Factors impacting biotransformation kinetics of trace organic compounds in lab-scale activated sludge systems performing nitrification and denitrification

Su, Lijuan; Aga, Diana S.; Chandran, Kartik; Khunjar, Wendell

doi:10.1016/j.jhazmat.2014.08.007

Cited by 49 publications

(18 citation statements)

References 44 publications

(32 reference statements)

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“…Similar kinetic effects of higher substrate concentration have also been observed in degradation studies of ibuprofen (Collado et al., 2012). More recent studies of TMP degradation have found that rate constants are not impacted as long as the TMP to COD ratio remains below 2 × 10 −3 (Su et al., 2015). This level lies approximately between the two extreme cases tested in this study (around 1 × 10 −4 and 2 × 10 −2 ).…”

Section: Resultsmentioning

confidence: 99%

“…To compare this with the observed removal in the pilot reactor, a modelling approach was used. Since studies of the anoxic removal of TMP have found that it has rate constants comparable to, or lower than those under aerobic conditions (Su et al., 2015, Burke et al., 2014), two modelling scenarios were applied: one with similar removal under aerobic and anoxic conditions and one with negligible removal under anoxic conditions. Biological degradation in the SBR was modelled at a fixed influent concentration by iterating Eq.…”

Section: Resultsmentioning

confidence: 99%

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New insights into the transformation of trimethoprim during biological wastewater treatment

et al. 2016

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The antibiotic trimethoprim (TMP), a micropollutant found at μg/L levels in raw wastewater, was investigated with regard to its (bio)transformation during biological wastewater treatment. A pilot-scale, nitrifying/denitrifying Sequencing Batch Reactor (SBR) fed with municipal wastewater was monitored for TMP removal during a 16-month monitoring study. Laboratory-scaled bioreactors spiked with TMP were applied to identify the transformation products (TPs). In total, six TPs could be identified from TMP. However, the TP formation was influenced by the spike concentration. At an initial concentration of 500 μg/L TMP, only two TPs were found, whereas at 5 μg/L a completely different transformation pathway led to four further TPs. At low concentrations, TMP was demethylated forming 4-desmethyl-TMP, which was then quickly hydroxylated, oxidized and cleaved forming 2,4-diaminopyrimidine-5-carboxylic acid (DAPC) via two intermediate TPs. DAPC was detected in the SBR effluent in a 3-d composite sample with 61 ng/L, which accounts for 52% of the attenuated TMP. The primary degradation at low spiking levels was best modelled by a pseudo-first order kinetic. Considering the SBR, the model predicted a TMP removal of 88–94% for the reactor, consistent with a monitoring campaign exhibiting an average removal of >83%. Both the TP formation profiles and kinetic modelling indicated that only the results from the bioreactor tests at low spike concentrations were representative of the transformation in the SBR.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

New insights into the transformation of trimethoprim during biological wastewater treatment

et al. 2016

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“…where C LI,in and C CJ,in denote the influent concentration of parent and retransformable fractions, respectively. 143 (triangles) and Su et al 211 (circles). Reported values refer to rate constants for biotransformation (biot, k Bio ), cometabolic biotransformation in the presence of growth substrate (biot-c, q Bio ) 33 The full-scale ASM-X implementation in WEST 2012 (DHI, Denmark), with parameters (k Bio , k Dec , K d , n LI,CJ ) estimated from batch experimental results and evaluated with measurements performed in a 3-day sampling campaign in Bekkelaget WWTP (Oslo, Norway), was used to estimate the elimination of the selected antibiotics.…”

Section: ■ Materials and Methodsmentioning

confidence: 96%

Removal of Antibiotics in Biological Wastewater Treatment Systems—A Critical Assessment Using the Activated Sludge Modeling Framework for Xenobiotics (ASM-X)

Polesel

Andersen

Trapp

et al. 2016

Environ. Sci. Technol.

140

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Many scientific studies present removal efficiencies for pharmaceuticals in laboratory-, pilot-, and full-scale wastewater treatment plants, based on observations that may be impacted by theoretical and methodological approaches used. In this Critical Review, we evaluated factors influencing observed removal efficiencies of three antibiotics (sulfamethoxazole, ciprofloxacin, tetracycline) in pilot- and full-scale biological treatment systems. Factors assessed include (i) retransformation to parent pharmaceuticals from e.g., conjugated metabolites and analogues, (ii) solid retention time (SRT), (iii) fractions sorbed onto solids, and (iv) dynamics in influent and effluent loading. A recently developed methodology was used, relying on the comparison of removal efficiency predictions (obtained with the Activated Sludge Model for Xenobiotics (ASM-X)) with representative measured data from literature. By applying this methodology, we demonstrated that (a) the elimination of sulfamethoxazole may be significantly underestimated when not considering retransformation from conjugated metabolites, depending on the type (urban or hospital) and size of upstream catchments; (b) operation at extended SRT may enhance antibiotic removal, as shown for sulfamethoxazole; (c) not accounting for fractions sorbed in influent and effluent solids may cause slight underestimation of ciprofloxacin removal efficiency. Using tetracycline as example substance, we ultimately evaluated implications of effluent dynamics and retransformation on environmental exposure and risk prediction.

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“…In particular, nitrogen can be transformed and removed by biologically mediated nitrification (aerobic process) and denitrification (anoxic process). Nitrification is a process which converts ammonia to nitrites and then to nitrates, while denitrification results in the transformation of nitrates and nitrites into nitrogen gas [38]. Figure 5 shows the results of the batches of denitrification processes on mixed liquor (batches DM1 and DM2) by following N-NO 3 , and the SCOD concentration over time.…”

Section: Batch Experiments On Mixed Liquor From Municipal Wastewater mentioning

confidence: 99%

Potential of Rhodobacter capsulatus Grown in Anaerobic-Light or Aerobic-Dark Conditions as Bioremediation Agent for Biological Wastewater Treatments

Costa

Ganzerli²,

Rugiero

et al. 2017

Water

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Abstract:The use of microorganisms to clean up wastewater provides a cheaper alternative to the conventional treatment plant. The efficiency of this method can be improved by the choice of microorganism with the potential of removing contaminants. One such group is photosynthetic bacteria. Rhodobacter capsulatus is a purple non-sulfur bacterium (PNSB) found to be capable of different metabolic activities depending on the environmental conditions. Cell growth in different media and conditions was tested, obtaining a concentration of about 10 8 CFU/mL under aerobic-dark and 10 9 CFU/mL under anaerobic-light conditions. The biomass was then used as a bioremediation agent for denitrification and nitrification of municipal wastewater to evaluate the potential to be employed as an additive in biological wastewater treatment. Inoculating a sample of mixed liquor withdrawn from the municipal wastewater treatment plant with R. capsulatus grown in aerobic-dark and anaerobic-light conditions caused a significant decrease of N-NO 3 (>95%), N-NH 3 (70%) and SCOD (soluble chemical oxygen demand) (>69%), independent of the growth conditions. A preliminary evaluation of costs indicated that R. capsulatus grown in aerobic-dark conditions could be more convenient for industrial application.

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Factors impacting biotransformation kinetics of trace organic compounds in lab-scale activated sludge systems performing nitrification and denitrification

Cited by 49 publications

References 44 publications

New insights into the transformation of trimethoprim during biological wastewater treatment

New insights into the transformation of trimethoprim during biological wastewater treatment

Removal of Antibiotics in Biological Wastewater Treatment Systems—A Critical Assessment Using the Activated Sludge Modeling Framework for Xenobiotics (ASM-X)

Potential of Rhodobacter capsulatus Grown in Anaerobic-Light or Aerobic-Dark Conditions as Bioremediation Agent for Biological Wastewater Treatments

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