污染土壤－芦竹－水体系中As，Cd，Pb和Zn的渗漏与迁移特征
摘要
Leaching trials for metals-contaminated soils were designed for the long-term ecoremediation field plot in the vicinity of smelting areas in Hunan Province. pH, dissolved organic carbon (DOC) and concentrations of metals, such as As, Cd, Pb and Zn in leachants from the different depth soil profiles in contaminated soil-giant reed (Arundo donax L.)-water systems, were investigated through continuous sampling. The results show that concentrations of DOC in leachants from the remediation systems are significantly increased while concentrations of As and Pb in leachants are significantly decreased compared to those from the control systems. Concentrations of Cd and Zn in topsoil layer (0-25 cm) leachants from the remediation systems, however, are slightly decreased. Concentrations of As, Cd and Zn in leachants from the remediation systems are less than the Grade Ⅲ of the Quality Standard for Groundwater (GB/T 14848-93), while those of Pb in leachants just meet the Grade Ⅴ. The annual biomass of aerial part of giant reed is about 4.5 kg/m^2 and it can accumulate 0.03, 0.04, 0.21, 0.17 g/m^2 of As, Cd, Pb and Zn, respectively. It is useful for stabilization and cleanup of As, Cd, Pb and Zn in metals-contaminated soils using giant reed.