Evaluation of enhanced soil washing process and phytoremediation with maize oil,carboxymethyl-β-cycl

• 作 者: 叶茂
• 机 构: 南京土壤所
• 出 处: 中国土壤学会土壤环境专业委员会第十七次会议暨2014年土壤环境保护与生态文明建设国际研讨会
• 发表日期: 2014年6期

　　An innovative ex situ soil washing technology was developed in this study to remediate organochlorine pesticides(OCPs)and heavy metals in a mixed contaminated site.Elevated temperature(60 ℃)combined with ultrasonication(40 kHz,20 min)at 50 mL L-1 maize oil and 45 g L-1carboxylmethyl-β-cyclodextrin were effective in extracting pollutants from the soil.After two successive washing cycles,the removal efficiency rates for total OCPs,mirex,endosulfans,chlordanes,Cd,and Pb were approximately 94.7%,87.2%,98.5%,92.3%,91.6%,and 87.3%,respectively.Cultivation of vetiver grass and addition of nutrients for 3 months further degraded 34.7%of the residual total OCPs and partially restored the microbiological functions of the soil.This result was indicated by the significant increase in the number,biomass C,N,and functioning diversity of soil microorganisms(p < 0.05).After the treatment,the residual OCPs and heavy metals existed as very slowly desorbing fraction and residual fraction,as evaluated by Tenax extraction combined with a fast-three-compartment model and sequential extraction.Moreover,the secondary environmental risk of residual pollutants in the remediated soil was at an accept able level.The proposed combined cleanup strategy proved to be effective and environmentally friendly.