Influence of effluent organic matter on copper speciation and bioavailability in rivers under strong urban pressure

• Published in: Environmental science and pollution research international Vol. 22; no. 24; pp. 19461 - 19472
• Main Authors: Matar, Z., Soares Pereira, C., Chebbo, G., Uher, E., Troupel, M., Boudahmane, L., Saad, M., Gourlay-France, C., Rocher, V., Varrault, Gilles
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2015; Springer Nature B.V; Springer Verlag
• Subjects: Absorbance; Affinity; Aquatic environment; Aquatic plants; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Binding sites; Bioavailability; Carbon; Copper; Copper - analysis; Dissolved organic carbon; Dissolved organic matter; Downstream; Earth and Environmental Science; Earth Sciences; Ecotoxicology; Effluents; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Environmental Sciences; Humans; Hydrology; hydrophilicity; Low flow; Metals; Metals - chemistry; Paris; Receiving waters; Research Article; Rivers; Rivers - chemistry; Sciences of the Universe; spatial variation; Speciation; Surface water; temporal variation; Toxicity; trace elements; Trace metals; Upstream; Waste Water - analysis; Waste Water Technology; Wastewater treatment; Wastewater treatment plants; Water Management; Water Pollutants, Chemical - analysis; Water Pollution Control; Water treatment; Paris; Lebanon; Beirut Lebanon; France; Seine River; Biotic ligand model; Dissolved organic matter; Trace metals; Hydrophilic organic matter; EfDOM; Bioavailability; Speciation; DISSOLVED ORGANIC MATTER; TRACE METALS; EFDOM; HYDROPHILIC ORGANIC MATTER; BIOTIC LIGAND MODEL
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-015-5110-6

This study focuses on spatiotemporal variations in the type of dissolved organic matter (DOM) and copper binding ability both upstream and downstream of Paris. It also compares the relative influence of both natural DOM upstream of Paris and effluent dissolved organic matter (EfDOM) output from a wastewater treatment plant (WWTP) on trace metal speciation and bioavailability in aquatic systems. In addition to the typical high- and low-affinity binding sites, a third family of very high-affinity binding sites has been highlighted for EfDOM. In receiving waters downstream of Paris during low-flow periods, the percentage of high- and very high-affinity sites originating from EfDOM reaches nearly 60 %. According to the speciation computation, the free copper concentration upstream of Paris exceeds the downstream Paris concentration by a factor of 2 to 4. As regards copper bioavailability, the highest EC50 tot values were observed for EfDOM and downstream DOM, with a very low aromaticity and low UV absorbance. This finding suggests that specific ultraviolet absorbance (SUVA) is unlikely to be useful in assessing metal speciation and toxicity in aquatic systems subject to strong urban pressures. These results also highlight that the copper speciation computation for surface water exposed to considerable human pressures should include not only the humic and/or fulvic part of dissolved organic carbon but more hydrophilic fractions as well, originating for example from EfDOM.