表面活性剂淋洗法修复硝基苯污染土壤的实验研究

发布时间：2018-01-04 23:12

本文关键词：表面活性剂淋洗法修复硝基苯污染土壤的实验研究　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：表面活性剂淋洗法修复速度快、成本低,它通过降低土壤界面张力,增加硝基苯的溶解性,促进硝基苯随淋洗液的迁移,从而增加了淋洗效率,达到修复目的,因此用于修复硝基苯污染土壤具有良好的前景。本文针对高污染强度的硝基苯污染土壤,研究了阴离子表面活性剂十二烷基硫酸钠(SDS)、十二烷基苯磺酸钠(SDBS),非离子表面活性剂聚氧乙烯(80)失水山梨醇单油酸酯(Tween80)、聚乙二醇辛基苯基醚(100)(TritonX-100)对硝基苯的增溶作用、解吸作用。确定了最佳淋洗剂并进行柱实验,分析并研究了表面活性剂浓度和流速对淋洗实验的影响,为表面活性剂淋洗法修复硝基苯污染土壤的实际应用提供实验依据。根据实验得到以下结论:(1)四种典型表面活性剂对硝基苯的增溶能力大小顺序为:Tween80TritonX-100SDBSSDS,非离子表面活性剂的增溶能力大于阴离子表面活性剂。四种表面活性剂对硝基苯的解吸能力大小顺序为:SDBSSDSTween80TritonX-100,阴离子表面活性剂的解吸能力大于非离子表面活性剂。(2)通过清水及表面活性剂SDBS、SDS淋洗修复硝基苯污染土壤的柱实验可以得出:清水淋洗污染土柱的最佳流速为1mL/min,硝基苯的最高去除率为82.8%;表面活性剂SDBS淋洗污染土柱的最佳浓度为1000mg/L,最佳流速为2mL/min,硝基苯的最高去除率为80.3%;表面活性剂SDS淋洗污染土柱的最佳浓度为2000mg/L,最佳流速为1mL/min,硝基苯的最高去除率为74.4%。淋洗的效果大小顺序为:清水SDBSSDS。(3)在淋洗的过程中,表面活性剂被大量吸附在土壤上,导致淋洗液的有效浓度降低,影响其增溶作用的效果。此外,随着淋洗过程的进行,吸附在土壤上的表面活性剂不仅不能起到增溶作用,反而吸附被淋洗出的硝基苯,因而,硝基苯的去除率有所减少,清水淋洗的效果大于表面活性剂SDBS、SDS。(4)对于本实验条件下的土壤,由于硝基苯具有一定水溶性,不需要添加表面活性剂,清水淋洗即可获得较好的去除效果。淋洗后的土壤满足《展览会用地土壤环境质量评价标准(暂行)HJ350-2007》B级标准100mg/kg。
[Abstract]:The surfactant leaching method has the advantages of fast recovery speed and low cost. By reducing the soil interfacial tension, increasing the solubility of nitrobenzene and promoting the migration of nitrobenzene with the eluate, the elution efficiency is increased and the purpose of remediation is achieved. Therefore, there is a good prospect for remediation of nitrobenzene contaminated soil. In this paper, the anionic surfactant 12 alkyl sodium sulfate (SDSs) was studied for nitrobenzene contaminated soil with high pollution intensity. 12 sodium alkylbenzenesulfonate, Nonionic surfactant polyoxyethylene 80) sorbitol monooleate (Tween80). The solubilization and desorption of nitrobenzene by polyethylene glycol octyl phenyl ether 100 (Triton X-100). The optimum eluent was determined and the column experiment was carried out. The effects of surfactant concentration and flow rate on the elution experiment were analyzed and studied. It provides experimental basis for the practical application of surfactant elution method in remediation of nitrobenzene contaminated soil. The following conclusions are obtained from the experiment: 1). The solubilization ability of four typical surfactants for nitrobenzene was in the order of: Tween80 Triton X-100SDBSSDS. The solubilization ability of Nonionic surfactants is greater than that of anionic surfactants. SDBSSDSTween80TritonX-100. The desorption ability of anionic surfactants is higher than that of Nonionic surfactants. The results of column experiment of SDS elution and remediation of nitrobenzene contaminated soil showed that the optimum flow rate was 1 mL / min and the highest removal rate of nitrobenzene was 82.8%. The optimum concentration of surfactant SDBS eluting contaminated soil column is 1000 mg / L, the optimum flow rate is 2 mL / min, and the highest removal rate of nitrobenzene is 80.3%. The optimum concentration of surfactant SDS eluting contaminated soil column is 2000mg / L and the optimum flow rate is 1mL / min. The highest removal rate of nitrobenzene was 74.4%. The order of elution effect was as follows: SDBSSDS.3) in the process of leaching, surfactants were adsorbed on the soil in large quantities. As a result, the effective concentration of eluate decreased, which affected the effect of solubilization. In addition, with the process of leaching, the surfactant adsorbed on the soil could not play the role of solubilization. Instead of adsorbing the eluted nitrobenzene, the removal rate of nitrobenzene was reduced, and the effect of clean water elution was higher than that of surfactant SDBS- SDS.4) for the soil under this experimental condition. Because nitrobenzene is water-soluble, no surfactant is needed. The soil after elution can meet the evaluation standard of soil environmental quality of exhibition land (temporary HJ350-2007 > B grade standard 100mg / kg).
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53

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