title: Speciation of copper in sewage effluents and its toxicity to Daphnia magna.
abstract: Copper complexation capacity was determined in a range of sewage treatment works final effluents and receiving waters, upstream and downstream of the discharge point. Forty-eight-hour immobilization tests on Daphnia magna were used to assess the toxicity of copper in the effluent matrix. Complexation capacities in effluents were typically in the range 50 to 100 microg Cu/L, with higher values being found in the poorer-quality effluents with higher dissolved organic carbon (DOC) concentrations. The tolerance of Daphnia to dissolved copper concentrations was more than quadrupled in a 50% effluent matrix, with the increase in tolerance being related to complexation capacity. Ligand concentrations in effluents were found to correlate strongly with effluent DOC. No such relationship was observed in surface waters. On mixing with river water, sewage-derived ligands behaved conservatively and were relatively stable over time scales of up to 10 d.
authors.affiliation: Imperial College of Science, Technology and Medicine, Ascot, Berkshire, United Kingdom.
authors.forename: Eleanor
authors.initials: E
authors.lastname: van Veen
authors.forename: Nicola
authors.initials: N
authors.lastname: Burton
authors.forename: Sean
authors.initials: S
authors.lastname: Comber
authors.forename: Michael
authors.initials: M
authors.lastname: Gardner
mesh_terms: D000818:Animals; D003300:Copper / Q000737:chemistry* / Q000633:toxicity*; D003621:Daphnia; D008024:Ligands; D009068:Movement; D012037:Refuse Disposal; D012722:Sewage / Q000737:chemistry*; D012995:Solubility; D014873:Water Pollutants / Q000633:toxicity*
chemical_list: D008024:Ligands; D012722:Sewage; D014873:Water Pollutants; D003300:Copper