表面活性剂和螯合剂强化Na_2S_2O_8/Fe^(2+)修复石油污染土壤  

Remediation of petroleum contaminated soil by Na_2S_2O_8/Fe^(2+) enhanced by surfactant and Chelating agent

作　　者：王丽萍[1] 卫少华 李丹 韩旭[1] 许锐伟 WANG Liping;WEI Shaohua;LI Dan;HAN Xu;XU Ruiwei(Engineering Research Center of Ministry of Education for Mine Ecological Restoration,School of Environment Science and Spatial Informatics,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]中国矿业大学环境与测绘学院矿山生态修复教育部工程研究中心,江苏徐州221116

出　　处：《中国矿业大学学报》2019年第3期640-646,共7页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(51778612)

摘　　要：采用Na_2S_2O_8/Fe^(2+)氧化降解污染土壤中的石油烃(TPH),考察了不同初始pH下Na_2S_2O_8与Fe^(2+)摩尔比对TPH降解的影响,研究了表面活性剂Triton X-100和3种螯合剂(柠檬酸、草酸和β-环糊精)对TPH降解的强化作用.研究结果表明:当pH=7,Na_2S_2O_8与Fe^(2+)摩尔比为2∶1时,TPH降解率最高,为39.8%;当Triton X-100质量浓度为1 250 mg/L时,其增溶作用远大于竞争消耗SO_4^-·的作用,TPH降解率可达最大值48.3%.此条件下进行螯合剂添加实验,结果表明:柠檬酸因竞争消耗SO_4^-·而抑制TPH降解,草酸因螯合Fe^(2+)作用较弱,对TPH降解基本不起促进作用;而β-环糊精因形成一种TPH/β-环糊精/Fe^(2+)三元包合物,使TPH降解率提高至55.6%.Triton X-100和β-环糊精联用能有效促进TPH降解,可能是由于Triton X-100的胶束增溶作用和β-环糊精的包合增溶、螯合Fe^(2+)作用产生的协同效应.Na2S2O8/Fe^2+ was adopted to degrade petroleum hydrocarbon(TPH) in contaminated soil. The effect of molar ratio of Na2S2O8 to Fe^2+ on TPH degradation under different initial pH values was investigated. The enhancement effect of the surfactant Triton X-100 and three kinds of chelating agents(citric acid, oxalic acid and β-cyclodextrin) on TPH degradation was also revealed. The results show that when pH value is 7 and the molar ratio of Na2S2O8 to Fe^2+ is 2∶1, the TPH degradation efficiency reaches the highest, which is 39.8%. When Triton X-100 concentration is 1 250 mg/L, the TPH degradation efficiency is the maximum and reaches 48.3%, which is resulted from the effect of significant solubilization exceeding that of competition for SO4^-·. The experiment of chelating agent addition indicates that citric acid can inhibit the TPH degradation due to its competition for SO4^-·. Oxalic acid hardly promotes the TPH degradation because of the weaker chelation of Fe^2+. Whereas,β-cyclodextrin enhances the TPH degradation by the formation of a TPH/β-cyclodextrin/Fe^2+ ternary complex, which increases the TPH degradation efficiency to 55.6%. The combination of Triton X-100 and β-cyclodextrin could effectively promote the TPH degradation, which is possible due to the synergistic effect of the micellar solubilization of Triton X-100 and the inclusion solubilization and the Fe^2+ chelation of β-cyclodextrin.

关 键 词：石油污染土壤 Na2S2O8/Fe^2+ TRITON X-100 Β-环糊精 协同效应 

分 类 号：X53[环境科学与工程—环境工程]