阴-非混合表面活性剂对DNAPLs的增溶作用  

On solubilization of DNAPLs by mixed anionic-nonionic surfactants

作　　者：董雯娟[1] 赵保卫[1] 蒋兵[1] 徐谨[1] 

机构地区：[1]兰州交通大学环境与市政工程学院,兰州730070

出　　处：《安全与环境学报》2007年第2期24-28,共5页Journal of Safety and Environment

基　　金：国家自然科学基金项目(20577018);甘肃省中青年科技基金项目(3ZS042-B25-023);兰州交通大学"青蓝"人才工程项目

摘　　要：表面活性剂增溶修复是一种有效的土壤有机污染修复技术。采用静态平衡法比较研究了单一的阴离子表面活性剂十二烷基硫酸钠(SDS)和非离子表面活性剂聚氧乙烯失水山梨脂肪酸酯醇醚(TW80)及其混合表面活性剂对3种氯代烃化合物氯苯(CB)、1,2-二氯苯(1,2-DCB)和三氯乙烯(TCE)的增溶作用。考察了无机盐离子Na+、Mg2+和Ca2+对增溶作用的影响,以期为土壤和地下水重非水相液体(DNAPLs)污染提供新的修复途径。结果表明,阴-非混合表面活性剂TW80-SDS对3种化合物的增溶效果明显强于单一的阴离子表面活性剂SDS,混合表面活性剂的临界胶束浓度(CMC)随着非离子表面活性剂质量分数的增加而降低,其增溶能力随着非离子表面活性剂质量分数的增加而增加,对污染物的增溶程度排序为三氯乙烯>氯苯>1,2-二氯苯。表面活性剂在临界胶束浓度以上,对有机物的分配系数Kmc与有机物的辛醇-水分配系数Kow相当,而增溶比与有机物的水溶解度呈正相关,与Kow、Kmc、溶质的摩尔体积和表面活性剂的亲水-亲油平衡值HLB呈负相关。Na+、Mg2+和Ca2+能增大氯苯在表面活性剂中的表观溶解度,阴非离子表面活性剂SDS与TW80混合后能提高表面活性剂的抗硬水能力,提高增溶效率。Surfactant-enhanced remediation （SER） is considered to be one of the effective approaches to removing the absorbed hydrophobic organic compounds from the contaminated soils. The present paper is just aimed at studying the solubilization of DNAPLs through mixed anionic-nonionic surfactants experiments with chlorobenzene （CB）, 1,2 - dichlorobenzene （ 1,2 - DCB ） and trichloroethylene （TCE） by micellar solutions of single anionic surfactant sodium dodecyl sulfate （SDS） and single nonionic surfactant （TW80） and/or the mixed anionic-nonionic surfactants with a static equilibrium method. It has also investigated the influence of inorganic ions Na^＋ , Mg^2＋ and Ca^2＋ upon the solubilization. As a result, our study enables us to supply a new remediation method for the contaminated soil and groundwater by dense non-aqueous phase liquids （DNAPLs）. Our study results also prove that the solubilization effect of the organic contaminants by the mixed surfactants can significantly be enhanced compared with the single anionic surfactant SDS. Whereas the critical micellar concentration （CMC） can be decreased, the solubility can be increased as long as the mass ratio of nonionic surfactant increases. As the solubility enhancement efficiency of the different compounds follow the order of TCE 〉 CB 〉 1, 2 - DCB, the partition coefficient （Kmc） between the micellar phase and water by the surfactant can be made near to octanol-water partition coefficient （Kow） . In addition, the weight of the solubilization ratio （WSR） appears to be positively relative to the water solubility of the organic contaminants and negatively correlates to Kmc, Kow, the molar volume of the solutes and the hydrophile-lypophile balance value （HLB） of the surfactant. Na^＋ , Mg^2＋ and Ca^2＋ can increase the apparent solubility of CB in the surfactant. Thus, it can be seen that the mixed surfactant can prove to be able to greatly enhance the resistance to hard water and heighten the solubilization e

关 键 词：土壤环境学 混合表面活性剂 DNAPLs 无机盐离子 增溶作用 

分 类 号：X53[环境科学与工程—环境工程]