Photoinductive degradation of two pesticies by natural dissolved organic matter under simulated sunlight

This study focused on the photochemical degradation of two herbicides : isoproturon (IPU) and diuron (DIU), that are two of the most abundant phenylureas found in surface and ground waters in France and classified as prioritary substances by European Directive (DCE). Sunlight irradiation was performed by a solar simulator Atlas Suntest CPS+ (290 nm < λ < 700 nm, 250 W/m2). Pesticide concentrations used in the experiments were approximately 1 µM. Photodegradation efficiencies have been measured for aqueous solutions of IPU and DIU, in the presence of DOM (20 mg/L) isolated from surface waters. LC-MS analysis was performed in order to identify possible photoproducts

PHOTODEGRADATION DE L'ESTRONE INDUITE PAR LA MATIERE ORGANIQUE NATURELLE DISSOUTE SOUS LUMIERE SOLAIRE

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PHOTOINDUCTIVE DEGRADATION OF TWO ESTROGENS BY NATURAL DISSOLVED ORGANIC MATTER UNDER SIMULATED SUNLIGHT

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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

Changements de pratiques dans les produits cosmétiques des lanceurs d'alerte aux impacts sur le milieu aquatique

International audiencePrésentation du projet Cosmet'ea

Photodegradation of estrone enhanced by dissolved organic matter under simulated sunlight.

International audienceIn the present work the degradation of estrone (E1) a natural estrogenic hormone has been studied under simulated solar irradiation. The photodegradation of E1 has been investigated in the absence and in the presence of 7.7-8.9 mg L(-1) of dissolved organic carbon (DOC), under solar light simulation with irradiance approximating that of the sun. DOC extracts from different origins have been used. Half-lives ranging between 3.9 h and 7.9 h were observed. Results indicated that E1 was photodegraded even in the absence of DOC. The presence of DOC was found to enhance the degradation of E1. Experiments performed with the addition of reactive species scavengers (azide ions and 2-propanol) have shown that these two species play a significant role in the photodegradation. Some experiments have been performed with a DOC previously submitted to solar irradiation. Changes in optical and physico-chemical properties of DOC strongly affect its photoinductive properties, and hence its efficiency on E1 degradation. A part of the study consisted in the investigation of photoproducts structures. Five photoproducts were shown by chromatographic analysis: one arising from direct photolysis and the four others from DOC photoinduced degradation

Determination of 18 Biocides in Both the Dissolved and Particulate Fractions of Urban and Surface Waters by HPLC-MS/MS

International audienceA robust method is provided to analyze 18 hydrophilic and hydrophobic biocides in both dissolved and particulate fractions of five types of urban and surface waters using high-performance liquid chromatography coupled to tandem mass spectrometry. The linearity, accuracy, and intermediate precision were validated. The target biocides were enriched by solid-phase extraction using Chromabond HR-X 200-mg cartridges and eluted with methanol, ethyl acetate, and dichloro-methane. Suspended matter was extracted by microwave-assisted extraction in methanol and dichlo-romethane. Recoveries and variability (respectively > 75% and < 30% for most of the target biocides and matrices) made it possible to quantify biocides at a trace level in all matrices. Limits of quantification were in the range of nanograms per liter in the dissolved fraction and in the range of nanograms per gram of dry weight in the particulate fraction for most of the biocides and matrices, and were generally lower than those reported in previous studies. The method was successfully applied to surface waters, treated and untreated wastewa-ter, combined sewer overflows, and stormwater, providing unique data in these matrices for some substances , in particular with respect to particle contamination. In urban waters, concentrations of most of the biocides ranged from 10 to 200 ng/L. Diuron, isothiazolinone, and benzalkonium concentrations could reach 0.9, 0.9, and 20 μg/L respectively. In rivers, most of the biocides were measured at less than 10 ng/L, but higher concentrations were observed for benzalkoniums (up to 200 ng/L) or after rain events, which indicates biocide transfer from urban surfaces into the aquatic environment during wet weather

Spatio-temporal variation of the chemical quality and the interactions between organic matter and organic micropollutants in an urban lake

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