Also since 2004 extensive measurement programs at industrial sites across the territory they have been launched under the aegis of the Ministry of Ecology and Sustainable Development program, which culminated in the publication of a report INERIS and a number of recommendations. However, the search for these micro-scale of a few nanometers is complex and delicate. Where necessary for specific analytical protocols have been developed as part of amps. Launched in 2006, for a period of three years, the Cemagref, Suez Environment and University of Bordeaux 1, with the support of the Water Agency Rhone-Mediterranean and Corsica, AMPERES, co-funded by the ‘Agence Nationale de la Recherche (ANR) aimed to measure concentrations of micropollutants in wastewater treatment in and out of treatment plants and evaluate the disposal capacity of different treatment technologies.

21 stations, 2,000 samples, 5,000 tests

AMPERES integral part of the European Water Framework Directive (WFD) adopted in 2000. Remember that it is intended to ensure the health of aquatic and maintain sustainable and cost all activities and uses of water. So she sets out for any natural aquatic environments “good ecological and chemical status” that must be achieved by 2015. The groundbreaking this particular directive requires the reduction of emissions of 33 substances classified as “priority” in the wild by 2015, which positioned in the leader vis-a-vis its counterparts around the world. Among these 33 substances, 13 must be removed from aquatic environments by 2015, emissions of 20 of them to be reduced under the EU Directive 2008/105 of December 16, 2008. So to anticipate the issues of protection of aquatic environments and biodiversity set by the DCE that the Cemagref and Suez Environment has launched, in 2006, the program AMPERES. “Our objective was to develop methods of sampling and analysis that are appropriate to the study of micropollutants in wastewater and sludge, measured concentrations and fluxes of micropollutants generated by waste treatment plants home, assess the performance of conventional treatment processes in domestic sewage treatment plants but also to identify and evaluate advanced tertiary treatment of the most promising, “summarizes Marina Coquery, director of research at Cemagref and coordinator AMPERES program.

21 treatment plants have been studied during this program, 17 of them using conventional treatments, the remaining 4 stations using advanced treatments. Recall that a sewage plant just come down to a waste water from a treated water that comes out, and sludge production. “So we sought primarily to develop an overall treatment of a wastewater treatment plant including water and sludge. We also took into account the variability over 24 hours since the production of day and night are different, “says she. In all, more than 2,000 samples were taken at entry and exit of WWTP, as well as many intermediate points along the processing line, from which were made 5000 tests over 3 years . These samples were taken during different campaigns, each lasting about two weeks. “Each sampling point has resulted in more than 300 tests over 3 days,” said Marina Coquery recalling that 8 laboratories in France and Europe work together to meet this challenge.

Generally reassuring results

The results just presented show that the treatment plants, designed primarily to treat nitrogen, phosphorus and carbon, in accordance with European regulations, adopt 85% of the substances known as “priority” and 35% of other substances released into the studied wastewater. Among them, substances absorbed, retained in the sludge of the station, as DEHP is a plasticizer, the PBDEs are flame retardants, fluoranthene, an aromatic hydrocarbon, and most metals. Other examples of molecules also removed during the passage of wastewater into the station, biodegradable substances such as aspirin, ibuprofen or paracetamol, but also volatile substances such as dichloromethane, a chemical solvent. In contrast, AMPERES showed that 25% of the detected substances are refractory to biological treatment and that 50% of these substances including detergents, a plasticizer, a chemical solvent or aspirin, are present in treated water because of their high concentration input station despite their efficient elimination. Finally, ten substances of concern have been identified as likely to be exceeded standards when the flow of receiving stream is very very low. It includes an anti-fouling, two detergents, chemical solvents, pesticides and two four aromatic compounds or PAHs.

As part of amps, the efficiency of tertiary processes developed as ozonation, activated carbon filtration or reverse osmosis to remove micropollutants, was also evaluated. The results obtained show that these methods allow complete elimination of the majority, ie over 90% of micropollutants still present in the water output of a conventional treatment plant. “In pushing the tertiary treatment to reverse osmosis and ozonation, the process used in the production of drinking water, would release virtually no impact on the aquatic environment”, said the program coordinator . AMPERES has shown that to achieve effective removal of nearly all micro, it is necessary to establish an advanced tertiary sector.

Meeting the challenge of “good” ecological and chemical

Overall, AMPERES thus provides a reassuring answer to address concerns arising from environmental concerns related to the presence of substances called “priority” and “emerging” in domestic wastewater. However, the growth of environmental concerns and better preservation of aquatic environments may require the implementation of more sophisticated treatments beyond 2015. As for the challenge of “good” ecological and chemical water bodies in France defined by the WFD, the meeting will require an increased effort on the entire watershed. This will require a mastery of non-domestic discharges into the sewerage systems (reduction of micro discharges at source), optimizing the management of stormwater, with urban redevelopment and a generalization of online processing, and finally monitoring Increased aquatic environments, particularly in releases into the environment.

Source:http://www.bulletins-electroniques.com/actualites/62687.htm