Title: Removal of Cd, Pb, Cu and Zn from real contaminated soils with fresh and regenerated Na₂EDTA

Authors: Ming Lei; Min Zeng; Pu-feng Qin; Bo-han Liao; Bai-qing Tie; Mikiya Tanaka

Addresses: College of Resource and Environment, Hunan Agricultural University, Changsha, Hunan 410128, China. ' College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China. ' College of Resource and Environment, Hunan Agricultural University, Changsha, Hunan 410128, China. ' College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China. ' College of Resource and Environment, Hunan Agricultural University, Changsha, Hunan 410128, China. ' National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8569, Japan

Abstract: The leaching efficiencies using both fresh Na₂EDTA and regenerated Na₂EDTA on the remediation of contaminated soils from Chenzhou lead-zinc mining area located in southern Hunan Province (southern China) were investigated. The total concentrations of Cd, Pb, Cu and Zn in both contaminated soils exceeded the maximum permissible limits set by Ministry of Environmental Protection for soil. Under the optimum conditions, 35% for Cd, 64% for Pb, 25% for Cu and 14% for Zn from garden soil and 97% for Cd, 87% for Pb, 46% for Cu and 33% for Zn from paddy soil were leached with 0.05M Na₂EDTA. Removal of Cd, Pb, Cu and Zn from leaching solution containing EDTA increased with increasing Na₂S addition, while about 0.15M Na₂S solution was used to separate all metals from metal-EDTA solution. Through three times regeneration and reuse, the regenerated Na2EDTA solutions have leaching ability of Cd, Pb, Cu and Zn from both contaminated soil.

Keywords: disodium ethylenediamine-tetraacedtic acid; Na2EDTA; heavy metals; contaminated soil; sodium sulphide; regeneration; environmental pollution; leaching efficiency; China; soil remediation; cadmium; lead; copper; zinc.

DOI: 10.1504/IJETM.2012.045145

International Journal of Environmental Technology and Management, 2012 Vol.15 No.1, pp.50 - 60

Received: 23 Jul 2010
Accepted: 25 Mar 2011
Published online: 17 Dec 2014 *

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