Assessment of Soil Acid Washing Technique for Multiple Metals Contaminated Soil in an Industrial Site of North Taiwan
The feasibility of soil acid washing technique for the remediation of heavy metal COntaminated soils from aIl industrial site was assessed by this research.Five sandy soil samples with high pH(8~10)COllected from the site were seriously COntaminated withCu(max.1620mg/kg)，Zn(max.9880 mg/kg)，Cr(max.697 mg/kg)， Ni(max.510 mg/kg)，and Pb(max.822 mg/kg).Apreliminary study Was COnducted to find the ideal parameter Of Soil acid washing technique specific for the COntaminated soils.Hydrochloric acid and phosphodc acid wcrc used as extracting agents under different COncentrations(0.1M，0.5M，and IM)，soil-to-acid ratios(1:3 and 1:5)， and stirring time(5 to 30 min).The best parameter is using 0.5 M HCl under the soil·to-acid ratio of 1:3 and stiirring for 30 minutes.Ten minutes Were needed to settle down most soil particles by gravity.After washing the COntaminated soils two times.the removal rates of metals from COntaminated soils in average was 40％ for Cu, 60％ for Zn，20％ for Ni，and 60％ for Pb，respectively.Thethird time washing has no apparent enhanCOment for the heavy metal removal rates.The soil acid washing technique used in this study cannot reduce all the heavy metal COncentration in the soil down to the‘Soil Pollution Remediation Standards”announced by Taiwan Environmental protection departments.The pH of washed soil iS very low, so the soil reclamation operations Were required to reCOVer soil functions.The high spatial variation of heavy metal COncentration in the soil of COntaminated site will be a big ehallenge for future practices of soil remediation.
土壤酸洗技术 重金属污染 盐酸 磷酸 去除率 土壤污染
Zueng-Sang Chen Shaw-Wei Su
Department of Agricultural Chemistry,Taiwan University;No．1,Sec．4,Roosevelt Road,Taipei 10617,Taiwan
国内会议
西安
英文
30-32
2008-08-03（万方平台首次上网日期，不代表论文的发表时间）