Direction du Developpement et de la Prospective

Colombes, France

Direction du Developpement et de la Prospective

Colombes, France
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Passerat J.,Free University of Colombia | Ouattara N.K.,Free University of Colombia | Mouchel J.-M.,University Pierre and Marie Curie | Vincent Rocher,Direction du Developpement et de la Prospective | Servais P.,Free University of Colombia
Water Research | Year: 2011

For a better understanding of the short and mid-term impacts of a combined sewer overflow (CSO) on the microbiological quality of the receiving river, we studied the composition of a CSO discharge and monitored during several hours the changes in the concentration of fecal indicator bacteria (FIB) in the impacted river water mass. The CSO occurred at the Clichy outfall (Paris agglomeration, France) in summer 2008 as a result of the most intense rainfall of the year. In 6h, 578, 705 m3 of sewage and 124 t of suspended matter (SM) were discharged into the Seine River. The CSO contained 1.5 × 106 E. coli and 4.0 × 105 intestinal enterococci per 100 mL on average, and 77% of the E. coli were attached to SM. It was estimated that 89% of the CSO discharge was contributed by surface water runoff, and that resuspension of sewer sediment contributed to ∼75% of the SM, 10-70% of the E. coli and 40-80% of the intestinal enterococci. Directly downstream from the CSO outfall, FIB concentrations in the impacted water mass of the Seine River (2.9 × 105 E. coli and 7.6 × 104 intestinal enterococci per 100 mL) exceeded by two orders of magnitude the usual dry weather concentrations. After 13-14 h of transit, these concentrations had decreased by 66% for E. coli and 79% for intestinal enterococci. This decline was well accounted for by our estimations of dilution, decay resulting from mortality or loss of culturability and sedimentation of the attached fraction of FIB. © 2010 Elsevier Ltd.

Dris R.,University Paris Est Creteil | Gasperi J.,University Paris Est Creteil | Rocher V.,Direction du Developpement et de la Prospective | Saad M.,University Paris Est Creteil | And 2 more authors.
Environmental Chemistry | Year: 2015

Environmental context Plastics production has increased considerably in recent years, leading to pollution by plastics, including microplastics (comprising particles smaller than 5mm). This work addresses the issue of microplastics from urban sources and in receiving waters in Greater Paris. Microplastics were found in all urban compartments investigated, namely atmospheric fallout, waste- and treated water, and surface water. Abstract This study investigates the microplastic contamination of both urban compartments (wastewater and total atmospheric fallout) and surface water in a continental environment. These first investigations on an urban environment confirm the presence of microplastics in sewage, fresh water and total atmospheric fallout and provide knowledge on the type and size distribution of microplastics in the 100-5000-μm range. For the first time, the presence of microplastics, mostly fibres, is highlighted in total atmospheric fallout (29-280particlesm-2day-1). High levels of fibres were found in wastewater (260-320×103particlesm-3). In treated effluent, the contamination significantly decreased to 14-50×103particlesm-3. In the River Seine, two sampling devices were used to collect both large and small microplastic particles: (i) a plankton net (80-μm mesh), and (ii) a manta trawl (330-μm mesh). Sampling with the plankton net showed a predominance of fibres, with concentrations ranging from 3 to 108particlesm-3. A greater diversity of both microplastic shapes and types was found during manta trawl sampling but at much lower concentrations (0.28-0.47particlesm-3). This combined approach could be relevant and implemented in future studies to provide an accurate overview of microplastic distribution in freshwater. © CSIRO 2015.

Radomski N.,University Paris Est Creteil | Betelli L.,University Paris Est Creteil | Moilleron R.,University Paris Est Creteil | Haenn S.,Eau de Paris | And 5 more authors.
Environmental Science and Technology | Year: 2011

Mycobacteria are waterborne emerging pathogens causing infections in human. Mycobacteria have been previously isolated from wastewater and sludge, but their densities were not estimated due to cultural biases. In order to evaluate the impact of wastewater treatment processes on mycobacteria removal, we used a real time PCR method. First we compared six DNA extraction methods and second we used the more efficient DNA extraction procedure (i.e., enzymatic lysis combined with hexadecyltrimethylammonium bromide-NaCl procedure) in order to quantify Mycobacterium. With the aim to identify parameters that could serve as indicator of mycobacterial behavior, mycobacterial densities were measured in parallel to those of Escherichia coli and enterococci, and to concentrations of chemical parameters usually monitored in wastewater. Mycobacterium reached 5.5 x 105 ± 3.9 x 105 copies/L in the influent, but was not detected in the effluent after decantation and biofiltration. Most mycobacteria (98.6 ± 2.7%, i.e. 2.4 ± 0.7 log10) were removed by the physical-chemical decantation, and the remaining mycobacteria were removed by biofiltration. In contrast, enterococci and E. coli were lightly removed by decantation step and mainly removed by biofiltration. Our results showed that Mycobacterium corresponds to a hydrophobic behavior linked to insoluble compound removal, whereas enterococci and E. coli refer to hydrophilic behaviors linked to soluble compound removals. © 2011 American Chemical Society.

Escoffier N.,University Paris Diderot | Escoffier N.,Ecole Polytechnique Federale de Lausanne | Bensoussan N.,IPSO FACTO | Vilmin L.,MINES ParisTech | And 6 more authors.
Environmental Science and Pollution Research | Year: 2016

Large rivers are important components of the global C cycle. While they are facing an overall degradation of their water quality, little remains known about the dynamics of their metabolism. In the present study, we used continuous multi-sensors measurements to assess the temporal variability of gross primary production (GPP) and ecosystem respiration (ER) rates of the anthropized Seine River over an annual cycle. Downstream from the Paris urban area, the Seine River is net heterotrophic at the annual scale (−226 gO2 m−2 year−1 or −264 gC m−2 year−1). Yet, it displays a net autotrophy at the daily and seasonal scales during phytoplankton blooms occurring from late winter to early summer. Multivariate analyses were performed to identify the drivers of river metabolism. Daily GPP is best predicted by chlorophyll a (Chla), water temperature (T), light, and rainfalls, and the coupling of daily GPP and Chla allows for the estimation of the productivity rates of the different phytoplankton communities. ER rates are mainly controlled by T and, to a lesser extent, by Chla. The increase of combined sewer overflows related to storm events during the second half of the year stimulates ER and the net heterotrophy of the river. River metabolism is, thus, controlled at different timescales by factors that are affected by human pressures. Continuous monitoring of river metabolism must, therefore, be pursued to deepen our understanding about the responses of ecosystem processes to changing human pressures and climate. © 2016 Springer-Verlag Berlin Heidelberg

Pham H.N.,University Of Technologique Of Complegne | Mottelet S.,University Of Technologique Of Complegne | Schoefs O.,University Of Technologique Of Complegne | Pauss A.,University Of Technologique Of Complegne | And 5 more authors.
Eau, l'INDUSTRIE, les Nuisances | Year: 2010

Pursuant to the EU Water Framework Directive, the member states must restore a good ecological and chemical status of the surface water bodies within 15 years. As regards the nitrogen compounds, the threshold values not to be exceeded in the natural environment have been set to 2 mg.L-1, 0.5mg.L-1, 0.3 mg.L-1 et 50 mg.L-1for Kjeldahl nitrogen (NK), ammonia nitrogen (NH4 +), nitrite nitrogen (NO2 -) and nitrate nitrogen (NO3 -) respectively. Achieving these quality objectives implies that the wastewater treatment plant operators can control and monitor the concentrations of both nitrate and nitrite nitrogen in discharged water. Now, whereas the UV-type measuring apparatuses in current use enable to record the values for both species, they are not suitable for discriminating them. Against that background, the scientists from the Université Technologique de Compiègne and the Syndicat Interdépartemental pour l'Assainissement de l'Agglomération Parisienne have launched a study for testing and improving the on-line measuring apparatuses for NO3 -/NO2+ - As a matter of fact, a prototype on-line spectrophotometer discriminating the specific concentrations of nitrates and nitrites was tested and validated under actual operating conditions in a SIAAP's treatment plant (Seine Centre - Colombes - 800000 equivalent inhabitants). As evidenced by the results, there were good correlations between the estimated and experimental values ranging from 0.5 to 18 mg-N.L-1 for nitrates and from 0.5 to 5 mg-N.L-1 for nitrites. The discrimination between the nitrate and nitrite contents stems from the mathematical treatment of the UV spectrum rather than the resolution of the spectrophotometer. The outcome of the optimization and improvement of the spectral identification software has been weighed against the globally similar results given by such identification methods as PCR (Principal Component Regression) and PLS (Partial Least Squares).

Siaap is a local public entity established in 1970, which is in charge of transporting and treating the domestic, industrial and rainfall wastewaters from the Greater Paris area. For that purpose, it has five cleanup plants which are scattered over its collection basin, namely Seine-Aval, Seine-Amont, Seine-Centre, Seine-Grésillons and Marne-Aval. On December 2005, 23, the designation of the rivers Seine and Marne as an eutrophic sensitive area under the Urban Waste Water Treatment (UWWT) Directive compels yearly treatment performance levels to be met, for each of its plants, as regards total nitrogen (NGL 10 mg/L or a 70% abatement) and total phosphorus (P 1 mg/L or an 80% abatement), by the end of 2011. The regulatory permit orders, however, happen to be stricter that these yearly targets. Hence, in addition to substantially more binding yearly provisions, daily performance levels and stringent values are introduced for some plants. Likewise, the implementation of the Water Framework Directive (WFD) set goals regarding the natural environment for the achievement of the good ecological status, with a first deadline in 2015. They cover, in particular, as regards the biology-related parameters, ammoniacal nitrogen (NH4 +) and phosphorus (P). For these two parameters, the upper thresholds are set to 0.5 mg/L for NH4 and 0.2 mg/L for P, within the relevant water body and over 90% of measurements. The applications for permits which will be submitted by Siaap for the projects under development by that date are then quite restricted, since the intended objectives in the receiving waters are ultimately mostly transposed to the plant discharge level, once again in daily values. The pragmatic nature of the compliance monitoring procedures, which are more easily carried out at a daily or immediate level than on a yearly basis, or the expected low dilution within the environment and the desire to avoid any possible decommissioning and, beyond that, any decision taken by EU against France, are all reasons inciting the authorities which investigated these permits to strengthen the requirements in the discharge orders. They additionally put the client in a position where he may introduce stricter guarantees with the builders immediately upon the preparation of his projects and application files. Now, as regards biological processes, in combined sewer systems which are subject to the rainfall vagaries and the seasonal load fluctuations, the compliance with extreme daily performance requirements can hardly be guaranteed on a 365 days basis. Such techniques as biological phosphorus removal or upstream denitrification, with lower chemical reagents or power consumption rates and whose averaged operation over one year provide significant outputs, demonstrate their limitations when it comes to guaranteeing stringent daily values. Thus, that may lead to oversized equipment from the very outset of the design, to very high or even excessive reliability levels, to a nearly systematic use of the physico-chemical or downstream denitrification processes and to unnecessary amounts of reagents, in order to accommodate the vagaries involved by the future operation of these treatment plants.

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