Metal availability in a highly contaminated, dredged-sediment disposal site: field measurements and geochemical modeling.
Two complementary approaches were used to characterize arsenic and metal mobilizations from a dredged-sediment disposal site: a detailed field study combined with hydrogeochemical modeling. Contaminants in sediments were found to be mainly present as sulfides subject to oxidation. Secondary phases (carbonates, sulfates, (hydr)oxides) were also observed. Oxidative processes occurred at different rates depending on physicochemical conditions and contaminant contents in the sediment. Two distinct areas were identified on the site, each corresponding to a specific contaminant mobility behavior. In a reducing area, Fe and As were highly soluble and illustrated anoxic behavior. In well-oxygenated material, groundwater was highly contaminated in Zn, Cd and Pb. A third zone in which sediments and groundwater were less contaminated was also characterized. This study enabled us to prioritize remediation work, which should aim to limit infiltration and long-term environmental impact.
Lions
Julie
J
BRGM, 3 Avenue Claude Guillemin, 45060 Orléans Cedex 2, France. j.lions@brgm.fr
Guérin
Valérie
V
Bataillard
Philippe
P
van der Lee
Jan
J
Laboudigue
Agnès
A
D001151:Arsenic / Q000032:analysis; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D055593:Geological Phenomena; D008670:Metals / Q000032:analysis*; D008956:Models, Chemical; D012037:Refuse Disposal; D014874:Water Pollutants, Chemical / Q000032:analysis*
D008670:Metals; D014874:Water Pollutants, Chemical; D001151:Arsenic