Extraction of heavy metals from e-waste contaminated soils using EDDS
Renxiu Yang , Chunling Luo , Gan Zhang , Xiangdong Li , Zhenguo Shen
DOI:10.1016/S1001-0742(11)61036-X
Received January 14, 2012,Revised February 27, 2012, Accepted , Available online November 06, 2012
Volume 24,2012,Pages 1985-1994
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.
