Environmental contamination due to uncontrolled e-waste recycling activities is drawing increasing attention in the world. Extraction of these metals with biodegradable chelant [S,S]-ethylenediaminedisuccinic acid （E...Environmental contamination due to uncontrolled e-waste recycling activities is drawing increasing attention in the world. Extraction of these metals with biodegradable chelant [S,S]-ethylenediaminedisuccinic acid （EDDS） and the factors influencing extraction efficacy were investigated in the present study. Results showed that the addition of EDDS at low pH （5.5） produced higher metal extraction than that at high pH （8.0） solution. Metal speciation analysis indicated that Cu was completely complexed with EDDS at different pH conditions with various amounts of EDDS applied. For Pb and Zn, at low EDDS dose of 0.304 mol/kg soil, they were present as Pb- and Zn-EDDS. However, at high EDDS dose of 1.26 mol/kg soil, most of Pb was bound with dissolved organic matter. Ca and A1 were found to be strong competitors for trace metals to EDDS at low application dose and low pH condition.展开更多
基金supported by the Research Grants Council of the Hong Kong SAR Government (No.PolyU5212/08E)the Natural Science Foundation of Jiangsu Province (No.BK2010064)+1 种基金the Social Development Foundation of Jiangsu Province (No.BE2011781)Joint Funds of the National Natural Science Foundation of China and the Natural Science Foundation of Guangdong Province, China (No.NSFC-GDNSF, U1133004)
文摘Environmental contamination due to uncontrolled e-waste recycling activities is drawing increasing attention in the world. Extraction of these metals with biodegradable chelant [S,S]-ethylenediaminedisuccinic acid （EDDS） and the factors influencing extraction efficacy were investigated in the present study. Results showed that the addition of EDDS at low pH （5.5） produced higher metal extraction than that at high pH （8.0） solution. Metal speciation analysis indicated that Cu was completely complexed with EDDS at different pH conditions with various amounts of EDDS applied. For Pb and Zn, at low EDDS dose of 0.304 mol/kg soil, they were present as Pb- and Zn-EDDS. However, at high EDDS dose of 1.26 mol/kg soil, most of Pb was bound with dissolved organic matter. Ca and A1 were found to be strong competitors for trace metals to EDDS at low application dose and low pH condition.
