Régis Moilleron

Priority pollutants in wastewater and combined sewer overflow.

Implementation of the European Water Framework Directive and its affiliated directives requires Member States to improve their understanding of priority pollutants (PPs) in urban areas and obviously within wastewater systems. As a direct consequence, this study is intended to furnish data on both PP occurrence and the significance of concentrations in wastewater during dry and wet periods within combined sewers. Various sampling sites within the Paris combined sewer network were selected; for each sample, a total of 66 determinants, including metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, organotins, volatile organic compounds, chlorobenzenes, phthalates and alkylphenols, were analysed. A broad range of PPs was observed in wastewater during dry as well as wet weather periods. Of the 66 elements investigated, 33 and 40 priority substances could be observed in raw sewage and wet weather effluent, respectively. As expected, a majority of metals were present in all samples, reflecting their ubiquitous nature. For both periods, chlorobenzenes and most of the pesticides always remained below the limit of quantification, while the majority of other organic pollutants assessed were identified within the microg l(-1) range. As highlighted by the larger number of substances detected in wet weather samples and the significance of their concentrations, runoff via atmospheric inputs and/or surface leaching was found to induce a wider range of PPs (n=40) and lead to higher concentrations of certain metals, PAHs, pesticides and other individual compounds. The data generated during this survey, which constitutes one of the first studies conducted in Europe to report concentrations for a variety of priority substances in wastewater within combined sewers, may be used in the future to identify PPs of potential significance for dry and wet weather periods and targeted for further investigation.

Priority pollutants in urban stormwater: Part 1 – Case of separate storm sewers

Organic and mineral pollutants have become part of todays urban environment. During a rain event, stormwater quality as well as the corresponding contaminant loads is affected by both atmospheric deposition and the various types of impervious surfaces (roads, rooftops, parking lots etc.) on which runoff occurs. This study provides results on stormwater pollution in Paris and its suburbs from three separate storm sewers (n=20 samples). These results show that the stormwater had been contaminated by 55 chemical substances out of the 88 investigated. A particular attention was given to stormwater particle contamination. Concentrations are provided for: metals, PAHs, PCBs, organotins, alkylphenols, phthalates, pesticides, and VOCs. Our findings are among the first available in the literature since the relevant analyses were all conducted on both the particulate (P) and dissolved (D) phases. For most substances, particles from the three storm sewers were more heavily contaminated than dredged sediments and settleable particles from the Seine River. As a consequence of this finding, the release of untreated stormwater discharges may impact the receiving waters and contribute to sediment contamination.

Partition of pollution between dissolved and particulate phases: what about emerging substances in urban stormwater catchments?

This paper presents results about the occurrence, the concentrations of urban priority substances on both the dissolved and the particulate phases in stormwater. Samples were collected at the outlet of a dense urban catchment in Paris suburb (2.30 km(2)). 13 chemical groups were investigated including 88 individual substances. Results showed that stormwater discharges contained 45 substances among them some metals, organotins, PAHs, PCBs, alkylphenols, pesticides, phthalates, cholorophenols and one volatile organic compound, i.e. methylene chloride. With respect to the European Water Framework Directive, these substances included 47% of the priority hazardous substances (n = 8), 38% of the priority substances (n = 10). The remaining substances (n = 27) belong to a list of others specific urban substances not included in the Water Framework Directive but monitored during this work. Finally, stormwater quality was evaluated by comparing the substance concentrations to environmental quality standards (EQS) and the particulate content to Canadian sediment quality guidelines. This showed that stormwater was highly contaminated and should be treated before being discharged to receiving waters in order to avoid any adverse impact on the river quality.

Hydrocarbons and Metals in Atmospheric Deposition and Roof Runoff in Central Paris

Hydrocarbons (aliphatic and aromatic) and metals (heavy metals and major elements) were measured in both atmospheric deposition and roof runoff in central Paris (France). Atmospheric deposition (wet and dry) was collected from December 2001 to October 2002 and roof runoff was sampled on three buildings with different covering materials, i.e., slate tiles and zinc sheets. This paper gives an overview of the results on the flux and distribution points of view for both atmospheric deposition and roof runoff. Results show that atmospheric fluxes of hydrocarbons and major elements increase during cold seasons, due to residential heating occurrence, while heavy metals, whose major sources have constant emission fluxes, exhibit steady atmospheric loads throughout the year. Moreover, hydrocarbon fingerprints reveal mainly biogenic and pyrolytic origins for aliphatic and aromatic hydrocarbons, respectively. The results about roof runoff contamination suggest that the scavenging processes for hydrocarbons and metals are dependent on rainfall amount rather than on the rain event characteristics (number, intensity, duration), and dry deposition weakly contributes to the pollutant loads in roof runoff. Results also highlight that both metallic and slate roofs do not act as a source of hydrocarbons and major elements—exclusively originating from atmospheric deposition—while they act as a source of some heavy metals. Zinc-covered roofs largely release Zn and Ti, while slate roofs mainly release Pb, Ti and Cu. Whatever the material used for roof covering, roof runoff presents high Ni and V loads due to the vicinity of the chimney stacks of heating boilers.

Micropollutants in urban stormwater: occurrence, concentrations, and atmospheric contributions for a wide range of contaminants in three French catchments

This study aimed at: (a) providing information on the occurrence and concentration ranges in urban stormwater for a wide array of pollutants (n = 77); (b) assessing whether despite the differences between various catchments (land use, climatic conditions, etc.), the trends in terms of contamination level are similar; and (c) analyzing the contribution of total atmospheric fallout (TAF) with respect to sources endogenous to this contamination. The studied contaminants include conventional stormwater contaminants (polycyclic aromatic hydrocarbons (PAHs), Zn, Cu, Pb, etc.), in addition to poorly or undocumented pollutants such as nonylphenol and octylphenol ethoxylates (NPnEO and OPnEO), bisphenol A (BPA), polybrominated diphenyl ethers (PBDEs), a wide variety of pesticides, and various metals of relevance (As, Ti, Sr, V). Sampling and analysis were performed using homogeneous methods on three urban catchments with different land use patterns located in three distinct French towns. For many of these pollutants, the results do not allow highlighting a significant difference in stormwater quality at the scale of the three urban catchments considered. Significant differences were, however, observed for several metals (As, Cr, Cu, Ni, Sr and Zn), PAHs, and PBDEs, though this assessment would need to be confirmed by further experiments. The pollutant distributions between dissolved and particulate phases were found to be similar across the three experimental sites, thus suggesting no site dependence. Lastly, the contributions of TAF to stormwater contamination for micropollutants were quite low. This finding held true not only for PAHs, as previously demonstrated in the literature, but also for a broader range of molecules such as BPA, NPnEO, OPnEO, and PBDEs, whose high local production is correlated with the leaching of urban surfaces, buildings, and vehicles.

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

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 1 μgl(-1), while metals tend to display concentrations above 10 μgl(-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.

Priority pollutants in surface waters and settleable particles within a densely urbanised area: Case study of Paris (France)

Implementation of the European Water Framework Directive 2000/60/EC (WFD) requires Member States to expand their collective knowledge of priority pollutants (PPs) within receiving waters. To achieve this objective, information on the occurrence of PPs in surface waters and, more specifically, within densely urbanized areas needs to be collected. This study has therefore been designed to provide information on both PP occurrence and concentration build-up along a heavily urbanized transect of the Seine River in the Paris region (France). A large range of PPs were observed in settleable particles and, to a lesser extent, in the waters surveyed. In surface waters, a total of 18 PPs, including 15 priority hazardous substances, were indeed detected, yet concentrations rarely exceeded the limit of quantification. In fact, only diuron, DEHP, fluoranthene and para-tert-octylphenol are observed on a frequent basis, with concentrations ranging from <0.01 to 1.0 microg l(-1). As regards the Environmental Quality Standards (EQS), 10 substances or groups of substances were found in surface waters to exhibit concentrations above the annual average value, while only the benzo(a)pyrene concentration exceed the maximum allowable level. As for the Canadian Sediment Quality Guidelines, settleable particles collected in the Seine River appear to be heavily contaminated since most samples contain PP levels above the guideline values (18 PPs) and, in many cases, above the probable effect levels (15 PPs), which underscores that the levels of metals, PAHs and PCBs in settleable particles constitute a potential risk to freshwater organisms.

Meta-analysis of environmental contamination by phthalates

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. Many studies have reported the occurrence of phthalates in different environmental matrices; however, none of these studies has yet established 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), we reviewed data 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. 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.

Comparison of Culture Methods for Isolation of Nontuberculous Mycobacteria from Surface Waters

ABSTRACT The environment is the likely source of most nontuberculous mycobacteria (NTM) involved in human infections, especially pulmonary, skin, and soft tissue infections. In order to measure the prevalence of NTM in different aquatic ecosystems, we tried to standardize the culture methods used for surface water testing since many procedures have been described previously. Cultivation of mycobacteria requires long-term incubation in rich media and inactivation of rapidly growing microorganisms whose growth impedes observation of mycobacterial colonies. Consequently, the two criteria used for evaluation of the methods examined were (i) the rate of inhibition of nontarget microorganisms and (ii) the efficiency of recovery of mycobacteria. We compared the competitive growth of Mycobacterium chelonae and M. avium with nontarget microorganisms on rich Middlebrook 7H11-mycobactin medium after treatment by several chemical decontamination methods that included acids, bases, detergent, or cetylpyridinium chloride (CPC) with and without an antibiotic cocktail, either PANTA (40 U/ml polymyxin, 4 μg/ml amphotericin B, 16 μg/ml nalidixic acid, 4 μg/ml trimethoprim, and 4 μg/ml azlocillin) or PANTAV (PANTA plus 10 μg/ml vancomycin). Our results showed that treatment for 30 min with CPC (final concentration, 0.05%) of water concentrated by centrifugation, followed by culture on a rich medium supplemented with PANTA, significantly decreased the growth of nontarget microorganisms (the concentrations were 6.2 ± 0.4 log10 CFU/liter on Middlebrook 7H11j medium and 4.2 ± 0.2 log10 CFU/liter on Middlebrook 7H11j medium containing PANTA [P < 0.001]), while the effect of this procedure on NTM was not as great (the concentrations of M. chelonae on the two media were 7.0 ± 0.0 log10 CFU/liter and 6.9 ± 0.0 log10 CFU/liter, respectively, and the concentrations of M. avium were 9.1 ± 0.0 log10 CFU/liter and 8.9 ± 0.0 log10 CFU/liter, respectively). We propose that this standardized culture procedure could be used for detection of NTM in aquatic samples.

Removal of a wide range of emerging pollutants from wastewater treatment plant discharges by micro-grain activated carbon in fluidized bed as tertiary treatment at large pilot scale

Among the solutions to reduce micropollutant discharges into the aquatic environment, activated carbon adsorption is a promising technique and a large scale pilot has been tested at the Seine Centre (240,000 m(3)/d - Paris, France) wastewater treatment plant (WWTP). While most of available works studied fixed bed or contact reactors with a separated separation step, this study assesses a new type of tertiary treatment based on a fluidized bed containing a high mass of activated carbon, continuously renewed. For the first time in the literature, micro-grain activated carbon (μGAC) was studied. The aims were (1) to determine the performances of fluidized bed operating with μCAG on both emerging micropollutants and conventional wastewater quality parameters, and (2) to compare its efficiency and applicability to wastewater to former results obtained with PAC. Thus, conventional wastewater quality parameters (n=11), pharmaceuticals and hormones (PPHs; n=62) and other emerging pollutants (n=57) have been monitored in μGAC configuration during 13 campaigns. A significant correlation has been established between dissolved organic carbon (DOC), PPHs and UV absorbance at 254 nm (UV-254) removals. This confirms that UV-254 could be used as a tertiary treatment performance indicator to monitor the process. This parameter allowed identifying that the removals of UV-254 and DOC reach a plateau from a μGAC retention time (SRT) of 90-100 days. The μGAC configuration substantially improves the overall quality of the WWTP discharges by reducing biological (38-45%) and chemical oxygen demands (21-48%), DOC (13-44%) and UV-254 (22-48%). In addition, total suspended solids (TSS) are retained by the μGAC bed and a biological activity (nitratation) leads to a total elimination of NO2(-). For micropollutants, PPHs have a good affinity for μGAC and high (>60%) or very high (>80%) removals are observed for most of the quantified compounds (n=22/32), i.e. atenolol (92-97%), carbamazepine (80-94%), ciprofloxacin (75-95%), diclofenac (71-97%), oxazepam (74-91%) or sulfamethoxazole (56-83%). In addition, alkylphenols, artificial sweeteners, benzotriazole, bisphenol A, personal care products (triclocarban and parabens) and pesticides have removals lying in the 50 ->90% range. Overall, the fluidized bed of μGAC allows obtaining performances comparable to PAC at the same activated carbon dose. Indeed, the average removal of the 13 PPHs found at a high occurrence (>75%) in WWTP discharges is similar at 20 g/m(3) of μGAC (78-89%) and PAC (85-93%). In addition, this recycled μGAC operation leads to several operational advantages (no FeCl3, reactivable, higher SRT, higher treated flow) and has a stronger impact on the overall wastewater quality compared to PAC.