College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
J Environ Sci (China). 2012;24(11):1985-94. doi: 10.1016/s1001-0742(11)61036-x.
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 Al were found to be strong competitors for trace metals to EDDS at low application dose and low pH condition.
由于不受控制的电子废物回收活动导致的环境污染在世界范围内引起了越来越多的关注。本研究中，用可生物降解的螯合剂[S，S]-乙二胺二琥珀酸（EDDS）提取这些金属，并研究了影响提取效果的因素。结果表明，在低 pH（5.5）条件下添加 EDDS 比在高 pH（8.0）溶液中提取的金属更多。金属形态分析表明，Cu 在不同 pH 条件下与 EDDS 完全配位，并且使用了不同量的 EDDS。对于 Pb 和 Zn，在低 EDDS 剂量（0.304 mol/kg 土壤）下，它们分别以 Pb-和 Zn-EDDS 的形式存在。但是，在高 EDDS 剂量（1.26 mol/kg 土壤）下，大部分 Pb 与溶解的有机物结合。在低用量和低 pH 条件下，Ca 和 Al 被发现是与 EDDS 竞争痕量金属的强竞争者。
