[Feasibility of washing as a remediation technology for the heavy metals-polluted soils left by chemical plant].
Laboratory simulation tests were conducted to examine the effects of different washing reagents (distilled water, HCl, H3PO4, oxalic acid, and CaCl2) in extracting the heavy metals from contaminated soils left by a chemical plant. The effects of reagent concentration, reaction time, and washing time on the washing efficiency were investigated, and the form variation of test heavy metals was determined before and after HCl washing. Distilled water, H3PO4, and CaCl2 could remove less than 1% of most heavy metals, and the highest removal rate was only 3.58%; while 2 mol HCl x L(-1) could obtain the highest washing efficiency under the optimal conditions, i. e., soil:liquid ratio was 1:3, reaction time was 1 hour, and the soils were washed twice by HCl solution. The removal rates of Cr, Pb, Zn, Cu, and Cd from test soils were 80.75%, 88.69%, 98.00%, 79.33%, and 95.52%, respectively. Among the washing reagents, HCl could effectively remove all forms of heavy metals.
Liu
Lei
L
Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029, China. panda301@zju.edu.cn
Hu
Shao-Ping
SP
Chen
Ying-Xu
YX
Li
Hang
H
D002617:Chemical Industry; D003666:Decontamination / Q000379:methods* / Q000706:statistics & numerical data; D005240:Feasibility Studies; D006851:Hydrochloric Acid / Q000737:chemistry*; D007220:Industrial Waste; D019216:Metals, Heavy / Q000032:analysis / Q000302:isolation & purification*; D012989:Soil Pollutants / Q000032:analysis / Q000302:isolation & purification*
D007220:Industrial Waste; D019216:Metals, Heavy; D012989:Soil Pollutants; D006851:Hydrochloric Acid