可降解表面活性剂增效洗脱污染土壤中二氯苯的研究

发布时间：2018-01-25 08:24

本文关键词： 可降解表面活性剂二氯苯洗脱土壤性质　出处：《山西大学》2015年硕士论文　论文类型：学位论文

【摘要】：二氯苯是一种氯代芳香烃化合物,在染料、塑料、农药、医药及日用化工产品的生产中应用广泛。其中,邻二氯苯和对二氯苯由于生产量大,应用广泛,容易在生产和使用过程中进入土壤环境中,危及生物和人体健康。因此,二氯苯污染土壤的修复是环境领域亟待解决的问题之一。表面活性剂(尤其是可降解表面活性剂)增效修复是目前最具应用潜力的土壤有机污染修复技术之一,增溶洗脱是其实现的前提。本研究以邻二氯苯和对二氯苯污染土壤为研究对象,选取生物表面活性剂皂角苷、合成表面活性剂烷基糖苷两种可降解表面活性剂,与表面活性剂Tween80进行对比,研究其对污染土壤中二氯苯的异位洗脱和原位淋洗去除效果,并对应用过程中上述三种表面活性剂对土壤性质的影响进行了研究。主要研究结果如下：(1)皂角苷、烷基糖苷和Tween80对邻二氯苯和对二氯苯的增溶作用在CMC前后随其浓度呈线性关系,增溶顺序为Tween80烷基糖苷皂角苷；而皂角苷和烷基糖苷对土壤中邻二氯苯和对二氯苯的异位洗脱去除效果均优于Tween80;土壤中邻二氯苯和对二氯苯的洗脱过程在360min内可达到平衡,且基本符合4参数2室洗脱动力学方程。(2)皂角苷和烷基糖苷对土壤中邻二氯苯和对二氯苯的原位淋洗去除效果亦优于Tween80,但原位淋洗去除率低于异位洗脱去除率；原位淋洗后表层土壤中邻二氯苯和对二氯苯残留量最低,底层次之,中层最高；随着淋洗液体积的增加,淋洗液中邻二氯苯和对二氯苯浓度整体呈下降趋势,邻二氯苯和对二氯苯累积量呈上升趋势。(3)皂角苷和Tween80可降低土壤pH值,而烷基糖苷可升高土壤pH值；4gL-1皂角苷和Tween80可提高土壤有机质含量；2g L-1皂角苷、烷基糖苷和Tween80可提高土壤CEC。4gL-1皂角苷、烷基糖苷和Tween80可显著提高土壤全氮量、速效磷含量和速效钾含量。4g L-1皂角苷、烷基糖苷和Tween80可显著提高土壤脱氢酶和过氧化氢酶活性；1g L-1皂角苷、烷基糖苷和Tween80可显著提高土壤多酚氧化酶活性。综上所述,与Tween80相比,可降解表面活性剂皂角苷和烷基糖苷对污染土壤中邻二氯苯和对二氯苯的异位洗脱和原位淋洗去除效果更好,且对土壤肥力、养分含量和土壤酶活性的提高作用更为显著。可降解表面活性剂不仅对土壤中二氯苯的修复去除效果较好,而且可以改善土壤性质,为污染土壤的再利用提供保障。
[Abstract]:Dichlorobenzene is a chlorinated aromatic compound, which is widely used in the production of dyes, plastics, pesticides, medicine and daily chemical products, among which o-dichlorobenzene and p-dichlorobenzene are widely used because of their large production capacity. Easy to enter the soil environment during production and use, endangering biological and human health. The remediation of soil contaminated by dichlorobenzene is one of the urgent problems in the field of environment. The synergistic remediation of surfactants (especially degradable surfactants) is one of the most promising remediation techniques for soil organic pollution. Solubilization and elution is the precondition of this study. In this study, biosurfactant saponins were selected to synthesize two biodegradable surfactants, namely o-dichlorobenzene and p-dichlorobenzene contaminated soil. The heterotopic elution and in situ elution of dichlorobenzene in contaminated soil were studied by contrast with surfactant Tween80. The effects of the three surfactants on soil properties were studied. The main results were as follows: 1) saponins. The solubilization of o-dichlorobenzene and p-dichlorobenzene by alkyl glycosides and Tween80 showed a linear relationship with their concentrations before and after CMC, and the order of solubilization was Tween80 alkyl glycosides saponins. However, both saponins and alkyl glycosides were better than Tween80 in the removal of o-dichlorobenzene and p-dichlorobenzene in soil. The elution process of o-dichlorobenzene and p-dichlorobenzene in soil could reach equilibrium within 360 min. The in-situ elution of o-dichlorobenzene and p-dichlorobenzene in soil was also better than that of Tween80. However, the removal rate of in-situ elution was lower than that of ectopic elution. After in-situ leaching, the residues of o-dichlorobenzene and p-dichlorobenzene were the lowest in the topsoil, followed by the bottom layer and the middle layer. The concentration of o-dichlorobenzene and p-dichlorobenzene in the eluate decreased with the increase of the volume of eluent. The accumulation of o-dichlorobenzene and p-dichlorobenzene showed an increasing trend. The saponins and Tween80 decreased the soil pH value, but alkyl glucoside increased the soil pH value. 4g L-1 saponins and Tween80 could increase the content of soil organic matter. 2 g L-1 saponins, alkyl glycosides and Tween80 increased soil CEC.4gL-1 saponins, alkyl glycosides and Tween80 significantly increased soil total nitrogen content. The contents of available phosphorus and available potassium. 4 g L-1 saponins, alkyl glycosides and Tween80 could significantly increase the activities of soil dehydrogenase and catalase. 1g L-1 saponins, alkyl glycosides and Tween80 could significantly increase the activity of soil polyphenol oxidase. In conclusion, compared with Tween80. Biodegradable surfactants saponins and alkyl glycosides were better for the removal of o-dichlorobenzene and p-dichlorobenzene in contaminated soil and in situ elution. Biodegradable surfactants can not only improve the remediation and removal of dichlorobenzene in soil, but also improve the properties of soil. To provide protection for the reuse of contaminated soil.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53

【参考文献】