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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    Future water quality monitoring - Adapting tools to deal with mixtures of pollutants in water resource management
    Altenburger, R. ; Ait-Aissa, S. ; Antczak, P. ; Backhaus, T. ; Barcelo, D. ; Seiler, T. ; Brion, F. ; Focks, A. - \ 2015
    Science of the Total Environment 512-513 (2015). - ISSN 0048-9697 - p. 540 - 551.
    effect-directed analysis - environmental risk-assessment - tandem mass-spectrometry - community tolerance pict - waste-water - estrogenic compounds - surface waters - conceptual-framework - organic-chemicals - zebrafish embryos
    Environmental quality monitoring of water resources is challenged with providing the basis for safeguarding the environment against adverse biological effects of anthropogenic chemical contamination from diffuse and point sources. While current regulatory efforts focus on monitoring and assessing a few legacy chemicals, many more anthropogenic chemicals can be detected simultaneously in our aquatic resources. However, exposure to chemical mixtures does not necessarily translate into adverse biological effects nor clearly shows whether mitigation measures are needed. Thus, the question which mixtures are present and which have associated combined effects becomes central for defining adequate monitoring and assessment strategies. Here we describe the vision of the international, EU-funded project SOLUTIONS, where three routes are explored to link the occurrence of chemical mixtures at specific sites to the assessment of adverse biological combination effects. First of all, multi-residue target and non-target screening techniques covering a broader range of anticipated chemicals co-occurring in the environment are being developed. By improving sensitivity and detection limits for known bioactive compounds of concern, new analytical chemistry data for multiple components can be obtained and used to characterise priority mixtures. This information on chemical occurrence will be used to predict mixture toxicity and to derive combined effect estimates suitable for advancing environmental quality standards. Secondly, bioanalytical tools will be explored to provide aggregate bioactivity measures integrating all components that produce common (adverse) outcomes even for mixtures of varying compositions. The ambition is to provide comprehensive arrays of effect-based tools and trait-based field observations that link multiple chemical exposures to various environmental protection goals more directly and to provide improved in situ observations for impact assessment of mixtures. Thirdly, effect-directed analysis (EDA) will be applied to identify major drivers of mixture toxicity. Refinements of EDA include the use of statistical approaches with monitoring information for guidance of experimental EDA studies. These three approaches will be explored using case studies at the Danube and Rhine river basins as well as rivers of the Iberian Peninsula. The synthesis of findings will be organised to provide guidance for future solution-oriented environmental monitoring and explore more systematic ways to assess mixture exposures and combination effects in future water quality monitoring.
    "Logistic analysis of algae cultivation"
    Slegers, P.M. ; Leduc, S. ; Wijffels, R.H. ; Straten, G. van; Boxtel, A.J.B. van - \ 2015
    Bioresource Technology 179 (2015). - ISSN 0960-8524 - p. 314 - 322.
    biofuel production - co2 capture - waste-water - microalgae - scale - availability - economics - biomass - biogas
    Energy requirements for resource transport of algae cultivation are unknown. This work describes the quantitative analysis of energy requirements for water and CO2 transport. Algae cultivation models were combined with the quantitative logistic decision model ‘BeWhere’ for the regions Benelux (Northwest Europe), southern France and Sahara. For photobioreactors, the energy consumed for transport of water and CO2 turns out to be a small percentage of the energy contained in the algae biomass (0.1–3.6%). For raceway ponds the share for transport is higher (0.7–38.5%). The energy consumption for transport is the lowest in the Benelux due to good availability of both water and CO2. Analysing transport logistics is still important, despite the low energy consumption for transport. The results demonstrate that resource requirements, resource distribution and availability and transport networks have a profound effect on the location choices for algae cultivation.
    The SOLUTIONS project: Challenges and responses for present and future emerging pollutants in land and water resources management
    Brack, W. ; Altenburger, R. ; Schuurmann, G. ; Krauss, M. ; Brink, P.J. van den - \ 2015
    Science of the Total Environment 503-504 (2015). - ISSN 0048-9697 - p. 22 - 31.
    effect-directed analysis - community tolerance pict - waste-water - risk-assessment - environmental contamination - organic micropollutants - chemical footprint - complex-mixtures - treatment plants - stress-response
    SOLUTIONS (2013 to 2018) is a European Union Seventh Framework Programme Project (EU-FP7). The project aims to deliver a conceptual framework to support the evidence-based development of environmental policies with regard to water quality. SOLUTIONS will develop the tools for the identification, prioritisation and assessment of those water contaminants that may pose a risk to ecosystems and human health. To this end, a new generation of chemical and effect-based monitoring tools is developed and integrated with a full set of exposure, effect and risk assessment models. SOLUTIONS attempts to address legacy, present and future contamination by integrating monitoring and modelling based approaches with scenarios on future developments in society, economy and technology and thus in contamination. The project follows a solutions-oriented approach by addressing major problems of water and chemicals management and by assessing abatement options. SOLUTIONS takes advantage of the access to the infrastructure necessary to investigate the large basins of the Danube and Rhine as well as relevant Mediterranean basins as case studies, and puts major efforts on stakeholder dialogue and support. Particularly, the EU Water Framework Directive (WFD) Common Implementation Strategy (CIS) working groups, International River Commissions, and water works associations are directly supported with consistent guidance for the early detection, identification, prioritisation, and abatement of chemicals in the water cycle. SOLUTIONS will give a specific emphasis on concepts and tools for the impact and risk assessment of complex mixtures of emerging pollutants, their metabolites and transformation products. Analytical and effect-based screening tools will be applied together with ecological assessment tools for the identification of toxicants and their impacts. The SOLUTIONS approach is expected to provide transparent and evidence-based candidates or River Basin Specific Pollutants in the case study basins and to assist future review of priority pollutants under the WFD as well as potential abatement options.
    Effects of diet composition and ultrasound treatment on particle size distribution and carbon bioavailability in feces of rainbow trout
    Meriac, A. ; Tilburg, T. van; Eding, E.H. ; Kamstra, A. ; Schrama, J.W. ; Verreth, J.A.J. - \ 2015
    Aquacultural Engineering 65 (2015). - ISSN 0144-8609 - p. 10 - 16.
    recirculating aquaculture systems - activated-sludge - anaerobic-digestion - waste-water - feed - fish - denitrification - digestibility - pretreatment - sonication
    The effect of a high and low non-starch polysaccharide diet (HNSP and LNSP diet) and ultrasound treatment on particle size distribution and carbon bioavailability in fecal waste of rainbow trout (Oncorynchus mykiss) was studied. Feces were collected from four flow-through fish tanks, two tanks fed the HNSP diet and two the LNSP diet. The collected feces were sonicated (disintegrated) in duplicate with high-intensity (0.6 W/ml), low-frequency (f = 20 Hz) ultrasound at five different energy levels (0.6 W/ml for 0, 0.25, 1, 4, and 16 min). The particle size distribution of the treated feces samples was measured by wet sieving (1000, 500, 200, 100, 63, 36, 1.2 µm screen size) and total suspended solids (TSS) measurement. Carbon bioavailability in sonicated fecal waste samples was determined with oxygen uptake rate (OUR) tests. The results showed that: (1) feces from the HNSP diet contained significant more particulate material and bigger particles; (2) carbon bioavailability was almost three times higher in untreated LNSP feces when compared with HNSP feces; (3) almost 50% of HNSP feces could have been recovered on a microscreen of 36 µm after wet sieving, whereas it was only 10% for LNSP feces; (4) the production of small particles (1.2–36 µm), which could pass a drum filter screen and potentially accumulate in RAS, was approximately 50 g/kg feed, showing no significant differences between diets; (5) sonication increased fecal dry matter below 36 µm (p = 0.015), but it had no significant effect on the median particle size; (6) sonication increased carbon bioavailability with 7–10% for the HNSP feces (p = 0.037); (7) fecal particles withstood up to 16 min sonication at an intensity of 0.6 W/ml and a frequency of 20 Hz corresponding to specific energy input of 20,000 kJ/kg DM without major changes in particle size distribution. The results of this study indicate that the applied ultrasound treatment of fecal waste is not an effective method to increase short-term carbon bioavailability.
    Sulfate reduction in a hydrogen fed bioreactor operated at haloalkaline conditions
    Sousa, J.A.B. ; Plugge, C.M. ; Stams, A.J.M. ; Bijmans, M.F.M. - \ 2015
    Water Research 68 (2015). - ISSN 0043-1354 - p. 67 - 76.
    gas-lift reactor - sp-nov. - reducing bacteria - high salinity - soda lakes - uasb reactors - waste-water - gen. nov. - sp. nov - bed
    Biological sulfate reduction is used as a biotechnological process to treat sulfate rich streams. However, application of biological sulfate reduction at high pH and high salinity using H2 was not thoroughly investigated before. In this work the sulfate reduction activity, biomass growth, microbial community and biomass aggregation were investigated in a H2-fed gas lift bioreactor at haloalkaline conditions. The process was characterized by low sulfate reduction volumetric rates due to slow growth and lack of biomass aggregation. Apparently, the extreme conditions and absence of organic compounds prevented the formation of stable aggregates. The microbial community analysis revealed a low abundance of known haloalkaliphilic sulfate reducers and presence of a Tindallia sp. The identified archaea were related to Methanobacterium alcaliphilum and Methanocalculus sp. The biomass did not attach to metal sulfides, calcite and magnesite crystals. However, biofilm formation on the glass bioreactor walls showed that attachment to glass occurs.
    Removal of nitrogen by Algal Turf Scrubber Technology in recirculating aquaculture system
    Valeta, J. ; Verdegem, M.C.J. - \ 2015
    Aquaculture Research 46 (2015)4. - ISSN 1355-557X - p. 945 - 951.
    fresh-water algae - waste-water - ecosystems
    Ongoing research in recirculation aquaculture focuses on evaluating and improving the purification potential of different types of filters. Algal Turf Scrubber (ATS) are special as they combine sedimentation and biofiltration. An ATS was subjected to high nutrient loads of catfish effluent to examine the effect of total suspended solids (TSS), sludge accumulation and nutrient loading rate on total ammonia nitrogen (TAN), nitrite and nitrate removal. Nutrient removal rates were not affected at TSS concentration of up to 0.08 g L-1 (P > 0.05). TAN removal rate was higher (0.656 ± 0.088 g m-² day-1 TAN) in young biofilm than (0.302 ± 0.098 g m-² day-1 TAN) in mature biofilm at loading rates of 3.81 and 3.76 g m-² day-1 TAN (P <0.05), respectively, which were considered close to maximum loading. TAN removal increased with TAN loading, which increased with hydraulic loading rate. There was no significant difference in removal rate for both nitrite and nitrate between young and mature biofilms (P > 0.05). The ATS ably removed nitrogen at high rates from catfish effluent at high loading rates. ATS-based nitrogen removal exhibits high potential for use with high feed loads in intensive aquaculture.
    Biotechnologies for critical raw material recovery from primary and secondary sources: R&D priorities and future perspectives
    Hennebel, T. ; Boon, N. ; Maes, S. ; Lenz, M. - \ 2015
    New Biotechnology 32 (2015)1. - ISSN 1871-6784 - p. 121 - 127.
    acid-mine drainage - heavy-metals - waste-water - selective precipitation - bacterial surfaces - nanoparticles - selenium - removal - copper - biosorption
    Europe is confronted with an increasing supply risk of critical raw materials. These can be defined as materials of which the risks of supply shortage and their impacts on the economy are higher compared to most of other raw materials. Within the framework of the EU Innovation Partnership on raw materials Initiative, a list of 14 critical materials was defined, including some bulk metals, industrial minerals, the platinum group metals and rare earth elements. To tackle the supply risk challenge, innovation is required with respect to sustainable primary mining, substitution of critical metals, and urban mining. In these three categories, biometallurgy can play a crucial role. Indeed, microbe–metal interactions have been successfully applied on full scale to win materials from primary sources, but are not sufficiently explored for metal recovery or recycling. On the one hand, this article gives an overview of the microbial strategies that are currently applied on full scale for biomining; on the other hand it identifies technologies, currently developed in the laboratory, which have a perspective for large scale metal recovery and the needs and challenges on which bio-metallurgical research should focus to achieve this ambitious goal.
    Alternating electric field fluidized bed disinfection performance with different types of granular activated carbon
    Racyte, J. ; Yntema, D.R. ; Kazlauskaite, L. ; DuBois, A. ; Bruning, H. ; Rijnaarts, H.H.M. - \ 2014
    Separation and Purification Technology 132 (2014). - ISSN 1383-5866 - p. 70 - 76.
    waste-water - 3-dimensional electrodes - bacteria - particles - adhesion - viability - removal - system - point - reuse
    The removal of pathogens from effluents is important to promote the reuse of these water resources and safeguarding human health, especially in water scarce areas worldwide. Previously a proof-of-principle of a method for water disinfection consisting of fluidized bed electrodes (FBE) with RX3 EXTRA granular activated carbon (GAC) and a low strength alternating electric field (AC field) in radio frequency range (80–200 kHz) was published. In the study presented here we investigated the mechanistic role of 10 different types of GAC in radio frequency FBE disinfection with Escherichiacoli YMc10 as the model microorganism. The disinfection performances with only GAC, and GAC combined with an AC field were quantified. Seven GACs showed poor to intermediate and three GACs (Norit RB3 (2.7 Log CFU E. coli decrease), Sorbonorit 3 (2.8 Log CFU E. coli decrease) and RX3 EXTRA (3.4 Log CFU E. coli decrease)) showed substantial disinfection in FBE. The results suggest a relation between the pHpzc of the GAC and the disinfection performance. Disinfection performance increased with bigger particle size and decreasing conductivity of tested GACs. We conclude that these physico-chemical and physical properties of GAC are important factors controlling the disinfection performance of these type FBE systems.
    Validation of a qualitative screening method for pesticides in fruits and vegetables by gas chromatography quadrupole-time of flight mass spectrometry with atmospheric pressure chemical ionization
    Portoles, T. ; Mol, J.G.J. ; Sancho, J.V. ; Lopez, F.J. ; Hernandez, F. - \ 2014
    Analytica Chimica Acta 838 (2014). - ISSN 0003-2670 - p. 76 - 85.
    residue analysis - transformation products - multiclass pesticides - waste-water - identification - food - quantification - elucidation - extraction - advantages
    A wide-scope screening method was developed for the detection of pesticides in fruit and vegetables. The method was based on gas chromatography coupled to a hybrid quadrupole time-of-flight mass spectrometer with an atmospheric pressure chemical ionization source (GC-(APCI)QTOF MS). A non-target acquisition was performed through two alternating scan events: one at low collision energy and another at a higher collision energy ramp (MSE). In this way, both protonated molecule and/or molecular ion together with fragment ions were obtained in a single run. Validation was performed according to SANCO/12571/2013 by analysing 20 samples (10 different commodities in duplicate), fortified with a test set of 132 pesticides at 0.01, 0.05 and 0.20 mg kg-1. For screening, the detection was based on one diagnostic ion (in most cases the protonated molecule). Overall, at the 0.01 mg kg-1 level, 89% of the 2620 fortifications made were detected. The screening detection limit for individual pesticides was 0.01 mg kg-1 for 77% of the pesticides investigated. The possibilities for identification according to the SANCO criteria, requiring two ions with a mass accuracy =±5 ppm and an ion-ratio deviation =±30%, were investigated. At the 0.01 mg kg-1 level, identification was possible for 70% of the pesticides detected during screening. This increased to 87% and 93% at the 0.05 and 0.20 mg kg-1 level, respectively. Insufficient sensitivity for the second ion was the main reason for the inability to identify detected pesticides, followed by deviations in mass accuracy and ion ratios.
    Identification of Unknown Microcontaminants in Dutch River Water by Liquid Chromatography-High Resolution Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy.
    Leerdam, J.A. van; Vervoort, J.J.M. ; Stroomberg, G. ; Voogt, P. de - \ 2014
    Environmental Science and Technology 48 (2014)21. - ISSN 0013-936X - p. 12791 - 12799.
    accurate-mass - degradation-products - phenolic resins - waste-water - transformation products - polar pesticides - surface-water - catalyst type - contaminants - formaldehyde
    In the past decade during automated surface water monitoring in the river Meuse at border station Eijsden in The Netherlands, a set of unknown compounds were repeatedly detected by online liquid chromatography-diode-array detection in a relatively high signal intensity. Because of the unknown nature of the compounds, the consequently unknown fate of this mixture in water treatment processes, the location being close to the water inlet of a drinking water supply company and their possible adverse public health effects, it was deemed necessary to elucidate the identity of the compounds. No data are available for the occurrence of these unknowns at downstream locations. After concentration and fractionation of a sample by preparative Liquid Chromatography, identification experiments were performed using Liquid Chromatography-High Resolution Mass Spectrometry (LC-HR-MS) combined with High Resolution Nuclear Magnetic Resonance Spectroscopy (HR-NMR). Accurate mass determination of the unknown parent compound and its fragments obtained in MS/MS provided relevant information on the elemental composition of the unknown compounds. With the use of NMR techniques and the information about the elemental composition, the identity of the compounds in the different sample fractions was determined. Beside some regularly detected compounds in surface water, like caffeine and bisphenol-S, five dihydroxydiphenylmethane isomers were identified. The major unknown compound was identified as 4,4'-dihydroxy-3,5,3',5'-tetra(hydroxymethyl)diphenylmethane. This compound was confirmed by analysis of the pure reference compound. This is one of the first studies that employs the combination of high resolution MS with NMR for identification of truly unknown compounds in surface waters at the µg/L level. Five of the seven identified compounds are unexpected and not contained in the CAS database, while they can be presumed to be products generated during the production of resins.
    Long-term acclimation of anaerobic sludges for high-rate methanogenesis from LCFA
    Silva, S.A. ; Cavaleiro, A.J. ; Pereira, M.A. ; Stams, A.J.M. ; Alves, M.M. ; Sousa, D.Z. - \ 2014
    Biomass and Bioenergy 67 (2014). - ISSN 0961-9534 - p. 297 - 303.
    chain fatty-acids - oleic-acid - oxidizing bacteria - methane production - waste-water - digestion - lipids - quantification - hybridization - accumulation
    Inhibition of methanogens by long chain fatty acids (LCFA) and the low numbers of LCFA-degrading bacteria are limitations to exploit biogas production from fat-rich wastewaters. Generally reactors fail due to excessive LCFA accumulation onto the sludge. Here, long-term acclimation and bioaugmentation with a LCFA-degrading coculture were hypothesized as strategies to enhance methanogenic conversion of these compounds. Anaerobic sludges previously exposed to LCFA for more than 100 days converted a specific biomass-associated substrate of (3.2 ± 0.1) kg·kg-1 with very short lag phases (
    Microbacter margulisiae gen. nov., sp. nov., a novel propionigenic bacterium isolated from sediments of an acid rock drainage pond
    Sanchez Andrea, I. ; Luis Sanz, J. ; Stams, A.J.M. - \ 2014
    International Journal of Systematic and Evolutionary Microbiology 64 (2014)12. - ISSN 1466-5026 - p. 3936 - 3942.
    treating mine drainage - sulfate reduction - plant residue - waste-water - field soil - environment
    A novel anaerobic propionigenic bacterium, strain ADRIT, was isolated from sediment of an acid rock drainage environment (Tinto River, Spain). Cells were small (0.4-0.6 x 1-1.7 µm), non-motile and non-spore forming rods. Cells possessed a Gram-negative cell wall structure and were vancomycin resistant. The strain ADRIT utilized yeast extract and various sugars as substrates and formed propionate, lactate and acetate as major fermentation products. The optimum growth temperature was 30 °C and the optimum pH was 6.5, but strain ADRIT was able to grow at pH as low as 3.0. Oxidase, indole formation, and urease and catalase activities were negative. Aesculin and gelatin were hydrolysed. The predominant CFAs of strain ADRIT were anteiso-C15¿:¿0 (30.3%), iso-C15:0 (29.1%) and iso-C17:0 3-OH (14.9%). Major menaquinones were MK-8 (52%) and MK-9 (48%). The genomic DNA G+C content was 39.9 mol%. Phylogenetically, strain ADRIT was affiliated to the Porphyromonadaceae family of Bacteroidetes phylum. The closest cultured species were Paludibacter propionicigenes with 16S rRNA gene sequence similarity of 87.5% and several Dysgonomonas strains (similarities of 83.5-85.4 to the type strains). Based on the distinctive ecological, phenotypic and phylogenetic characteristics of strain ADRIT, a new genus and species Microbacter margulisiae gen. nov., sp. nov., is proposed. The type strain is ADRIT (=JCM 19374T =DSM 27471T).
    Steroids accumulate in the rearing water of commercial recirculating aquaculture systems
    Mota, V.C. ; Martins, C.I. ; Eding, E.H. ; Canário, A.V.M. ; Verreth, J.A.J. - \ 2014
    Aquacultural Engineering 62 (2014). - ISSN 0144-8609 - p. 9 - 16.
    rainbow-trout - noninvasive measurement - pleuronectes-platessa - treatment plants - atlantic salmon - free cortisol - waste-water - testosterone - fish - 17-alpha,20-beta-dihydroxy-4-pregnen-3-one
    Little information is available on steroid concentrations in the rearing water of aquaculture systems and whether they accumulate in recirculating aquaculture systems (RAS). Therefore this study aimed at determining (1) the concentrations and variation of cortisol and sex steroids in RAS, (2) the contribution of fish rearing conditions to steroid concentrations in seven commercial RAS. Each RAS was sampled twice at three different points: (1) make-up water; (2) influent and (3) effluent of the rearing unit. The results showed significant higher steroid concentrations in the influent and effluent when compared with the make-up water. On average cortisol concentration was 15.7% higher in the effluent when compared with the influent. Mean steroid concentrations in the rearing unit effluent varied between: 3.8–217.0 ng/L for cortisol, 3–12.5 ng/L for testosterone, 0.9–7.1 ng/L for 11-ketoteststerone and 1.8–12.8 ng/L for 17,20ß-dihydroxypregn-4-en-3-one. Stocking density, Total Ammonia-Nitrogen concentration and orthophosphate-P concentration (a measure of make-up water usage) showed a positive correlation with sex steroids in the water. The steroid concentrations from the present study were orders of magnitude lower than initial estimations indicating a water treatment efficiency of >99%. The results suggest that an intensification of fish production through decrease of make-up water use and increase of stocking density will lead to a build-up of steroids in the water. Although intensification is critical for the economical success of RAS, this ultimately could affect fish performance as steroids accumulates in the water of RAS at levels that can potentially be detected by some fish species.
    Effect of granular activated carbon concentration on the content of organic matter and salt, influencing E. coli activity and survival in fluidized bed disinfection reactor
    Racyte, J. ; Langenhoff, A.A.M. ; Ribeiro, A.F.M.M.R. ; Paulitsch-Fuchs, A.H. ; Bruning, H. ; Rijnaarts, H. - \ 2014
    Biotechnology and Bioengineering 111 (2014)10. - ISSN 0006-3592 - p. 2009 - 2018.
    alternating electric-fields - waste-water - bacteria - growth - bioluminescence - physiology - o157-h7 - stress - system - ph
    Granular activated carbon (GAC) is used in water treatment systems, typically to remove pollutants such as natural organic matter, volatile organic compounds, chlorine, taste, and odor. GAC is also used as a key component of a new technology that combines a fluidized bed reactor with radio frequency electric fields for disinfection. So far, the effects of GAC on bacteria in these fluidized bed reactors are unclear. This paper describes a systematic study of the physico-chemical changes in five microbial media compositions caused by different concentrations (23–350¿g/L) of GAC, and the effects of these physico-chemical changes on the metabolic activity and survival of a model microorganism (Escherichia coli YMc10) in a fluidized bed reactor. The chemical adsorption taking place in suspensions with specific GAC changed nutritional, osmotic, and pH conditions in the investigated microbial media (LB, diluted LB, PBS, diluted PBS, and tap water), leading to a decay of the metabolic activity and survival of E. coli. Especially media that are poor in organic and mineral compounds (e.g., PBS) with suspended GAC showed a concentration decay of 3.5¿Log CFU/mL E. coli after 6¿h. Organic compounds depletion and severe pH variation were enhanced in the presence of higher GAC concentrations. Biotechnol. Bioeng. 2014;111: 2009–2018.
    In Situ Spatially and Temporally Resolved Measurements of Salt Concentration between Charging Porous Electrodes for Desalination by Capacitive Deionization
    Suss, M.E. ; Biesheuvel, P.M. ; Baumann, T.E. ; Stadermann, M. ; Santiago, J.G. - \ 2014
    Environmental Science and Technology 48 (2014)3. - ISSN 0013-936X - p. 2008 - 2015.
    mesoporous carbon - constant-current - ion-transport - waste-water - membrane - efficiency - performance - electrolytes - optimization - porosity
    Capacitive deionization (CDI) is an emerging water desalination technique. In CDI, pairs of porous electrode capacitors are electrically charged to remove salt from brackish water present between the electrodes. We here present a novel experimental technique allowing measurement of spatially and temporally resolved salt concentration between the CDI electrodes. Our technique measures the local fluorescence intensity of a neutrally charged fluorescent probe which is collisionally quenched by chloride ions. To our knowledge, our system is the first to measure in situ and spatially resolved chloride concentration in a laboratory CDI cell. We here demonstrate good agreement between our dynamic measurements of salt concentration in a charging, millimeter-scale CDI system to the results of a modified Donnan porous electrode transport model. Further, we utilize our dynamic measurements to demonstrate that salt removal between our charging CDI electrodes occurs on a longer time scale than the capacitive charging time scales of our CDI cell. Compared to typical measurements of CDI system performance (namely, measurements of outflow ionic conductivity), our technique can enable more advanced and better-controlled studies of ion transport in CDI systems, which can potentially catalyze future performance improvements.
    Electrochemical conversion of micropollutants in gray water
    Butkovskyi, A. ; Jeremiasse, A.W. ; Hernandez Leal, L. ; Zande, T. van der; Rijnaarts, H. ; Zeeman, G. - \ 2014
    Environmental Science and Technology 48 (2014)3. - ISSN 0013-936X - p. 1893 - 1901.
    waste-water - bisphenol-a - anodic-oxidation - organic pollutants - treatment systems - by-products - degradation - electrodes - removal - disinfection
    Electrochemical conversion of micropollutants in real gray water effluent was studied for the first time. Six compounds that are frequently found in personal care and household products, namely methylparaben, propylparaben, bisphenol A, triclosan, galaxolide, and 4- methylbenzilidene camphor (4-MBC), were analyzed in the effluent of the aerobic gray water treatment system in full operation. The effluent was used for lab-scale experiments with an electrochemical cell operated in batch mode. Three different anodes and five different cathodes have been tested. Among the anodes, Ru/Ir mixed metal oxide showed the best performance. Ag and Pt cathodes worked slightly better than Ti and mixed metal oxide cathodes. The compounds that contain a phenolic ring (parabens, bisphenol A, and triclosan) were completely transformed on this anode at a specific electric charge Q = 0.03 Ah/L. The compounds, which contain a benzene ring and multiple side methyl methyl groups (galaxolide, 4-MBC) required high energy input (Q = 0.6 Ah/L) for transformation. Concentrations of adsorbable organohalogens (AOX) in the gray water effluent increased significantly upon treatment for all electrode combinations tested. Oxidation of gray water on mixed metal oxide anodes could not be recommended as a post-treatment step for gray water treatment according to the results of this study. Possible solutions to overcome disadvantages revealed within this study are proposed.
    Aryl hydrocarbon receptor (AhR) inducers and estrogen receptor (ER) activities in surface sediments of Three Gorges Reservoir, China evaluated with in vitro cell bioassays
    Wang, J. ; Bovee, T.F.H. ; Bi, Y. ; Bernhöft, S. ; Schramm, K.W. - \ 2014
    Environmental Science and Pollution Research 21 (2014)4. - ISSN 0944-1344 - p. 3145 - 3155.
    lumbriculus-variegatus oligochaeta - endocrine disrupting chemicals - green fluorescent protein - effect-directed analysis - yangtze-river - dioxin-like - environmental-samples - waste-water - steroidal estrogens - toxicity
    Two types of biological tests were employed for monitoring the toxicological profile of sediment cores in the Three Gorges Reservoir (TGR), China. In the present study, sediments collected in June 2010 from TGR were analyzed for estrogen receptor (ER)- and aryl hydrocarbon receptor (AhR)-mediated activities. The estrogenic activity was assessed using a rapid yeast estrogen bioassay, based on the expression of a green fluorescent reporter protein. Weak anti-estrogenic activity was detected in sediments from an area close to the dam of the reservoir, and weak estrogenic activities ranging from 0.3 to 1 ng 17ß-estradiol (E2) equivalents (EQ) g-1 dry weight sediment (dw) were detected in sediments from the Wanzhou to Guojiaba areas. In the upstream areas Wanzhou and Wushan, sediments demonstrated additive effects in co-administration of 1 nM E2 in the yeast test system, while sediments from the downstream Badong and Guojiaba areas showed estrogenic activities which seemed to be more than additive (synergistic activity). There was an increasing tendency in estrogenic activity from upstream of TGR to downstream, while this tendency terminated and converted into anti-estrogenic activity in the area close to the dam. The AhR activity was detected employing rat hepatoma cell line (H4IIE). EROD activities were found homogenously distributed in sediments in TGR ranging from 200 to 311 pg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) EQ g-1 dw for total AhR agonists and from 45 to 76 pg TCDD EQ g-1 dw for more persistent AhR agonists. The known AhR agonists polycyclic aromatic hydrocarbon, polychlorinated biphenyl, and PCDD/F only explained up to 8 % of the more persistent AhR agonist activity in the samples, which suggests that unidentified AhR-active compounds represented a great proportion of the TCDD EQ in sediments from TGR. These findings of estrogenic potential and dioxin-like activity in TGR sediments provide possible weight-of-evidence of potential ecotoxicological causes for the declines in fish populations which have been observed during the past decades in TGR.
    Calcium phosphate granulation in anaerobic treatment of black water: a new approach to phosphorus recovery
    Tervahauta, T.H. ; Weijden, R.D. van der; Flemming, R.L. ; Hernández, L. ; Zeeman, G. ; Buisman, C.J.N. - \ 2014
    Water Research 48 (2014)1. - ISSN 0043-1354 - p. 632 - 642.
    afvalwaterbehandeling - afvalhergebruik - slibzuivering - calciumfosfaten - fosfor - terugwinning - spectroscopie - infraroodspectroscopie - anaërobe behandeling - biobased economy - waste water treatment - waste utilization - sludge treatment - calcium phosphates - phosphorus - recovery - spectroscopy - infrared spectroscopy - anaerobic treatment - biobased economy - waste-water - precipitation - hydroxyapatite - struvite
    Recovery of phosphorus from wastewater as calcium phosphate could diminish the need for mining of scarce phosphate rock resources. This study introduces a novel approach to phosphorus recovery by precipitation of calcium phosphate granules in anaerobic treatment of black water. The granules formed in the Upflow Anaerobic Sludge Blanket (UASB) reactor at lab- and demonstration-scale were analyzed for chemical composition and mineralogy by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), Electron microprobe (EMP), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and micro X-ray Diffraction (XRD). The granules had a diameter of 1–2 mm, organic content of 33 wt%, and phosphorus content of 11–13 wt%. Three calcium phosphate phases were identified in the granules: hydroxyapatite, calcium phosphate hydrate and carbonated hydroxyapatite. Without any addition of chemicals, 7 gP/person/year can be recovered with the calcium phosphate granules, representing 2% of the incoming phosphorus in the UASB reactor. As the heavy metal content was lower compared to other phosphorus recovery products, phosphate rock and phosphorus fertilizer, the calcium phosphate granules could be considered as a new phosphorus product.
    Sulfate Reduction at Low Ph To Remediate Acid Mine Drainage
    Sánchez-Andrea, I. ; Sanz, J.L. ; Bijmans, M.F.M. ; Stams, A.J.M. - \ 2014
    Journal of Hazardous Materials 269 (2014). - ISSN 0304-3894 - p. 98 - 109.
    fluidized-bed reactor - metal-contaminated water - rate-determining step - reducing bacteria - waste-water - microbial community - sp-nov - biological treatment - constructed wetland - passive treatment
    Industrial activities and the natural oxidation of metallic sulfide-ores produce sulfate-rich waters with low pH and high heavy metals content, generally termed acid mine drainage (AMD). This is of great environmental concern as some heavy metals are highly toxic. Within a number of possibilities, biological treatment applying sulfate-reducing bacteria (SRB) is an attractive option to treat AMD and to recover metals. The process produces alkalinity, neutralizing the AMD. Simultaneously. The sulfide that is produced react with the metal in solution and precipitates them as metal sulfides. Here, important factors for biotechnological application of SRB such as the inocula, the pH of the process, the substrates and the reactor design are discussed. Microbial communities of sulfidogenic reactors treating AMD which comprise fermentative-, acetogenic- and SRB as well as methanogenic archaea are reviewed
    Tracing enteric viruses in the European berry fruit supply chain
    Maunula, L. ; Kaupke, A. ; Vasickova, P. ; Soderberg, K. ; Kozyra, I. ; Lazic, S. ; Poel, W.H.M. van der; Bouwknegt, M. ; Rutjes, S. ; Willems, K.A. ; Moloney, R. ; Agostino, M. D'; Husman, A.M.D. ; Bonsdorff, C.H. ; Rzezutka, A. ; Pavlik, I. ; Petrovic, T. ; Cook, N. - \ 2013
    International Journal of Food Microbiology 167 (2013)2. - ISSN 0168-1605 - p. 177 - 185.
    hepatitis-e virus - reverse transcription-pcr - time rt-pcr - waste-water - norovirus outbreaks - frozen raspberries - food safety - a virus - transmission - infection
    In recent years, numerous foodborne outbreaks due to consumption of berry fruit contaminated by human enteric viruses have been reported. This European multinational study investigated possible contamination routes by monitoring the entire food chain for a panel of human and animal enteric viruses. A total of 785 samples were collected throughout the food production chain of four European countries (Czech Republic, Finland, Poland and Serbia) during two growing seasons. Samples were taken during the production phase, the processing phase, and at point-of-sale. Samples included irrigation water, animal faeces, food handlers' hand swabs, swabs from toilets on farms, from conveyor belts at processing plants, and of raspberries or strawberries at points-of-sale; all were subjected to virus analysis. The samples were analysed by real-time (reverse transcription, RT)-PCR, primarily for human adenoviruses (hAdV) to demonstrate that a route of contamination existed from infected persons to the food supply chain. The analyses also included testing for the presence of selected human (norovirus, NoV GI, NoV GII and hepatitis A virus, HAV), animal (porcine adenovirus, pAdV and bovine polyomavirus, bPyV) and zoonotic (hepatitis E virus, HEV) viruses. At berry production, hAdV was found in 9.5%, 5.8% and 9.1% of samples of irrigation water, food handlers' hands and toilets, respectively. At the processing plants, hAdV was detected in one (2.0%) swab from a food handler's hand. At point-of-sale, the prevalence of hAdV in fresh raspberries, frozen raspberries and fresh strawberries, was 0.7%, 3.2% and 2.0%, respectively. Of the human pathogenic viruses, NoV GII was detected in two (3.6%) water samples at berry production, but no HAV was detected in any of the samples. HEV-contaminated frozen raspberries were found once (2.6%). Animal faecal contamination was evidenced by positive pAdV and bPyV assay results. At berry production, one water sample contained both viruses, and at point-of-sale 5.7% and 13% of fresh and frozen berries tested positive for pAdV. At berry production hAdV was found both in irrigation water and on food handler's hands, which indicated that these may be important vehicles by which human pathogenic viruses enter the berry fruit chain. Moreover, both zoonotic and animal enteric viruses could be detected on the end products. This study gives insight into viral sources and transmission routes and emphasizes the necessity for thorough compliance with good agricultural and hygienic practice at the farms to help protect the public from viral infections. (C) 2013 Elsevier B.V. All rights reserved.
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