Are percolates released from solid waste incineration bottom ashes safe for lentic ecosystems? A laboratory ecotoxicological approach based on 100 litreindoor microcosms

• Published in: Aquatic ecosystem health & management Vol. 8; no. 4; pp. 427 - 439
• Main Authors: Clement, B, Triffault-Bouchet, G, Lottmann, A, Carbonel, J
• Format: Journal Article
• Language: English
• Published: 01.01.2005
• Subjects: Ceriodaphnia dubia; Cladocera; Daphnia magna; Hyalella azteca; Lymnaea stagnalis; Physa; Simocephalus vetulus; France
• ISSN: 1463-4988
• DOI: 10.1080/14634980500354954

In France, municipal solid waste incineration bottom ashes are widely used in road building. Leachates released from these materials may constitute a hazard for aquatic ecosystems. In order to assess this risk, a study of bottom ash leachates toxicity was carried out on 100 litre indoor microcosms. The 100 litre microcosms are glass tanks filled with a lake sediment and synthetic water, and inoculated with various organisms: microalgae, duckweeds, rooted macrophytes, cladocerans, pond snails, amphipods and chironomids. The microcosms were contaminated twice so as to reach a final leachate concentration of three percent The contamination led to increased salt and metal concentrations. Among cladocerans, Daphnia magna was sensitive to contamination although recovery was observed, whereas Simocephalus vetulus and Ceriodaphnia dubia were not. Results regarding the amphipod Hyalella azteca depended on major exposure, via the water column (encaged organisms) or via the sediment (free organisms). Chironomids emerged similarly in control and contaminated systems. Among pond snails, leachates impaired survival and grazing activity of Lymnaea stagnalis, whereas Physa sp. was not sensitive. Growth of all primary producers tested in the microcosms was not impaired. Copper may explain most of the observed effects. Due to the fact that concentrations studied here seem to be an overestimation of real field concentrations, and that bottom ash leachates characteristics decrease with time, it was concluded that the risks for lentic aquatic ecosystems would be minimal.