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Tel Aviv, Israel

Gasser G.,Hebrew University of Jerusalem | Pankratov I.,Israeli Water Authority | Elhanany S.,Israeli Water Authority | Werner P.,Hebrew University of Jerusalem | And 4 more authors.
Chemosphere | Year: 2012

The stereoselectivity of R,. S-venlafaxine and its metabolites R,. S-O-desmethylvenlafaxine, N-desmethylvenlafaxine, O,. N-didesmethylvenlafaxine, N,. N-didesmethylvenlafaxine and tridesmethylvenlafaxine was studied in three processes: (i) anaerobic and aerobic laboratory scale tests; (ii) six wastewater treatment plants (WWTPs) operating under different conditions; and (iii) a variety of wastewater treatments including conventional activated sludge, natural attenuation along a receiving river stream and storage in operational and seasonal reservoirs. In the laboratory and field studies, the degradation of the venlafaxine yielded O-desmethylvenalfaxine as the dominant metabolite under aerobic and anaerobic conditions. Venlafaxine was almost exclusively converted to O-desmethylvenlafaxine under anaerobic conditions, but only a fraction of the drug was transformed to O-desmethylvenlafaxine under aerobic conditions. Degradation of venlafaxine involved only small stereoisomeric selectivity. In contrast, the degradation of O-desmethylvenlafaxine yielded remarkable S to R enrichment under aerobic conditions but none under anaerobic conditions. Determination of venlafaxine and its metabolites in the WWTPs agreed well with the stereoselectivity observed in the laboratory studies. Our results suggest that the levels of the drug and its metabolites and the stereoisomeric enrichment of the metabolite and its parent drug can be used for source tracking and for discrimination between domestic and nondomestic wastewater pollution. This was indeed demonstrated in the investigations carried out at the Jerusalem WWTP. © 2012 Elsevier Ltd. Source


Rona M.,Hebrew University of Jerusalem | Gasser G.,Hebrew University of Jerusalem | Negev I.,Mekorot | Pankratov I.,Israeli Water Authority | And 3 more authors.
Water Resources Research | Year: 2014

Wastewater recharge facilities are often used as a final water treatment before the discharge to the sea or before water reclamation. These facilities are often located in active aquifers that supply drinking water. Thus, leakage from the water recharge facility and gradual expansion of the underground wastewater plume are of considerable health concern. Hydrological modeling of water recharge systems are widely used as operational and predictive tools. These models rely on distributed water head monitoring and at least one chemical or physical tracer to model solutes' transport. Refractory micropollutants have proven useful in qualitative identification of pollution leakages and for quantification of pollution to a specific site near water recharge facilities. However, their usefulness as tracers for hydrological modeling is still questionable. In this article, we describe a long term, 3-D hydraulic model of a large-scale wastewater effluents recharge system in which a combination of chloride and a refractory micropollutant, carbamazepine is used to trace the solute transport. The combination of the two tracers provides the model with the benefits of the high specificity of the carbamazepine and the extensive historic data base that is available for chloride. The model predicts westward expansion of the pollution plume, whereas a standing front is formed at the east. These trends can be confirmed by the time trace of the carbamazepine concentrations at specific locations. We show that the combination of two tracers accounts better (at least at some locations) for the evolution of the pollution plume than a model based on chloride or carbamazepine alone. Key Points First use of a micropollutant tracer for calibration of 3-D hydrological model Carbamazepine lacks historic data; was combined with Cl- for the calibration Artificial tracer was used to quantify water mixing rather than solute mixing © 2014. American Geophysical Union. All Rights Reserved. Source


Gasser G.,Hebrew University of Jerusalem | Rona M.,Hebrew University of Jerusalem | Voloshenko A.,Hebrew University of Jerusalem | Shelkov R.,Israeli Water Authority | And 4 more authors.
Environmental Science and Technology | Year: 2010

Quantitative criteria for selection of tracers for assessment of mixing of wastewater and pristine water are proposed and evaluated for leakage from a wastewater effluent recharge system to nearby pristine water wells and the dilution of the effluents in a reclamation well by pristine water from the surrounding aquifer. Two molecular tracers were compared: carbamazepine, an organic drug whose refractory behavior was evaluated on-site, and chloride, a widely used conservative tracer. The mixing ratios and the corresponding uncertainty levels in their calculation were evaluated using actual field data. Uncertainty level analysis illuminates the effects of the analytical errors in the determination of trace micropollutants on one hand and the high level of chloride in the background on the other. Uncertainty level calculations revealed that chloride is a somewhat better tracer for the estimation of the dilution of wastewater by flow from a pristine aquifer, whereas carbamazepine is a much better tracer for the calculation of wastewater contamination of nearby drinking water wells. Surprisingly, we show that even when carbamazepine degrades to a large and unknown extent, it can still be used to estimate accurately the probability that a site is contaminated by a wastewater stream. © 2010 American Chemical Society. Source

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