Extraction of Heavy Metals in Loamy Soils by Biodegradable S,S-ethylene Diamine Disuccinic Acid and Ethyl Lactate

摘要

Organic ligands are often considered as agents to extract metals from soils during the remediation of metal-contaminated soils. In this study, biodegradable organic ligand [S,S] stereoisomer of ethylene diamine disuccinate (EDDS) and ethyl lactate were investigated for extracting heavy metals from loamy soils near mine facility using batch experiments. Soil samples were analyzed by X-ray diffraction (XRD) before and after the extraction. Results showed that EDDS possessed a higher extraction efficiency for Cd, Cu, Pb and Zn than ethyl lactate. Compared to EDDS alone, combining EDDS and ethyl lactate in extraction did not demonstrate significant enhancement in extraction efficiency. Although pH had some influence on the extraction efficiency for metals, it was probably not the key factor in studied pH range. XRD analysis of the extracted soil residues, however, suggested that the extraction had influenced soil structures.