhard, S., Folmer, H., Washington, DC, USA : RFF PRESS (Issues in Water Resource Policy ) - ISBN 9781933115733 - p. 139 - 151.
afvalwater - afvalwaterbehandeling - technologie - stikstof - verwijdering - fosfaten - terugwinning - bioreactoren - scheiding - waste water - waste water treatment - technology - nitrogen - removal - phosphates - recovery - bioreactors - separation
This chapter examines innovations in water technology, policies to develop technologies that will contribute to a sustainalbe economy, and the introduction of the new concepts to society. We discuss our views on how wastewater treatment may be performed in the future in such a way that the WFD guidelines are met economically. Preventing the mixing and diluting of different wastewater streams would enable reuse of valuable components (energie, minerals, and water). This chapter also decribes nitrogen removal and recovery techniques that can convert ammonia and nitrates into dinitrogen gas. At present, industrial ammonia synthesis from dinitrogen gas is more economically feasible than reuse of ammonia from wastewater. Chemical and biological methods to remove phosphorus are examined as well. Phosphorus is a good potential target for reuse, as the natural reserves of the ore are limited. Removal of phophorus from wastewater would also decrease eutrophication of natural water. Membrane bioreactors are very promising in the treatment of special industrial wastewater or enhanced treatment of municipal wastewater. The chapter then looks at bioelectrochemical conversion processes-microbial fuel cells and biocatalyzed electrolysis-new techniques to recover energy from wastewater that require less erngy than conventional techniques. Therefore, more energy is left in the wastewater and conversion into methane, electricity, or hydrogen becomes possible
Nitrous oxide emission during wastewater treatment
Kampschreur, M.J. ; Temmink, B.G. ; Kleerebezem, R. ; Jetten, M.S.M. ; Loosdrecht, M.C.M. - \ 2009
Water Research 43 (2009)17. - ISSN 0043-1354 - p. 4093 - 4103.
denitrificatie - broeikaseffect - stikstofoxide - nitrificatie - distikstofmonoxide - afvalwaterbehandeling - broeikasgassen - stikstof - verwijdering - denitrification - greenhouse effect - nitric oxide - nitrification - nitrous oxide - waste water treatment - greenhouse gases - nitrogen - removal - biological phosphorus removal - denitrifying activated-sludge - sequencing batch reactor - treatment-plant - alcaligenes-faecalis - dinitrogen oxide - n2o production - simultaneous nitrification - aerobic denitrification - autotrophic nitrifiers
Nitrous oxide (N2O), a potent greenhouse gas, can be emitted during wastewater treatment, significantly contributing to the greenhouse gas footprint. Measurements at lab-scale and full-scale wastewater treatment plants (WWTPs) have demonstrated that N2O can be emitted in substantial amounts during nitrogen removal in WWTPs, however, a large variation in reported emission values exists. Analysis of literature data enabled the identification of the most important operational parameters leading to N2O emission in WWTPs: (i) low dissolved oxygen concentration in the nitrification and denitrification stages, (ii) increased nitrite concentrations in both nitrification and denitrification stages, and (iii) low COD/N ratio in the denitrification stage. From the literature it remains unclear whether nitrifying or denitrifying microorganisms are the main source of N2O emissions. Operational strategies to prevent N2O emission from WWTPs are discussed and areas in which further research is urgently required are identified
Selective recovery of nickel over iron from a nickel-iron solution using microbial sulfate reduction in a gas-lift bioreactor
Bijmans, M.F.M. ; Helvoort, P.J. van; Dar, S. ; Dopson, M. ; Lens, P.N.L. ; Buisman, C.J.N. - \ 2009
Water Research 43 (2009)3. - ISSN 0043-1354 - p. 853 - 861.
mijnbouw - metallurgie - mijnafval - slib - waterstof - ijzer - nikkel - bioreactoren - elektroforese - sulfaatreductie - slibzuivering - verwijdering - mining - metallurgy - mine tailings - sludges - hydrogen - iron - nickel - bioreactors - electrophoresis - sulfate reduction - sludge treatment - removal - gradient gel-electrophoresis - sulfide precipitation - metal precipitation - heavy-metals - soils - water - ores
Process streams with high concentrations of metals and sulfate are characteristic for the mining and metallurgical industries. This study aims to selectively recover nickel from a nickel-iron-containing solution at pH 5.0 using a single stage bioreactor that simultaneously combines low pH sulfate reduction and metal-sulfide formation. The results show that nickel was selectively precipitated in the bioreactor at pH 5.0 and the precipitates consisted of >or=83% of the nickel content. The nickel-iron precipitates were partly crystalline and had a metal/sulfur ratio of 1, suggesting these precipitates were NiS and FeS. Experiments focusing on nickel recovery at pH 5.0 and 5.5 reached a recovery of >99.9%, resulting in a nickel effluent concentration
Combined carbon and nitrogen removal in integrated anaerobic/anoxic sludge bed reactors for the treatment of domestic sewage
Kassab, G. - \ 2009
Wageningen University. Promotor(en): Jules van Lier, co-promotor(en): B. Klapwijk; M. Fayyad. - [S.l. : S.n. - ISBN 9789085853886 - 130
rioolwater - rioolslib - bioreactoren - anaërobe behandeling - anaërobe afbraak - denitrificatie - afvalwaterbehandeling - stikstof - verwijdering - koolstof - sewage - sewage sludge - bioreactors - anaerobic treatment - anaerobic digestion - denitrification - waste water treatment - nitrogen - removal - carbon
The main objective of this research is to assess the applicability and effectiveness of integrating anaerobic digestion and denitrification processes in a single sludge system. The integrated concept is of particular interest for the treatment of highstrength domestic wastewater and is accomplished by means of a sequential anaerobic-aerobic system. The anaerobic pre-treatment can consist of a single anaerobic stage or two anaerobic stages, conditioned mainly by the wastewater characteristics, the prevailing ambient temperatures and the scale of application
Selenate removal in methanogenic and sulfate-reducing upflow anaerobic sludge bed reactors
Lenz, M. ; Hullebusch, E.D. van; Hommes, G. ; Corvini, P.F.X. ; Lens, P.N.L. - \ 2008
Water Research 42 (2008)8-9. - ISSN 0043-1354 - p. 2184 - 2194.
afvalwaterbehandeling - bioreactoren - slib - selenium - verwijdering - efficiëntie - biologische filtratie - slibzuivering - sulfaatreductie - waste water treatment - bioreactors - sludges - removal - efficiency - biological filtration - sludge treatment - sulfate reduction - acid-mine drainage - granular sludge - elemental selenium - respiring bacteria - waste-water - se - reduction - sediments - coal - particulate
This paper evaluates the use of upflow anaerobic sludge bed (UASB) bioreactors (30 degrees C, pH = 7.0) to remove selenium oxyanions from contaminated waters (790 mu g Se L-1) under methanogenic and sulfate-reducing conditions using lactate as electron donor. One UASB reactor received sulfate at different sulfate to selenate ratios, while another UASB was operated under methanogenic conditions for 132 days without sulfate in the influent. The selenate effluent concentrations in the sulfate-reducing and methanogenic reactor were 24 and 8 mu gSeL(-1), corresponding to removal efficiencies of 97% and 99%, respectively. X-ray diffraction (XRD) analysis and sequential extractions showed that selenium was mainly retained as elemental selenium in the biomass. However, the total dissolved selenium effluent concentrations amounted to 73 and 80 mu gSeL(-1), respectively, suggesting that selenate was partly converted to another selenium compound, most likely colloidally dispersed Sea nanoparticles. Possible intermediates of selenium reduction (selenite, dimethylselenide, dimethyldiselenide, H2Se) could not be detected. Sulfate reducers removed selenate at molar excess of sulfate to selenate (up to a factor of 2600) and elevated dissolved sulfide concentrations (up to 168mgL(-1)), but selenium removal efficiencies were limited by the applied sulfate-loading rate. in the methanogenic bioreactor, selenate and dissolved selenium removal were independent of the sulfate load, but inhibited by sulfide (101 mg L-1). The selenium removal efficiency of the methanogenic UASB abruptly improved after 58 days of operation, suggesting that a specialized selenium-converting population developed in the reactor. This paper demonstrates that both sulfate-reducing and methanogenic UASB reactors can be applied to remove selenate from contaminated natural waters and anthropogenic waste streams, e.g. agricultural drainage waters, acid mine drainage and flue gas desulfurization bleeds.
Moerasbufferstroken: potenties voor nutriëntenverwijdering en economisch rendement - een case study in westelijk Noord-Brabant
Antheunisse, A.M. ; Bos, E.J. ; Verhoeven, L. ; Hefting, M.M. - \ 2008
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 41 (2008)20. - ISSN 0166-8439 - p. 49 - 52.
waterkwaliteit - oppervlaktewater - verontreinigingsbeheersing - waterbeheer - slootkanten - voedingsstoffen - verwijdering - landbouwgrond - nederland - kosten-batenanalyse - begroeide stroken - oppervlaktewaterkwaliteit - bufferzones - water quality - surface water - pollution control - water management - ditch banks - nutrients - removal - agricultural land - netherlands - cost benefit analysis - vegetated strips - surface water quality - buffer zones
Diffuse belasting van het oppervlaktewater met nutriënten vormt een probleem voor het waterbeheer in Nederland. De inzet van ecotechnologische maatregelen kan bijdragen aan de reductie van de emissies. Met name moerasbufferstroken, waarbij het te zuiveren water in contact komt met de bovenste bodemlagen, laten een hoge verwijdering zien. In dit artikel staat een onderzoek centraal naar de werking van een moerasbufferstrook langs de Strijbeekse beek (Noord-Brabant), waarbij het drainagewater direct in de bufferstrook uitkomt, én het economische rendement van zo’n systeem. De verwijdering van stikstof blijkt beperkt door de hoge kweldruk en daaruitvolgende lage infiltratie van drainagewater. De verwijdering van fosfaten is juist hoog vanwege de hoge adsorptiecapaciteit van de bodem door de aanwezigheid van ijzerionen. Met een alternatieve inrichting en beheer is het mogelijk ook de verwijderingsefficiëntie voor stikstof te verhogen. Uit de economische analyse komt naar voren dat de bufferstrook van 350 meter niet rendeert. Indien bufferstroken met een gezamenlijke lengte van 6,5 kilometer zouden worden aangelegd, zijn meer maatschappelijke baten te verwachten, maar dan nog zijn deze niet voldoende om op te wegen tegen de kosten van uit productie genomen landbouwgrond
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