Surfactant-Enhanced Electroosmotic Flushing in a Tricholrobenzene Contaminated Clayey Soil
Surfactant-Enhanced Electroosmotic Flushing in a Tricholrobenzene Contaminated Clayey Soil
复制标题
表面活性剂增强电渗冲洗三氯苯污染的粘土
DOI：
10.1111/gwat.12631
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Zhang Ming
中科院分区：
文献类型：
--
作者：
Qiao Wenjing;Ye Shujun;Wu Jichun;Zhang Ming
受氯苯等有机污染物污染的场地的补救仍然是一个具有挑战性的问题。电渗冲洗是一种很有前途的方法，它基于电动力学修复机制，用于去除低渗透性土壤中流体中的有机污染物。为了选择能有效增强电渗冲洗的最佳表面活性剂，测试了三种常见的表面活性剂，Triton X-100（EK 2）、吐温80（EK 3）以及十二烷基硫酸钠和Triton X-100的混合物（EK 4），其用Na 2 HPO 4/NaH 2 PO 4溶液缓冲。使用一个装有掺入1，2，4-三氯苯的粘性土壤的三维盒子评估每种表面活性剂的效率，并与不含表面活性剂的试验（EK 1）进行比较。结果表明，缓冲溶液有效地中和了电解产生的H+和OH−。在冲洗液中加入吐温80的EK 3达到最高的电渗渗透率10− 4cm 2/v/s，并在6 d内达到5067 mL的显著高的累积电渗流量（EK 3），分别是EK 1、EK 2和EK 4的6.3、3.4和4.2倍。有420 mL以上的累积EK 4比EK 2的电应用50小时后获得的。非反应性离子的引入可以增加电流，从而有利于阴极。由缓冲液引起的较高pH和非离子表面活性剂的应用都可以使zeta电位更负，从而增加pH。吐温80可以推荐为最佳的冲洗溶液，用于去除现场的有机污染物时，电动修复应用。
Remediation of the sites contaminated with organic contaminants, such as chlorobenzenes, remains a challenging issue. Electroosmotic flushing can be a promising approach which is based on mechanism of electrokinetic remediation for removal of organic contaminants from fluids in low‐permeability soil. To select an optimum surfactant that can effectively enhance electroosmotic flushing, three common surfactants, Triton X‐100 (EK2), Tween 80 (EK3), and a mixture of sodium dodecyl sulfate and Triton X‐100 (EK4) buffered with Na2HPO4/NaH2PO4solution, were tested. The efficiency of each kind of surfactant was evaluated using a three‐dimensional box filled with a clayey soil spiked with 1,2,4‐trichlorobenzene, and compared with a test (EK1) without surfactant. The results demonstrated that the buffer solutions efficiently neutralized H+and OH−produced by electrolysis. EK3 with Tween 80 added in the flushing solution reached the highest electroosmotic permeability of 10−4cm2/v/s and achieved a notably high cumulative electroosmotic flow (EOF) of 5067 mL within 6 d, which was 6.3, 3.4, and 4.2 times higher than that in EK1, EK2, and EK4, respectively. There were 420 mL more cumulative EOF obtained after 50 h of electrical application in EK4 than in EK2. The introduction of nonreactive ions can increase the current, thereby benefiting the EOF. Both the higher pH caused by the buffer and the application of nonionic surfactants can make the zeta potential more negative, thereby increasing the EOF. Tween 80 can be recommended as the best flushing solution for removing organic contaminants from sites when electrokinetic remediation is applied.