In this study, we carried out several sets of laboratory-based experimentsunder various conditions in order to develop technically feasible and cost effective ex-situsediment remediation techniques. The sediment for this study was collected from asewage sludge contaminated site in western Xiamen Bay, China, in July 2005. The mainfindings from this study include (1) low pH condition (pH < 5) and large solid-to-liquidratio (e.g., 1:50) increase metal extraction efficiency by EDTA-2Na, although theefficiency for each metal are different due to chemical properties of each metal andEDTA-2Na; (2) 0.20 M (NH_4)2C_2O_4 + 0.025 M EDTA combination with solid:liquidratio = 1:50 and 0.50 M NH_4Ac + 0.025 M EDTA combination with solid:liquid ratio =1:50 are the adoptable methods to extract metal contaminants with respect to extractionefficiency and economical cost; (3) using 0.010M SDS solution with solid:liquid ratio =1:20 should be avoided because it is much less effective in removal of metals fromsediments; (4) using 0.20 M H2_C_2O_4 solution under aeration with solid:liquid ratio = 1:50yields the best extraction efficiency for Cu (93%), Zn (89%), Cd (79%), Cr (45%) and Ni(66%). But, this method has very low extraction efficiency for Pb (3.4%); and (5) using0.025 M EDTA solution with aeration and solid:liquid ratio = 1:50 has ～73% extractionefficiency for Pb besides moderate to high extraction efficiencies for other metals (exceptfor Cr) ranging from 37% (Ni) to 94% (Cu). This study provides important and usefulinformation for sediment decontamination technology development.
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