不同洗脱剂对污染场地土中多氯联苯洗脱效果的研究

目的]为运用表面活性剂快速、有效地洗脱修复多氯联苯污染场地土壤提供理论依据。方法]以宁波市某变压器垃圾填埋场的PCBs污染场地土壤为研究对象，选用3种非离子表面活性剂（Brij58、Brij30和Tween-80）以及2-羟丙基-β-环糊精作为洗脱剂，进行实验室批量洗脱试验，研究洗脱剂类型、洗脱剂浓度、温度、pH和洗脱次数对PCBs洗脱效率的影响。结果J在4种洗脱剂中，B州58的洗脱效果最好。在温度为25℃、pH为4．5的条件下，10g/L Brij58对污染土壤中多氯联苯的洗脱效率最高，洗脱1次后的2-Cl、3-Cl、4-Cl和5-Cl取代的PCBs洗脱率分别为53％、52％、55％和83％。结论]非离子表面活性剂B川58能够高效洗脱污染场地土壤中的PCBs。

Effect of different Elution Solvents on Eluting PCBs from Contaminated Site Soil

Objective ] The purpose was to provide scientific basis for quick and effective remediation of highly PCB-contaminated site soil by using the approach of surfactant enhanced soil washing. Method] Batch experiments were performed to investigate effects of three nonionic surfactants （ Brij58, Brij30 and Tween-80） and 2-hydroxypropyl-beta-cyclodextrin on solubilization and elution of PCBs from transformer land- fill contaminated soils collected from Ningbo. The effect of concentrations of elution solvent, temperature, pH and elution times on the washing efficiencies of PCBs was also determined. Conclusion] Brij58 was the most effective eluant among four elution solvents in washing PCBs from contaminated soil. Elution efficiencies of 2-C1, 3-C1, 4-C1 and 5-C1 substituted PCBs are 53%, 52%, 55% and 80%, respectively, when contaminated soil was extracted by Brij58 at 10 g/L, 25℃ and pH 4.5 after one time elution. Conclusion] Brij58 could highly active to e- lute PCBs from contaminated site soil.