Discharges of endocrine disrupting chemicals by combined sewer overflows into receiving water: case-study of the Paris conurbation

8 p.International audienceAlkylphenol ethoxylate (APEOs) and bisphenol A (BPA) are well known as endocrine disrupting compounds. Among sources of these compounds within receiving waters, wastewater treatment plant effluents have been widely studied. However, Although APEOs and BPA are regularly quantified within wastewater and to a lesser extent in runoff, few studies deal with their discharges by combined sewer overflows. In this context, this study was launched to investigate the concentrations and the mass loads discharged per year by CSO in the Seine River. Therefore, discharges occurring at the one of the most important CSOs of Paris conurbation from June to November 2010 were sampled. During this period, eight events were collected by automatic samplers and even mean sample were analyzed in laboratory using liquid chromatography coupled to a tandem mass spectrometry. The first results highlight an important contamination of CSOs by BPA and levels of APEOs close to those reported in wastewaters. At the annually scale and according to our mass load calculation, CSOs do not appear as a relevant source of BPA and APEOs within the Seine River

Determination of in-situ biodegradation rate constants of nonylphenolic compounds in the Seine River

Assessing the fate of endocrine disrupting compounds (EDC) in the environment is currently a key issue for determining their impacts on aquatic ecosystems. The 4 nonylphenol (4-NP) is a well known EDC. It results from the biodegradation of surfactant nonylphenol ethoxylates (NPEO). Biodegradation mechanisms of NPEO are well documented (Giger et al. 2009) but their rate constants have been mainly determined through laboratory experiments. To our knowledge only Jonkers et al. (2005) evaluate NPEO biodegradation rate constants according to field measurements. Their study was carried out in an estuary (salt water) and has to be confirmed for freshwater. This study aims at evaluating the in-situ biodegradation of 4-NP, nonylphenol monoethoxylate (NP1EO) and nonylphenolic acetic acid (NP1EC). Two innovative sampling campaigns were carried out on the Seine River in July and September 2011, from Maisons-Laffitte to Triel-sur-Seine (along a 40km-transect downstream of Paris City). Their results were used for calibrating a sub-model of NPEO biodegradation of the hydrodynamic-biogeochemical model of the Seine River (PROSE, Even et al. 1998). Sampling times were estimated according to the Seine River velocity in order to follow the same volume of water. Simultaneously, during the September sampling campaign, small scale spatial and temporal variabilities of nonylphenolic compounds concentrations were assessed. Biodegradation rate constants of 4-NP, NP1EO and NP1EC between July and September varied greatly. Although the biodegradation rate constants in July were especially high (higher than 1 d 1), those obtained in September were smaller but consistent with the literature. This variability is probably linked to the biogeochemical behaviour of the Seine River. Indeed, the July sampling campaign took place at the end of an algal bloom leading to an unusual bacterial biomass while the September campaign was carried out during an "usual" biogeochemical state. This study provides relevant information regarding biodegradation rate constants of alkylphenols in an aquatic environment. Such data may be very helpful in the future to better understand the fate and transfer of nonylphenolic compounds at the catchment basin scale

Meta-analysis of environmental contamination by phtalates

Introduction: Phthalate Acid Esters (PAE), commonly named Phthalates, are toxics classified as endocrine-disrupting compounds; they are primarily used as additives to improve the flexibility in polyvinyl chloride. Occurrence: Many studies have reported the occurrence of phthalates in different environmental matrices, however none of these studies has yet establish a complete overview for those compounds in the water cycle within an urban environment. This review summarizes PAE concentrations for all environmental media throughout the water cycle, from atmosphere to receiving waters. Once the occurrences of compounds have been evaluated for each environmental compartment (urban wastewater, wastewater treatment plants, atmosphere and the natural environment), data are reviewed in order to identify the fate of PAE in the environment and establish whether geographical and historical trends exist. Indeed, geographical and historical trends appear between Europe and other countries such as USA/Canada and China, however they remain location-dependent. Discussion: This study aimed at identifying both the correlations existing between environmental compartments and the processes influencing the fate and transport of these contaminants into the environment. In Europe, the concentrations measured in waterways today represent the background level of contamination, which provides evidence of a past diffuse pollution. In contrast, an increasing trend has actually been observed for developing countries, especially for China

Modelling the fate of nonylphenolic compounds in the Seine River -- part 1: Determination of in-situ attenuation rate constants

International audienceAssessing the fate of endocrine disrupting compounds (EDCs) in the environment is currently a key issue for determining their impacts on aquatic ecosystems. The 4-nonylphenol (4-NP) is a well known EDC and results from the biodegradation of surfactant nonylphenol ethoxylates (NPnEOs). Fate mechanisms of NPnEO are well documented but their rate constants have been mainly determined through laboratory experiments. This study aims at evaluating the in-situ fate of 4-NP, nonylphenol monoethoxylate (NP1EO) and nonylphenolic acetic acid (NP1EC). Two sampling campaigns were carried out on the Seine River in July and September 2011, along a 28 km-transect downstream Paris City. The field measurements are used for the calibration of a sub-model of NPnEO fate, included into a hydro-ecological model of the Seine River (ProSe). The timing of the sampling is based on the Seine River velocity in order to follow a volume of water. Based on our results, in-situ attenuation rate constants of 4-NP, NP1EO and NP1EC for both campaigns are evaluated. These rate constants vary greatly. Although the attenuation rate constants in July are especially high (higher than 1 d− 1), those obtained in September are lower and consistent with the literature. This is probably due to the biogeochemical conditions in the Seine River. Indeed, the July sampling campaign took place at the end of an algal bloom leading to an unusual bacterial biomass while the September campaign was carried out during common biogeochemical status. Finally, the uncertainties on measurements and on the calibration parameters are estimated through a sensitivity analysis. This study provides relevant information regarding the fate of biodegradable pollutants in an aquatic environment by coupling field measurements and a biogeochemical model. Such data may be very helpful in the future to better understand the fate of nonylphenolic compounds or any other pollutants at the basin scale

Priority pollutants in urban stormwater: Part 2 - Case of combined sewers

Postprint de l'article : Priority pollutants in urban stormwater in urban stormwater - Case of combined sewers. J. Gasperi, S. Zgheib, M. Cladière, V. Rocher, R. Moilleron, G. Chebbo. Water research, special issue on urban stormwater 2011International audienceThis study has evaluated the quality of combined sewer overflows (CSO) in an urban watershed, such as Paris, by providing accurate data on the occurrence of priority pollutants (PPs) and additional substances, as well as on the significance of their concentrations in comparison with wastewater and stormwater. Of the 88 substances monitored, 49 PPs were detected, with most of these also being frequently encountered in wastewater and stormwater, thus confirming their ubiquity in urban settings. For the majority of organic substances, concentrations range between 0.01 and 1 µg.l-1, while metals tend to display concentrations above 10 µg.l-1. Despite this ubiquity, CSO, wastewater and stormwater feature a number of differences in both their concentration ranges and pollutant patterns. For most hydrophobic organic pollutants and some particulate-bound metals, CSOs exhibit higher concentrations than those found in stormwater and wastewater, due to the contribution of in-sewer deposit erosion. For pesticides and Zn, CSOs have shown concentrations close to those of stormwater, suggesting runoff as the major contributor, while wastewater appears to be the main source of volatile organic compounds. Surprisingly, similar concentration ranges have been found for DEHP and tributyltin compounds in CSOs, wastewater and stormwater. The last section of this article identifies substances for which CSO discharges might constitute a major risk of exceeding Environmental Quality Standards in receiving waters and moreover indicates a significant risk for PAHs, tributyltin compounds and chloroalkanes. The data generated during this survey can subsequently be used to identify PPs of potential significance that merit further investigation

Alkylphenolic compounds and bisphenol A contamination within a heavily urbanized area: case study of Paris.

International audienceThis study evaluates the influence of a heavily urbanized area (Paris Metropolitan area), on receiving water contamination by both bisphenol A (BPA) and alkylphenol ethoxylate (APE) biodegradation product. The study began by investigating concentrations within urban sources. In addition to the more commonly studied wastewater treatment plant effluent, wet weather urban sources (including combined sewer overflows, urban runoff, and total atmospheric fallout) were considered. The initial results highlight a significant contamination of all urban sources (from a few nanograms per liter in atmospheric fallout to several micrograms per liter in the other sources) with clearly distinguishable distribution patterns. Secondly, concentration changes along the Seine River from upstream of the Paris Metropolitan area to downstream were investigated. While the concentrations of BPA and nonylphenoxy acetic acid (NP(1)EC) increase substantially due to urban sources, the 4-nonylphenol concentrations remain homogeneous along the Seine. These results suggest a broad dissemination of 4-nonylphenol at the scale of the Seine River basin. Moreover, the relationship between pollutant concentrations and Seine River flow was assessed both upstream and downstream of the Paris conurbation. Consequently, a sharp decrease in dissolved NP(1)EC concentrations relative to Seine River flow underscores the influence of single-point urban pollution on Seine River contamination. Conversely, dissolved 4-nonylphenol concentrations serve to reinforce the hypothesis of its widespread presence at the Seine River basin scale

Biofiltration vs conventional activated sludge plants: what about priority and emerging pollutants removal?

International audience: This paper compares the removal performances of two complete wastewater treatment plants (WWTPs) for all priority substances listed in the Water Framework Directive and additional compounds of interest including flame retardants, surfactants, pesticides, and personal care products (PCPs) (n = 104). First, primary treatments such as physicochemical lamellar settling (PCLS) and primary settling (PS) are compared. Similarly, biofiltration (BF) and conventional activated sludge (CAS) are then examined. Finally, the removal efficiency per unit of nitrogen removed of both WWTPs for micropollutants is discussed, as nitrogenous pollution treatment results in a special design of processes and operational conditions. For primary treatments, hydrophobic pollutants (log K ow > 4) are well removed (>70 %) for both systems despite high variations of removal. PCLS allows an obvious gain of about 20 % regarding pollutant removals, as a result of better suspended solids elimination and possible coagulant impact on soluble compounds. For biological treatments, variations of removal are much weaker, and the majority of pollutants are comparably removed within both systems. Hydrophobic and volatile compounds are well (>60 %) or very well removed (>80 %) by sorption and volatilization. Some readily biodegradable molecules are better removed by CAS, indicating a better biodegradation. A better sorption of pollutants on activated sludge could be also expected considering the differences of characteristics between a biofilm and flocs. Finally, comparison of global processes efficiency using removals of micropollutants load normalized to nitrogen shows that PCLS + BF is as efficient as PS + CAS despite a higher compactness and a shorter hydraulic retention time (HRT). Only some groups of pollutants seem better removed by PS + CAS like alkylphenols, flame retardants, or di-2-ethylhexyl phthalate (DEHP), thanks to better biodegradation and sorption resulting from HRT and biomass characteristics. For both processes, and out of the 68 molecules found in raw water, only half of them are still detected in the water discharged, most of the time close to their detection limit. However, some of them are detected at higher concentrations (>1 μg/L and/or lower than environmental quality standards), which is problematic as they represent a threat for aquatic environment

Removal of emerging micropollutants from wastewater discharges by powdered and micro-grain activated carbon - Progress of the CarboPlus® project

International audienceThe implementation of a tertiary treatment in conventional wastewater treatment plants is more and more considered by managers to reduce the emerging contaminant discharges into the aquatic environment. In this context, a collaboration between the public sanitation service of Paris conurbation and the Water Environment and Urban Systems laboratory has been initiated since 2013 to study at large scale a pilot (CarboPlus® - SAUR/STEREAU) based on a high concentration fluidized bed activated carbon reactor (>100 kg/m3) with continuous fresh activated carbon injection. The objectives of this project are to i) characterize the efficiency of the process for emerging pollutants for powdered (PAC) and micro-grain (µGAC) activated carbons, ii) characterize the parameters influencing the sorption mechanism (organic matter, operating parameters, activated carbon structure and properties, etc.) and iii) identify the eventual improvements of the conventional quality parameters.In addition to the 14 campaigns already performed in 2013 in PAC configuration, 14 campaigns have been planed in 2014 (8 already performed) to study the fate of 131 micropollutants, including 61 pharmaceuticals and hormones and 70 other emerging pollutants, in addition to conventional wastewater parameters. This presentation aims at displaying the pilot efficiency in µGAC configuration and comparing it to the PAC configuration. The use of µGAC instead of PAC has several operational and economical advantages, but this new type of carbon was never tested with wastewater. Based on the first 8 campaigns, the results tend to indicate that the pilot is as efficient with µGAC than with PAC. In particular, ketoprofen, paracetamol, ibuprofen, ofloxacin, ciprofloxacin, trimethoprim, roxithromycin, atenolol, propranolol, carbamazepine, oxazepam, lorazepam and estrone have removals higher than 80% in average. In addition, first results on the other emerging micropollutants show high or very high removals for pesticides (60-95%), bisphenol A (60-90%), alkylphenols (60-95%), PFOS (75-95%) and X-ray contrast agents (50-70%). Moreover, the high solid retention time (60-90 days) of the µGAC leads to a biological activity within the reactor, as displayed by NO2- (65-99%) and NH4+ (20-70%) removals. However, the results are still partial at this stage of the project, another µGAC dose is currently tested on the pilot and complementary lab-scale tests are still performed to better understand the sorption mechanism

A Methodology to Characterize Riverine Macroplastic Emission Into the Ocean

Land-based macroplastic is considered one of the major sources of marine plastic debris. However, estimations of plastic emission from rivers into the oceans remain scarce and uncertain, mainly due to a severe lack of standardized observations. To properly assess global plastic fluxes, detailed information on spatiotemporal variation in river plastic quantities and composition are urgently needed. In this paper, we present a new methodology to characterize riverine macroplastic dynamics. The proposed methodology was applied to estimate the plastic emission from the Saigon River, Vietnam. During a 2-week period, hourly cross-sectional profiles of plastic transport were made across the river width. Simultaneously, sub-hourly samples were taken to determine the weight, size and composition of riverine macroplastics (>5 cm). Finally, extrapolation of the observations based on available hydrological data yielded new estimates of daily, monthly and annual macroplastic emission into the ocean. Our results suggest that plastic emissions from the Saigon River are up to four times higher than previously estimated. Importantly, our flexible methodology can be adapted to local hydrological circumstances and data availability, thus enabling a consistent characterization of macroplastic dynamics in rivers worldwide. Such data will provide crucial knowledge for the optimization of future mediation and recycling efforts