Tween 80对DDTs污染场地土壤的增溶洗脱效果研究  

Effect of Nonionic Surfactant Tween 80 on Enhanced Solubilization of DDTs from Contaminated Site Soil

作　　者：陈伟伟[1,2,3] 王国庆[2,3] 章瑞英[1,2,3] 赵欣[2,3] 林玉锁[2,3] 

机构地区：[1]南京农业大学资源与环境科学学院,南京210095 [2]环境保护部南京环境科学研究所,南京210042 [3]国家环境保护土壤环境管理与污染控制重点实验室,南京210042

出　　处：《农业环境科学学报》2010年第2期276-281,共6页Journal of Agro-Environment Science

基　　金：国家高技术研究发展计划(863计划)"有机氯农药类污染场地土壤修复技术设备研发与示范"(2009AA063103);中央级公益性科研院所基本科研业务专项"污染土壤快速洗涤修复技术及装置的初步研发"(国47012)

摘　　要：以苏南某滴滴涕类化合物(DDTs)污染场地土壤为研究对象,进行实验室批量洗脱试验,研究了环境友好型表面活性剂Tween80对土壤中DDTs的增溶洗脱效果及其影响因素。结果表明,Tween80显著地增加了DDTs表观溶解度,在临界胶束浓度(CMC)以上对DDTs的增溶曲线呈指数衰减函数关系,DDTs各组分洗脱量顺序为4,4′-DDT>4,4′-DDD>2,4′-DDD>2,4′-DDT。Tween80的浓度、洗脱次数及土壤吸附作用共同影响其对DDTs的洗脱效果。去离子水能有效去除土壤中残留Tween80,Tween80解吸附率最高可达72.66%,大大降低了Tween80二次污染土壤的风险。Tween80增溶和去离子水解吸附联合过程对DDTs洗脱效果产生显著的协同作用。10000mg·L-1浓度条件下Tween80对DDTs的去除率最高为72%,其次为8000mg·L-1的Tween80水溶液,去除率为66.72%。采用8000mg·L-1的Tween80溶液进行土壤洗涤处理,结合其他修复技术,可能会是修复DDTs污染土壤的有效技术方案之一。Surfactant enhanced soil washing is considered to one of the effective approaches to remove hydrophobic organic compounds from contaminated soils. Batch experiments were performed to study effects of the environment-friendly surfactant Tween 80 on solubilization and elution of DDTs from soil samples taken from a pesticide contaminated site at southern Jiangsu Province. Effects of total 9 concentration levels of Tween 80 at the range of 0-10 000 mg· L^-1 were investigated in this study. The results showed that Tween 80 enhanced desorption and solubilization of DDTs from the soil remarkablely. Concentrations of DDTs in surfactant extracts followed the order：4,4′-DDT〉4,4′-DDD〉 2,4′-DDD〉2,4′-DDT. Desorption and solubilization of DDTs from soil at different concentrations of Tween 80 could be described by exponential decay function. Tween 80 removed significant amount of DDTs from the soil. About 72% DDTs were removed by Tween 80 at solution concentration of 10 000 mg· L^-1, which led to a decrease in DDTs concentration in the soil from 2 780 mg· L^-1to 778 mg· L^-1. At lower Tween 80 concentration of 8 000 mg· L^-1, removal rate of DDTs（66.7% ） was a bit lower than but still comparable to the treatment of Tween 80 at 10 000 mg· L^-1. Most of the Tween 80 （up to 72% for 8 000 mg· L^-1 treatment） left in the soil could be removed by deionized water, which indicated less environmental and ecological risk associated with Tween 80 in the soil. Soil washing with surfactant solution of Tween 80 at 8 000 mg· L^-1 , in combination with other remediation technologies, could be one of the promising solutions to DDTs contaminated soils.

关 键 词：TWEEN 80 DDTS 污染场地 增溶洗脱 修复 

分 类 号：X53[环境科学与工程—环境工程]