Monitoring and treatment of selected nanoparticles.

With their increasing use, nanoparticles will become concentrated in urban effluents in the future. Both adequate monitoring methods and water treatment technologies will be necessary to assess and avoid consumer exposure. This paper reports results in these two challenging areas for both organic and inorganic nanoparticles. Treatment experiments indicate that lamellar settling is better adapted than dissolved air flotation for SiO(2) nanoparticles removal. The use of 120 mg/L of Aqualenc coagulant without flocculant addition allows 99% removal to be achieved for an initial concentration of 1 g/L. On the other hand, the dissolved air flotation process implemented under the usual industrial conditions does not permit removal of SiO(2) nanoparticles. In this case SiO(2) removal occurs only by settling in the flocculator tank. Application of a high resolution liquid chromatography/mass spectrometry (LC/MS) technique to a small selection of treated urban effluents indicates that C(60) fullerenes are not yet widely distributed in effluents; however non-point sources cannot be entirely ruled out.

Development of a common priority list of pharmaceuticals relevant for the water cycle.

Pharmaceutically active compounds (PhACs), including prescription drugs, over-the-counter medications, drugs used in hospitals and veterinary drugs, have been found throughout the water cycle. A desk study was initiated by the Global Water Research Coalition to consolidate a uniform selection of such compounds in order to judge risks of PhACs for the water cycle. By identifying major existing prioritization efforts and evaluating the criteria they use, this study yields a representative and qualitative profile ('umbrella view') of priority pharmaceuticals based on an extensive set of criteria. This can then be used for further studies on analytical methods, occurrence, treatability and potential risks associated with exposure to PhACs in water supply, identifying compounds most likely to be encountered and that may have significant impact on human health. For practical reasons, the present study excludes veterinary drugs. The pragmatic approach adopted provides an efficient tool to manage risks related to pharmaceuticals and provides assistance for selecting compounds for future studies.

Assessment of alkylphenols in wastewater treatment: do we comply with new directives?

The fate of various alkylphenolic compounds during wastewater treatment was studied at full scale in thirteen plants, selected in order to cover a wide range of treatment processes, sizes and countries. In-depth investigations consisted in the analysis of nonylphenols, short chained (n = 1, 2) but also long chained polyethoxylates in raw wastewaters, effluents, raw and treated sludges. The degradation of long chained polyethoxylates (APnEO) was shown, resulting in significant production of alkylphenols that concentrate in the sludges. Results show however that the pending Directive on spreading of sludge on land would be complied with in all cases. For the effluent, the EQS established within the WFD might not be satisfied in very critical situations where the dilution factor of the effluent in the river would be too small.

Analysis of drugs and personal care products in French source and drinking waters: the analytical challenge and examples of application.

This paper illustrates the challenge faced by analytical chemists when trying to measure selected compounds representative of various classes of prescription and hospital drugs. Because hundreds of drugs belonging to a wide variety of chemical groups are allowed for use, an array of analytical methods has to be implemented. As an example, as part of the European Poseidon Project, five different methods were required to measure eight drugs and personal care products. These methods are discussed in detail. Examples of application to surface and ground waters from the Paris area are also reported. The antibiotics roxithromycin and sulfamethoxazole were detected for the first time in the Seine River downstream of Paris. The behaviour of the eight target compounds during aquifer recharge and drinking water treatment is described. An incident involving the detection of micrograms per litre levels of the personal care product Galaxolide in a drinking water distribution system is reported. The value of the pharmaceuticals and personal care products selected as potential indicators is also discussed.