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Colombes, France

Gasperi J.,University Paris Est Creteil | Laborie B.,SIAAP | Rocher V.,SIAAP
Chemical Engineering Journal | Year: 2012

This study aims at examining the performance of the ballasted flocculation unit (BFU) on treating combined sewer overflows (CSOs) and the evaluation depends on the values obtained of routine wastewater parameters and on the contents of a large broad spectrum of pollutants. Accordingly, the full-scale BFU at the largest wastewater treatment plant in Europe (Seine Aval plant near Paris, France) is investigated during three sampling campaigns. Of the 97 molecules targeted, 57 substances including 18 priority substances and 11 priority hazardous substances were detected in the BFU influents confirming that wet weather flow (WWF) treatment has definitively proven to be necessary. The WWF treatment by ballasted flocculation appears as a promising but not a fully adapted technology for use in densely urbanized areas to considerably mitigate the CSO impacts. On operating at the optimal chemical and sand doses, this process appears to be a suitable technology to remove particles, carbonaceous and phosphorous pollutants, particulate metals and most of hydrophobic organic compounds whilst nitrogenous pollutants and most of hydrophilic compounds are from poorly (<20%) to moderately (<50%) removed. The BFU appeared less sensitive to the influent concentration fluctuations and hydraulic peak load (at the scale of the campaigns considered) than to the adjustments of chemical doses and sand injection. Investigating the performance of such process, could serve to develop management strategies that enable mitigating the impacts of CSOs on receiving water in compliance with the Water Framework Directive objectives. © 2012 Elsevier B.V. Source

Berge A.,Laboratoire Central Of La Prefecture Of Police | Berge A.,University Paris Est Creteil | Gasperi J.,University Paris Est Creteil | Rocher V.,SIAAP | And 3 more authors.
Science of the Total Environment | Year: 2014

Phthalates and alkylphenols are toxics classified as endocrine disrupting compounds (EDCs). They are of particular concern due to their ubiquity and generally higher levels found in the environment comparatively to other EDCs. Industrial and domestic discharges might affect the quality of receiving waters by discharging organic matter and contaminants through treated waters and combined sewer overflows. Historically, industrial discharges are often considered as the principal vector of pollution in urban areas. If this observation was true in the past for some contaminants, no current data are today available to compare the quality of industrial and domestic discharges as regards EDCs. In this context, a total of 45 domestic samples as well as 101 industrial samples were collected from different sites, including 14 residential and 33 industrial facilities. This study focuses more specifically on 4 phthalates and 2 alkylphenols, among the most commonly studied congeners. A particular attention was also given to routine wastewater quality parameters. For most substances, wastewaters from the different sites were heavily contaminated; they display concentrations up to 1200. μg/l for di-(2-ethylhexyl) phthalate and between 10 and 100. μg/l for diethyl phthalate and nonylphenol. Overall, for the majority of compounds, the industrial contribution to the flux of contaminant reaching the wastewater treatment plants ranges between 1 and 3%. The data generated during this work constitutes one of the first studies conducted in Europe on industrial fluxes for a variety of sectors of activity. The study of the wastewater contribution was used to better predict the industrial and domestic contributions at the scale of a huge conurbation heavily urbanized but with a weak industrial cover, illustrated by Paris. Our results indicate that specific investigations on domestic discharges are necessary in order to reduce the release of phthalates and alkylphenols in the sewer systems for such conurbations. © 2014 Elsevier B.V. Source

The SIAAP (Syndicat Interdépartemental pour l'Assainissement de l'Agglomération Parisienne - Interdepartmental union for the sanitation of the Paris Conurbation), that manages the sanitation of nearly 9 million Ile-de-France residents, is faced with the need to renovate, modernise and backfit its transport and treatment facilities. In-depth considerations, focusing in particular on energy expenditure, were the driving force behind the SIAAP's strategy to optimise its production and development of biogas recoverable from sludge generated by waste water treatment. This presentation describes and compares the various methods of recovery and reuse of this biogas for energy purposes in view of identifying the best application at each of the 2 largest remediation plants. Reuse internal to the site traditionally concerns selfconsumed heat and electricity production, but recent regulatory measures point to possible optimisation by re-injecting the electricity into the ErDF grid, or the purified biogas into the GDF network, or even to the production of BioLNG liquefied methane for an evolving market. The economic, legal and environment context is considered in light of the historical and geographical situation and of the plants' treatment processes. Source

Gasperi J.,University Paris Est Creteil | Zgheib S.,University Paris Est Creteil | Zgheib S.,Lebanese Center for Water Management and Conservation | Cladiere M.,University Paris Est Creteil | And 3 more authors.
Water Research | Year: 2012

This study has evaluated the quality of combined sewer overflows (CSOs) 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 1μgl-1, while metals tend to display concentrations above 10μgl-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. © 2011 Elsevier Ltd. Source

Vilmin L.,MINES ParisTech | Flipo N.,MINES ParisTech | Escoffier N.,University of Paris Pantheon Sorbonne | Rocher V.,SIAAP | Groleau A.,University Paris Diderot
Global Biogeochemical Cycles | Year: 2016

Fluvial networks play an important role in regional and global carbon (C) budgets. The Seine River, from the Paris urban area to the entrance of its estuary (220 km), is studied here as an example of a large human-impacted river system subject to temperate climatic conditions. We assess organic C (OC) budgets upstream and downstream from one of the world's largest wastewater treatment plants and for different hydrological conditions using a hydrobiogeochemical model. The fine representation of sediment accumulation on the river bed allows for the quantification of pelagic and benthic effects on OC export toward the estuary and on river metabolism (i.e., net CO2 production). OC export is significantly affected by benthic dynamics during the driest periods, when 25% of the inputs to the system is transformed or stored in the sediment layer. Benthic processes also substantially affect river metabolism under any hydrological condition. On average, benthic respiration accounts for one third of the total river respiration along the studied stretch (0.27 out of 0.86 g C m-2 d-1). Even though the importance of benthic processes was already acknowledged by the scientific community for headwater streams, these results stress the major influence of benthic dynamics, and thus of physical processes such as sedimentation and resuspension, on C cycling in downstream river systems. It opens the door to new developments in the quantification of C emissions by global models, whereby biogeochemical processing and benthic dynamics should be taken into account. ©2016. American Geophysical Union. Source

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