摘要
表面活性剂增强修复技术(SER)是目前行之有效的有机污染土壤修复技术,但SER技术存在表面活性剂与污染物分离困难、易导致二次污染、成本高等问题.基于此,提出采用具有电化学开关特性的表面活性剂(N,N-二甲基二茂铁甲基十二烷基溴化铵,Fc12)代替SER技术中的常规表面活性剂,发展基于开关表面活性剂的可逆增强修复技术(RSER).选取芘作为目标物,研究了Fc12在氧化和还原态对芘的增溶作用以及常见环境因素,如pH和温度对Fc12可逆增溶的影响.结果表明,相对于氧化态Fc12,还原态Fc12在其临界胶束浓度(CMC)以上时对芘表现出显著的增溶作用,且增溶能力随表面活性剂浓度增大而增强.温度对Fc12的增溶作用影响显著,例如,还原态Fc12在浓度为3 mmol·L-1、25℃条件下时,芘的表观溶解度为0.779 mg·L-1,当温度增加到40℃时,芘的表观溶解度为0.971 mg·L-1,其表观溶解度增加了24.6%;但氧化态条件下,芘的表观溶解度仅增加了6.5%;芘的解吸率(芘在还原和氧化态Fc12的表观溶解度差值与还原态Fc12增溶芘的比值)由63.67%增加到71.27%.pH也显著影响Fc12的增溶,当pH值在6—10范围变化时,还原态Fc12的增溶作用呈现先增加后减小的趋势,且在pH 9附近增溶能力最强,而pH 8时芘的解吸果最好.
Surfactant enhanced remediation(SER)is currently an effective remediation technology for organic contaminated soil.However,traditional SER technology has many drawbacks in the separation of surfactants from contaminants,which may easily cause secondary pollution and high cost.The purpose of this study was to develop a reversible surfactant-enhanced remediation technology(RSER)using a surfactant(N,N-dimethylferrocenylmethyldodecyl ammonium bromide,Fc12)with electrochemical switching properties instead of the conventional surfactant.The solubilization of pyrene by the oxidized and reduced states of Fc12 was investigated,and the effects of conventional environmental factors such as pH and temperature on Fc12 solubilization were studied.The results showed that compared with the oxidized Fc12,the reduced Fc12 displayed significant solubilization of pyrene above its critical micelle concentration(CMC),and the solubilization ability was enhanced with the increase of surfactant concentration.Temperature had a significant effect on the solubilization of Fc12.For example,for the reduced Fc12,the apparent solubility of 3 mmol·L-1 pyrene was 0.779 mg·L-1 at 25℃.When the temperature was increased to 40℃,the apparent solubilityincreased by 24.6%to 0.971 mg·L-1.However,for the oxidized Fc12,the apparent solubility of pyrene increased merdly by 6.5%merely.The release rate of pyrene increased from 63.67%to 71.27%.pH also showed significant effect on the solubilization of Fc12.When the pH was changed from 6 to 10,the solubilization of the reduced Fc12 initially increased and then decreased,the solubility of pyrene reached the maximum value around pH 9,while at pH 8,a better release effect was deserved.
作者
胡晶
田森林
周春坚
刘相良
李英杰
HU Jing;TIAN Senlin;ZHOU Chunjian;LIU Xiangliang;LI Yingjie(Faculty of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming,650500,China)
出处
《环境化学》
CAS
CSCD
北大核心
2020年第2期475-481,共7页
Environmental Chemistry
基金
国家自然科学基金(41761072)资助。
关键词
电化学开关表面活性剂
二茂铁表面活性剂
可逆增溶
芘
多环芳烃
土壤修复
electrochemical switching surfactant
ferrocene surfactant
reversible solubilization
pyrene
polycyclic aromatic hydrocarbons
soil repair
