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.

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Nitrous oxide (N2O) emissions from biotrickling filters used for ammonia removal at livestock facilities
Melse, R.W. ; Mosquera Losada, J. - \ 2014
Water Science and Technology 69 (2014)5. - ISSN 0273-1223 - p. 994 - 1003.
activated-sludge - liquid fraction - water-treatment - nitric-oxide - air - nitrification - operations - manure
Recently several manufacturers of nitrifying biotrickling filters for ammonia (NH3) removal at animal houses have started to add a denitrification step to the installation, aiming to reduce the amount of discharge water by conversion of NH3 to nitrogen gas (N2). The aim of this research was to quantify the possible formation of nitrous oxide (N2O), which is a potent greenhouse gas, in three of these farm-scale installations. Furthermore, the removal efficiency of NH3 and odor was determined. All installations were successful in reducing the amount of discharge water. The average NH3 removal efficiency for the three locations was 85, 71 and 86%, respectively. However, a significant part of the NH3 removed from the inlet air was not converted to N2 but to N2O, which is a potent greenhouse gas. The part of the inlet NH3-N that was converted to N2O-N amounted to 17, 66 and 24%, respectively. The high N2O production might have been caused by a too low scarcity of biodegradable carbon/N ratio for complete denitrification. The average odor removal efficiency was 21, 32 and 48%, respectively. Further research is necessary to explore how process conditions can be adjusted and controlled in order to reduce the production and emission of N2O from these types of systems.
Comparing the environmental impact of a nitrifiying biotrickling filter with or without denitrification for ammonia abatement at animal houses
Vries, J.W. de; Melse, R.W. - \ 2014
Lelystad : Wageningen UR Livestock Research (Report / Wageningen UR Livestock Research 717) - 14
intensieve veehouderij - varkenshouderij - rundveehouderij - luchtreinigers - nitrificatie - denitrificatie - vergelijkend onderzoek - filters - ammoniakemissie - fijn stof - broeikasgassen - intensive livestock farming - pig farming - cattle husbandry - air cleaners - nitrification - denitrification - comparative research - ammonia emission - particulate matter - greenhouse gases
The aim was to assess the environmental impact of a biotrickling filter with nitrification only and with subsequent denitrification. Life cycle assessment was applied to assess greenhouse gases, nitrate, ammonia and fossil fuel depletion. The biotrickling filter with nitrification and denitrification had higher greenhouse gas emission, whereas nitrification only had higher nitrate leaching and ammonia emission from field application of discharge water
Balancing the organic load and light supply in symbiotic microalgal–bacterial biofilm reactors treating synthetic municipal wastewater
Boelee, N.C. ; Temmink, B.G. ; Janssen, M. ; Buisman, C.J.N. ; Wijffels, R.H. - \ 2014
Ecological Engineering 64 (2014). - ISSN 0925-8574 - p. 213 - 221.
afvalwaterbehandeling - biofilms - symbiose - algen - bacteriën - heterotrofe micro-organismen - fotosynthese - acetaten - stikstof - fosfor - nitrificatie - denitrificatie - biologische waterzuiveringsinstallaties - biobased economy - waste water treatment - symbiosis - algae - bacteria - heterotrophic microorganisms - photosynthesis - acetates - nitrogen - phosphorus - nitrification - denitrification - biological water treatment plants - activated-sludge - nutrient removal - growth - phytoplankton - fluorescence - enhancement
Symbiotic microalgal–bacterial biofilms can be very attractive for municipal wastewater treatment. Microalgae remove nitrogen and phosphorus and simultaneously produce the oxygen that is required for the aerobic, heterotrophic degradation of organic pollutants. For the application of these biofilms in new wastewater treatment systems, the engineering aspects need to be investigated to obtain a balanced system where no additional oxygen is required. In this study symbiotic microalgal–bacterial biofilms were grown in flow cells with ammonium and phosphate, and with acetate as biodegradable organic pollutant at a hydraulic retention time of 4.5 h. The symbiotic biofilms removed acetate from 323 mg/L to 39 mg/L without an external oxygen or carbon dioxide supply at a removal rate of 43 g COD/m2/d. Ammonium and phosphate could not be completely removed, but removal rates of 3.2 g/m2/d and 0.41 g/m2/d were obtained, respectively. Further nitrogen removal may be obtained by nitrification and denitrification as the biofilm obtained a considerable heterotrophic denitrification capacity. The symbiotic relationship between microalgae and aerobic heterotrophs was proven by subsequently removing light and acetate. In both cases this resulted in the cessation of the symbiosis and in increasing effluent concentrations of both acetate and the nutrients ammonium and phosphate. Future research should investigate the dimensioning of an up-scaled symbiotic biofilm reactor, and the possibilities to obtain additional nitrogen and phosphorus removal under day–night cycles utilizing real wastewater.
Interactions between microbial-feeding and predatory soil fauna trigger N2O emissions
Thakur, M.P. ; Groenigen, J.W. van; Kuiper, I. ; Deyn, G.B. de - \ 2014
Soil Biology and Biochemistry 70 (2014). - ISSN 0038-0717 - p. 256 - 262.
nitrogen mineralization - enchytraeid worms - trophic cascades - food webs - raw humus - decomposition - biodiversity - nitrification - oligochaeta - microarthropods
Recent research has shown that microbial-feeding invertebrate soil fauna species can significantly contribute to N2O emissions. However, in soil food webs microbial-feeding soil fauna interact with each other and with their predators, which affects microbial activity. To date we lack empirical tests of whether or not these interactions play a significant role in N2O emissions from soil. Therefore we studied how interactions between soil microbes, two groups of microbial-feeding soil fauna (enchytraeids and fungivorous mites) and their predators (predatory mites) affect soil N2O emissions. We hypothesized that: 1) the presence of two microbial-feeding fauna groups (enchytraeids and fungivorous mites) together increase N2O emissions more than when only a single group is present; and 2) the addition of predatory mites further enhances N2O emissions. We assembled soil food webs consisting of soil microbes, enchytraeids, fungivorous and predatory mites in microcosms with sandy loamy soil and sterilised hay as a substrate for the soil microbes. N2O emissions were measured during 56 days. We found no support for our first yet support for our second hypothesis. Addition of predatory mites to microcosms with enchytraeids and fungivorous mites increased N2O emissions significantly from 135.3 to 482.1 mg N m-2, which was also significantly higher than the control without fauna (83 mg N m-2) (P <0.001). In presence of enchytraeids, fungivorous and predatory mites, we found much higher nitrate availability at the time of the N2O peak on Day 35 (10.9 versus 5.5 mg N per kg soil without soil fauna), indicating that the major increase in N2O emissions in this treatment may be due to increased nitrification. Increased nitrification may be attributed to higher availability of N from the dead tissues of fungivorous mites and increased activity of the enchytraeids that might also have affected soil structure and contributed to increased N2O emissions. This study demonstrates the importance of interactions between microbial-feeding invertebrate soil fauna and their predators in understanding N2O emissions.
Different land use intensities in grassland ecosystems drive ecology of microbial communities involved in nitrogen turnover in soil
Meyer, A. ; Focks, A. ; Radl, V. ; Keil, D. ; Welzl, G. ; Schoning, I. ; Boch, S. - \ 2013
PLoS One 8 (2013)9. - ISSN 1932-6203
ammonia-oxidizing archaea - denitrifying bacteria - management-practices - species composition - nosz genes - nitrification - abundance - nirk - diversity - denitrification
Understanding factors driving the ecology of N cycling microbial communities is of central importance for sustainable land use. In this study we report changes of abundance of denitrifiers, nitrifiers and nitrogen-fixing microorganisms (based on qPCR data for selected functional genes) in response to different land use intensity levels and the consequences for potential turnover rates. We investigated selected grassland sites being comparable with respect to soil type and climatic conditions, which have been continuously treated for many years as intensely used meadows (IM), intensely used mown pastures (IP) and extensively used pastures (EP), respectively. The obtained data were linked to above ground biodiversity pattern as well as water extractable fractions of nitrogen and carbon in soil. Shifts in land use intensity changed plant community composition from systems dominated by s-strategists in extensive managed grasslands to c-strategist dominated communities in intensive managed grasslands. Along the different types of land use intensity, the availability of inorganic nitrogen regulated the abundance of bacterial and archaeal ammonia oxidizers. In contrast, the amount of dissolved organic nitrogen determined the abundance of denitrifiers (nirS and nirK). The high abundance of nifH carrying bacteria at intensive managed sites gave evidence that the amounts of substrates as energy source outcompete the high availability of inorganic nitrogen in these sites. Overall, we revealed that abundance and function of microorganisms involved in key processes of inorganic N cycling (nitrification, denitrification and N fixation) might be independently regulated by different abiotic and biotic factors in response to land use intensity.
Apparatus for the ammonium recovery from liquid animal manure
Starmans, D.A.J. ; Timmerman, M. - \ 2013
Applied Engineering in Agriculture 29 (2013)5. - ISSN 0883-8542 - p. 761 - 767.
denitrification - nitrification - removal
Nitrogen present in animal manure can be a limiting factor when considering manure application rates onto arable land. EU-regulations triggered the development of a new ammonia exchange apparatus for the recovery of ammonia. The described apparatus has a liquid to liquid ammonia mass transfer coefficient of 0.0058 m/s. The results were fitted using a simple first order ammonia exchange model with constant time step that additionally predicted that 80% of the ammonia could be recycled from the liquid fraction of animal manure within a residence time of 10 h with addition of 0.2 M NaOH to the manure, yielding a liquid artificial fertilizer with a calculated achievable maximum concentration of about 18 % nitrogen.
Potato cultivar type affects the structure of ammonia oxidizer communities in field soil under potato beyond the rhizosphere
Dias, A.C.F. ; Hoogwout, E.F. ; Silva, M.D.P.E. ; Salles, J.F. ; Overbeek, L.S. van; Elsas, J.D. - \ 2012
Soil Biology and Biochemistry 50 (2012). - ISSN 0038-0717 - p. 85 - 95.
gradient gel-electrophoresis - 16s ribosomal-rna - important players - acid soil - archaea - bacteria - abundance - nitrification - oxidation - crenarchaeota
The effects of plants on the microbiota involved in the oxidation of ammonia in soils have been controversial. Here, we investigated the dynamics in the abundances and community structures of the bacterial and archaeal ammonia oxidizers (AOB and AOA, respectively) in two fields that were cropped with potato. Six different potato cultivars were used, including a genetically-modified one, in a fourfold replicated experimental set-up. On the basis of bulk and rhizosphere soil extracted microbial community DNA, AOB and AOA quantitative PCR as well as PCR-DGGE were performed. In addition, samples were used for the production and analysis of amoA gene fragment based clone libraries. Regardless of sample type (bulk versus rhizosphere soil) and across soils, the population sizes of AOA (of the order 10(4)-10(8) amoA gene copies g(-1) dry soil), were generally higher than those of AOB in the same samples (about 10(4)-10(5) g(-1) dry soil), resulting in ratio's of log-transformed values > 1.0. Whereas the AOB numbers were generally raised in the rhizosphere versus bulk soils in both soils, the opposite was true for the AOA numbers. Moreover, significant effects of cultivar type on both the AOB and AOA community structures were found in both soils, and these extended to beyond the rhizospheres. The effects were found across the whole growth season. Soil type did not significantly affect the community structures of AOA, but had a small effect on the community structure of AOB. Analysis of the structures of the AOB communities revealed a prevalence of AOB subgroups 2, 3a, 3b and 4 in one field soil and of 2 and 4 in the other one. With respect to the AOA, soil/sediment clusters (SS) I, II, III and IV were found to prevail.
Biotrickling filter for the treatment of exhaust air from a pig rearing building: Ammonia removal performance and its fluctuations
Melse, R.W. ; Ploegaert, J.P.M. ; Ogink, N.W.M. - \ 2012
Biosystems Engineering 113 (2012)3. - ISSN 1537-5110 - p. 242 - 252.
nitrous-acid - inhibition - nitrification - operations - gases - odor - nh3
The removal of ammonia (NH3) by a full scale packed-bed biotrickling filter (packing volume: 3.8 m3; water buffer tank: 20 m3) under fluctuating loading conditions was studied. The unit was operated at an animal house for treatment of exhaust air at an average air contact time of 1.2 s. Continuous long-term ammonia measurements showed average inlet and outlet air concentrations of 14 ppm and 2.4 ppm, respectively, and a removal efficiency of 82%. The average temperature of the water was 16 °C, the pH 6.6, the ammonium concentration 1.9 g N l-1, and the nitrate concentration 1.8 g N l-1; no nitrite was detected. The average ammonia loading and removal rate were 29 and 24 g NH3 m-3 h-1, respectively. A daily and seasonal pattern could be observed in the ammonia removal performance. With increasing outside temperature ammonia loading rate, ammonia removal rate, and ammonia outlet concentration increased, resulting in a net decrease of the ammonia removal efficiency. This phenomenon might be explained by the existence of equilibrium between the ammonia concentration in the outlet air and the concentration of dissolved ammonia in the water, which is influenced by fluctuating air and water temperature. A nitrogen balance indicated that 86% of the removed ammonia-N was discharged or accumulated in the water as ammonium and nitrate, and 5% was emitted as nitrous oxide (N2O). The fluctuating removal patterns that were found suggest that current regulatory performance monitoring practices need to be improved
Predicting microbial nitrogen pathways from basic principles
Leemput, I.A. van de; Veraart, A.J. ; Dakos, V. ; Klein, J.J.M. de; Strous, M. ; Scheffer, M. - \ 2011
Environmental Microbiology 13 (2011)6. - ISSN 1462-2912 - p. 1477 - 1487.
anaerobic ammonium oxidation - dissimilatory nitrate reduction - fresh-water sediment - estuarine sediment - growth yields - waste-water - denitrification - bacteria - nitrification - anammox
Nitrogen compounds are transformed by a complicated network of competing geochemical processes or microbial pathways, each performed by a different ecological guild of microorganisms. Complete experimental unravelling of this network requires a prohibitive experimental effort. Here we present a simple model that predicts relative rates of hypothetical nitrogen pathways, based only on the stoichiometry and energy yield of the performed redox reaction, assuming competition for resources between alternative pathways. Simulating competing pathways in hypothetical freshwater and marine sediment situations, we surprisingly found that much of the variation observed in nature can simply be predicted from these basic principles. Investigating discrepancies between observations and predictions led to two important biochemical factors that may create barriers for the viability of pathways: enzymatic costs for long pathways and high ammonium activation energy. We hypothesize that some discrepancies can be explained by non-equilibrium dynamics. The model predicted a pathway that has not been discovered in nature yet: the dismutation of nitrite to the level of nitrate and dinitrogen gas
Effects of aquatic vegetation type on denitrification
Veraart, A.J. ; Bruijne, W.J.J. de; Peeters, E.T.H.M. ; Klein, J.J.M. de; Scheffer, M. - \ 2011
Biogeochemistry 104 (2011)1-3. - ISSN 0168-2563 - p. 267 - 274.
sloten - waterplanten - zoetwaterecologie - stikstof - aquatische ecologie - nitrificatie - ditches - aquatic plants - freshwater ecology - nitrogen - aquatic ecology - nitrification - fresh-water - submersed macrophytes - drainage ditches - nitrate removal - lemna-minor - sediment - plant - eutrophication - ecosystems
In a microcosm 15N enrichment experiment we tested the effect of floating vegetation (Lemna sp.) and submerged vegetation (Elodea nuttallii) on denitrification rates, and compared it to systems without macrophytes. Oxygen concentration, and thus photosynthesis, plays an important role in regulating denitrification rates and therefore the experiments were performed under dark as well as under light conditions. Denitrification rates differed widely between treatments, ranging from 2.8 to 20.9 µmol N m-2 h-1, and were strongly affected by the type of macrophytes present. These differences may be explained by the effects of macrophytes on oxygen conditions. Highest denitrification rates were observed under a closed mat of floating macrophytes where oxygen concentrations were low. In the light, denitrification was inhibited by oxygen from photosynthesis by submerged macrophytes, and by benthic algae in the systems without macrophytes. However, in microcosms with floating vegetation there was no effect of light, as the closed mat of floating plants caused permanently dark conditions in the water column. Nitrate removal was dominated by plant uptake rather than denitrification, and did not differ between systems with submerged or floating plants
Warming can boost denitrification disproportionately due to altered oxygen dynamics
Veraart, A.J. ; Klein, J.J.M. de; Scheffer, M. - \ 2011
PLoS One 6 (2011)3. - ISSN 1932-6203 - 6 p.
nitrous-oxide - estuarine sediments - gaseous nitrogen - fresh-water - temperature - nitrate - nitrification - ecosystems - soils - model
Background - Global warming and the alteration of the global nitrogen cycle are major anthropogenic threats to the environment. Denitrification, the biological conversion of nitrate to gaseous nitrogen, removes a substantial fraction of the nitrogen from aquatic ecosystems, and can therefore help to reduce eutrophication effects. However, potential responses of denitrification to warming are poorly understood. Although several studies have reported increased denitrification rates with rising temperature, the impact of temperature on denitrification seems to vary widely between systems. Methodology/Principal Findings - We explored the effects of warming on denitrification rates using microcosm experiments, field measurements and a simple model approach. Our results suggest that a three degree temperature rise will double denitrification rates. By performing experiments at fixed oxygen concentrations as well as with oxygen concentrations varying freely with temperature, we demonstrate that this strong temperature dependence of denitrification can be explained by a systematic decrease of oxygen concentrations with rising temperature. Warming decreases oxygen concentrations due to reduced solubility, and more importantly, because respiration rates rise more steeply with temperature than photosynthesis. Conclusions/Significance - Our results show that denitrification rates in aquatic ecosystems are strongly temperature dependent, and that this is amplified by the temperature dependencies of photosynthesis and respiration. Our results illustrate the broader phenomenon that coupling of temperature dependent reactions may in some situations strongly alter overall effects of temperature on ecological processes
Source Determination of Nitrous Oxide Based on Nitrogen and Oxygen Isotope Tracing: Dealing with Oxygen exchange
Kool, D.M. ; Groenigen, J.W. van; Wrage, N. - \ 2011
In: Methods in Enzymology : Research on Nitrification and Related Processes, Part B Volume 496 / Klotz, M.G., Stein, L.Y., Burlington : Elsevier - ISBN 9780123864895 - p. 139 - 160.
dissimilatory nitrate reduction - ammonia-oxidizing bacteria - nitrifier denitrification - nitrosomonas-europaea - labeling method - stable-isotope - soil - n2o - nitrification - water
Source determination of nitrous oxide (N2O) from soils has so far been complicated by methodological constraints: the frequently used 15N tracer method could not differentiate between pathways related to nitrification, that is, nitrifier nitrification (NN), nitrifier denitrification (ND), and nitrification-coupled denitrification (NCD). To overcome this problem, a dual isotope method using both 15N and 18O was proposed. However, O exchange between nitrogen oxides and water has been found to disturb such a method. We here explain in detail a novel dual isotope method that allows to quantify O exchange in denitrification and to differentiate N2O production from NN, ND, NCD, and fertilizer denitrification (FD). The method has already been applied to a range of soils with good success. Potential of and scope for further improvement of the method are discussed
Treatment of domestic wastewater in an up-flow anaerobic sludge blanket reactor followed by moving bed biofilm reactor
Tawfik, A. ; El-Gohary, F. ; Temmink, B.G. - \ 2010
Bioprocess and Biosystems Engineering 33 (2010)2. - ISSN 1615-7591 - p. 267 - 276.
sponge dhs system - nitrogen removal - low-temperatures - uasb reactors - sewage - denitrification - nitrification - retention - effluent - time
The performance of a laboratory-scale sewage treatment system composed of an up-flow anaerobic sludge blanket (UASB) reactor and a moving bed biofilm reactor (MBBR) at a temperature of (22-35 A degrees C) was evaluated. The entire treatment system was operated at different hydraulic retention times (HRT's) of 13.3, 10 and 5.0 h. An overall reduction of 80-86% for CODtotal; 51-73% for CODcolloidal and 20-55% for CODsoluble was found at a total HRT of 5-10 h, respectively. By prolonging the HRT to 13.3 h, the removal efficiencies of CODtotal, CODcolloidal and CODsoluble increased up to 92, 89 and 80%, respectively. However, the removal efficiency of CODsuspended in the combined system remained unaffected when increasing the total HRT from 5 to 10 h and from 10 to 13.3 h. This indicates that, the removal of CODsuspended was independent on the imposed HRT. Ammonia-nitrogen removal in MBBR treating UASB reactor effluent was significantly influenced by organic loading rate (OLR). 62% of ammonia was eliminated at OLR of 4.6 g COD m(-2) day(-1). The removal efficiency was decreased by a value of 34 and 43% at a higher OLR's of 7.4 and 17.8 g COD m(-2) day(-1), respectively. The mean overall residual counts of faecal coliform in the final effluent were 8.9 x 10(4) MPN per 100 ml at a HRT of 13.3 h, 4.9 x 10(5) MPN per 100 ml at a HRT of 10 h and 9.4 x 10(5) MPN per 100 ml at a HRT of 5.0 h, corresponding to overall log(10) reduction of 2.3, 1.4 and 0.7, respectively. The discharged sludge from UASB-MBBR exerts an excellent settling property. Moreover, the mean value of the net sludge yield was only 6% in UASB reactor and 7% in the MBBR of the total influent COD at a total HRT of 13.3 h. Accordingly, the use of the combined UASB-MBBR system for sewage treatment is recommended at a total HRT of 13.3 h.
Long term partial nitritation of anaerobically treated black water and the emission of nitrous oxide
Graaff, M.S. de; Zeeman, G. ; Temmink, B.G. ; Loosdrecht, M.C.M. ; Buisman, C.J.N. - \ 2010
Water Research 44 (2010)7. - ISSN 0043-1354 - p. 2171 - 2178.
rioolafvalwater - rioolwater - excreten - huishoudens - afvoerwater - nieuwe sanitatie - afvalwaterbehandeling - nitrificatie - ammonium - anaërobe behandeling - sewage effluent - sewage - excreta - households - effluents - new sanitation - waste water treatment - nitrification - anaerobic treatment - anammox reactor - waste-water - start-up - removal - ammonia - sharon - supernatant - management - digestion
Black water (toilet water) contains half the load of organic material and the major fraction of the nutrients nitrogen and phosphorus in a household and is 25 times more concentrated, when collected with a vacuum toilet, than the total wastewater stream from a Dutch household. This research focuses on the partial nitritation of anaerobically treated black water to produce an effluent suitable to feed to the anammox process. Successful partial nitritation was achieved at 34 °C and 25 °C and for a long period (almost 400 days in the second period at 25 °C) without strict process control a stable effluent at a ratio of 1.3 NO2-N/NH4-N was produced which is suitable to feed to the anammox process. Nitrite oxidizers were successfully outcompeted due to inhibition by free ammonia and nitrous acid and due to fluctuating conditions in SRT (1.0–17 days) and pH (from 6.3 to 7.7) in the reactor. Microbial analysis of the sludge confirmed the presence of mainly ammonium oxidizers. The emission of nitrous oxide (N2O) is of growing concern and it corresponded to 0.6–2.6% (average 1.9%) of the total nitrogen load
Resource recovery from black water
Graaff, M.S. de - \ 2010
University. Promotor(en): Cees Buisman, co-promotor(en): Grietje Zeeman; Hardy Temmink. - [S.l. : S.n. - ISBN 9789085855484 - 192
rioolafvalwater - nieuwe sanitatie - anaërobe afbraak - bio-energie - nitrificatie - verzamelen - riolering - urine - sewage effluent - new sanitation - anaerobic digestion - bioenergy - nitrification - collection - sewerage
New sanitation systems based on separation at source offer a large potential for resource recovery from wastewater, e.g. energy and nutrients from black water and irrigation water from grey water. This review focuses on the components in source separated black water. The treatment options for the key components are reviewed, focusing on recovery of organic compounds, nitrogen and phosphorus and removal of hormones, pharmaceutical residues and pathogens. A feasible treatment system for black water (faeces and urine), collected with vacuum toilets, would consist of anaerobic treatment followed by struvite precipitation for phosphorus recovery and autotrophic nitrogen removal. By applying these techniques, it is possible to produce 56 MJ/p/y of electricity, representing 40% of the energy that now is required for conventional WWTPs. Furthermore, the production of global artificial phosphorus fertilizer can be reduced by maximum 21%. As an alternative a higher degree of separation could be applied by separating the urine from the faeces, but this only would be feasible if the urine can be directly reused as a fertilizer. The issue of hormones, pharmaceuticals and pathogens in wastewater and their entry into the environment requires more research to determine to which extent additional treatment is necessary. Finally, the scope of this thesis is explained and the research questions which were addressed are presented.
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
NH3 dynamics in composting : assessment of the integration of composting in manure management chains
Szanto, G.L. - \ 2009
University. Promotor(en): Wim Rulkens, co-promotor(en): A.H.M. Veeken. - [S.l. : S.n. - ISBN 9789085853695 - 140
dierlijke meststoffen - compostering - ammoniak - vervluchtiging - nitrificatie - mestverwerking - ammoniakemissie - animal manures - composting - ammonia - volatilization - nitrification - manure treatment - ammonia emission
The Dutch animal production sector copes with a manure problem. Their high nitrogen content makes manures popular fertilizers, but most of this nitrogen is emitted before it could be used by plants. Ammonia is the main emission form during the manure management chain of storage, transportation and land application. Composting these manures could improve their general storage and transport features, and produce stable composts. Still, the nitrogen retaining efficiency of composting is a matter of debate. This aspect of high- and low-tech composting treatments was examined through a technological research. The low-tech applications appeared to retain the nitrogen from ammonia by facilitating a complete nitrogen conversion process. High-tech processes do lose most of the ammonia, but this ammonia can be trapped to manufacture a separate fertilizer product. Although composting treatments are not free of emissions, their abilities to control the form and extent of harmful nitrogen emissions makes them potential choices in manure management.
The 18O signature of biogenic nitrous oxide is determined by O exchange with water
Kool, D.M. ; Wrage, N. ; Oenema, O. ; Harris, D. ; Groenigen, J.W. van - \ 2009
Rapid Communications in Mass Spectrometry 23 (2009)1. - ISSN 0951-4198 - p. 104 - 108.
oxygen-isotope ratios - seasonal-variation - arabian sea - n2o - denitrification - soil - nitrification - constraints - o-18/o-16 - catalysis
To effectively mitigate emissions of the greenhouse gas nitrous oxide (N2O) it is essential to understand the biochemical pathways by which it is produced. The 18O signature of N2O is increasingly used to characterize these processes. However, assumptions on the origin of the O atom and resultant isotopic composition of N2O that are based on reaction stoichiometry may be questioned. In particular, our deficient knowledge on O exchange between H2O and nitrogen oxides during N2O production complicates the interpretation of the 18O signature of N2O. Here we studied O exchange during N2O formation in soil, using a novel combination of 18O and 15N tracing. Twelve soils were studied, covering soil and land-use variability across Europe. All soils demonstrated the significant presence of O exchange, as incorporation of O from 18O-enriched H2O into N2O exceeded their maxima achievable through reaction stoichiometry. Based on the retention of the enrichment ratio of 18O and 15N of NO into N2O, we quantified O exchange during denitrification. Up to 97% (median 85%) of the N2O-O originated from H2O instead of from the denitrification substrate NO. We conclude that in soil, the main source of atmospheric N2O, the 18O signature of N2O is mainly determined by H2O due to O exchange between nitrogen oxides and H2O. This also challenges the assumption that the O of N2O originates from O2 and NO, in ratios reflecting reaction stoichiometry
Indicator voor stikstofmineralisatie in gescheurd grasland; synthese
Velthof, G.L. ; Schooten, H.A. van; Hoving, I.E. ; Dekker, P.H.M. ; Dam, A.M. van; Reijneveld, A. ; Aarts, H.F.M. ; Smit, A. - \ 2008
Wageningen : Alterra (Alterra-rapport 1768) - 41
graslanden - nitrificatie - bodemchemie - bodembiologie - nitraten - bouwland - grasslands - nitrification - soil chemistry - soil biology - nitrates - arable land
Op verzoek van LNV zijn in 2005, 2006 en 2007 verschillende laboratorium- en veldstudies uitgevoerd (proeven met aardappel, tulp en snijmais op zandgrond en kleigrond) met als doel het verkrijgen van een bodemanalyse-methode om de stikstofmineralisatie uit gescheurd grasland te voorspellen. Met deze methode kunnen laboratoria adviezen geven over de bemesting van het gewas dat na het vernietigen van grasland wordt geteeld. Dit bemestingsadvies is dan gebaseerd op de analyses van het gehalte aan minerale N en een voorspelling van de N-mineralisatie
A standardized method for the determination of the intrinsic carbon and nitrogen mineralization capacity of natural organic matter sources
Grigatti, M. ; Perez, M.D. ; Blok, W.J. ; Ciavatta, C. ; Veeken, A. - \ 2007
Soil Biology and Biochemistry 39 (2007)7. - ISSN 0038-0717 - p. 1493 - 1503.
compost stability - activated-sludge - crop residues - soil - nitrification - oxide - model - waste - denitrification - emission
A new method was developed for the simultaneous determination of the intrinsic carbon and nitrogen mineralization capacity of organic matter (OM) sources by means of an aerobic incubation in suspension. The proposed method is based on determination of the oxygen consumption, monitored indirectly via pressure measurement, and on determination of nitrogen mineralization, through the periodical measurement of NH4+-N, in a liquid suspension of the samples. The suspension is standardized in terms of nutrient composition and pH, and well-controlled incubation conditions that can be enforced as desired. This method rules out the effect of soil conditions and thus reflects the intrinsic properties of the OM. The method is faster and more reproducible than soil incubation tests that are currently used. In such a system, it is important that nitrification is inhibited to avoid oxygen consumption by nitrifiers and prevent the production of gaseous nitrogen compounds. Two nitrification inhibitors, N-allylthiourea and 2-ethynylpyridine, were tested at different concentrations for three reference samples, soil, bark and manure. Both inhibitors completely suppress NO3¿ formation without suppressing the heterotrophic microbial activity, thus allowing the correct determination of the oxygen uptake rate (OUR). When nitrification inhibitors were added, nitrous oxide could not be detected anymore in the gas phase of the system, which confirms that nitrification was inhibited and indicates that denitrification and nitrifier denitrification activity was negligible. N mineralization rates were determined by frequent sampling from the liquid phase of the system without disturbing the pressure measurement during the incubation and subsequent determination of NH4+-N. The method presented allows for the reliable and relatively easy and cheap, simultaneous determination of carbon and nitrogen mineralization rates for a wide range of OM sources.
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