THE FLUMINESE MINING DISTRICT (SW SARDINIA, ITALY): IMPACT OF THE PAST LEAD-ZINC EXPLOITATION ON AQUATIC ENVIRONMENT

摘要

A hydrogeochemical survey was carried out in the Fluminese district (SW Sardinia, Italy) to investigate the impact of past mining activities on the aquatic system. Waters in the Fluminese are near-neutral to slightly alkaline. Mine drainages had the highest SO_4 (640 mg/L), Zn (40 mg/L) and Cd (97 mu g/L); other metals show a wide range in concentrations depending on dominant mineral assemblages at each mine. Dissolved Pb in mine waters is in the range of 1 to 53 mu g/L but Pb > 10 mu g/L also occurs in spring and well waters. The metal load discharged daily into the sea under low-flow condition is estimated at about 2160 g for Zn, 21 g for Cd and 30 g for Pb.