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

State of Art about water uses and wastewater management in Lebanon

12 p.International audienceThis paper shows the real situation about management of water and wastewater in Lebanon and focuses on problems related to urban water pollution released in environment. Water and wastewater infrastructures have been rebuilt since 1992. However, wastewater management still remains one of the greatest challenges facing Lebanese people, since water supply projects have been given priority over wastewater projects. As a consequence of an increased demand of water by agricultural, industrial and household sectors in the last decade, wastewater flows have been increased. In this paper, the existing wastewater treatment plants (WWTP) operating in Lebanon are presented. Most of them are small-scale community-based ones, only two large-scale plants, constructed by the government, are currently operational. Lebanese aquatic ecosystems are suffering from the deterioration of water quality because of an insufficient treatment of wastewater, which is limited mostly to pre-treatment processes. In fact, domestic and industrial effluents are mainly conducted together in the sewer pipes to the WWTP before being discharged, without adequate treatment into the rivers or directly into the Mediterranean Sea. Such discharges are threatening the coastal marine ecosystem in the Mediterranean basin. This paper aims at giving the current state of knowledge about water uses and wastewater management in Lebanon. The main conclusion drawn from this state of art is a lack of data. In fact, the available data are limited to academic researches without being representative on a national scale

Efficiency of source control systems for reducing runoff pollutant loads: Feedback on experimental catchments within Paris conurbation.

International audience: Three catchments, equipped with sustainable urban drainage systems (SUDS: vegetated roof, underground pipeline or tank, swale, grassed detention pond) for peak flow mitigation, have been compared to a reference catchment drained by a conventional separate sewer system in terms of hydraulic behaviour and discharged contaminant fluxes (organic matter, organic micropollutants, metals). A runoff and contaminant emission model has been developed in order to overcome land use differences. It has been demonstrated that the presence of peak flow control systems induces flow attenuation even for frequent rain events and reduces water discharges at a rate of about 50% depending on the site characteristics. This research has also demonstrated that this type of SUDS contributes to a significant reduction of runoff pollutant discharges, by 20%-80%. This level of reduction varies depending on the considered contaminant and on the design of the drainage system but is mostly correlated with the decrease in runoff volume. It could be improved if the design of these SUDS focused not only on the control of exceptional events but also targeted more explicitly the interception of frequent rain events

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

Polar polycyclic aromatic compounds (polar PACs) occurence and origin : issues and requirements for future investigations

International audiencePolar polycyclic aromatic compounds (polar PACs) are less known than PAHs, and neither monitored nor regulated anywhere, despite their potential harmfulness and greater mobility. They were rarely intentionally produced, and they occur mainly as PAH metabolites. They often occur at the same sites (gasworks, coke plants, wood treatment sites) as PAHs and other PACs but have been mostly overlooked. Other potential sites include wood tar production and oil refineries or storage affected by accidents. PAH remediation treatments, such as thermal desorption or chemical oxidation may have promoted the formation of oxy-PACs while applied, along with the mitigation of regulated PAHs. According to existing regulations, the site contamination level related to the sum of PAH was reduced, but the actual risk may have been increased. In order to identify potential risks, the monitoring of oxy-PACs is required. However, analytical capabilities are not developed, data on oxy-PACs are scarce and research is still needed. Available results from contaminated site databases and from our investigations suggest that polar PACs may constitute between 10 and 20% of total PACs in soil, and their occurrence in shallow groundwater is often overlooked at contaminated sites. Their potential impact on risk analysis is largely unknown and may be underestimated, as their transfer properties are by far less favourable than those of PAHs. Their monitoring would require analysis standards and commercially available analytical services before any regulatory approach is undertaken. This is most important for sustainable remediation of PAH-contaminated sites

Effect of remediation treatments on Polar PACs in soils : degradation vs. formation

International audienceThe evaluation of the efficiency of remediation processes (thermal desorption, ISCO, bioremediation…) of PAH polluted soil is generally based on the measurement of specific parameters (i.e. 16 PAH US-EPA). Such limited characterisations do not allow evaluating the potential formation of organic by-products (especially Polycyclic Aromatic Compounds-PAC). Different remediation treatments, most commonly used and that may be the most problematic regarding O-PAH production, have been applied to three representatives PAH contaminated soils (former gasworks, coke oven plants and wood preservation facilities soils). These treatments include chemical oxidation (hydroperoxyde oxidation (H 2 O 2), Fenton like oxidation using magnetite as catalyst and permanganate (MnO 4-)) and biological treatment. The experimental results with chemical treatment show that the polar oxy-PAHs were removed more slowly than the PAHs in all chemical treatments, indicating that O-PACs were simultaneous generated during the oxidation (especially for permanganate treatment). The effect was most obvious when considering the PAC contribution to the total Extractable Organic Matter (EOM). The microbiological treatment performed on these soils shows a removal of PAHs with a removal rates controlled by the availability of the pollution. Polar PACs remediation followed the same trends as the PAHs in the coke oven soils and the gasworks soil. However, in the wood preservation soil, the removal rates of the polar PACs were significantly lower than of the PAHs suggesting a simultaneous formation of polar PACs as a result of the extensive transformation of PAHs in this soil

Quantitative monitoring of dissolved gases in a flooded borehole: calibration of the analytical tools

Gas monitoring is a prerequisite to understanding the exchange, diffusion, and migration processes of natural gases within underground environments, which are involved in several applications such as geological sequestration of CO2. In this study, three different techniques (micro-GC, infrared, and Raman spectroscopies) were deployed on an experimental flooded borehole for monitoring purposes after CO2 injection. The aim was to develop a real-time chemical monitoring device to follow dissolved gas concentrations by measurements in water inside the borehole but also at the surface through a gas collection system in equilibrium with the borehole water. However, all three techniques must be calibrated to provide the most accurate quantitative data. For this, a first step of calibration in the laboratory was carried out. A new calibrations were required to determine partial pressure and/or concentrations of gases in water or in the gas collection system. For gas phase analysis, micro-GC, FTIR spectroscopy, and Raman spectroscopy were compared. New calibration of the micro-GC was done for CO2, CH4, and N2 with uncertainty from ±100 ppm to 1.5 mol% depending on the bulk concentration and the type of gas. The FTIR and Raman spectrometers were previously calibrated for CO2, and CO2, N2, O2, CH4, and H2O, respectively with an accuracy of 1–6% depending on concentration scale, gas and spectrometer. Dissolved CO2 in water was measured using a Raman spectrometer equipped with an immersion probe. The uncertainty on the predicted dissolved CO2 concentration and partial pressure was ±0.003 mol·kg−1 and ±0.05 bar, respectively

Characterization of the macromolecular fractions of PAH contaminated soils using high-resolution mass spectrometry

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Thermodesorption – gas chromatography – mass spectrometry (Td-GC-MS) as a new tool to measure organic contaminant availability

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Thermal method as a new approach to link organic pollutant availability and reactivity in contaminated soils

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