土壤气相抽提法去除红壤中挥发性有机污染物的影响因素研究
Study on influencing factors in removal of volatile organic compounds from red earth by soil vapor extraction
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摘要: 土壤气相抽提技术（SVE）是一种安全、经济、高效的土壤治理技术，广泛应用于不饱和土壤中挥发性有机污染物的去除。本实验以我国南方典型土壤红壤（粘性较大的土壤）为实验土样，选用最常见的挥发性有机物苯作为污染物，采用一维土柱通风模拟SVE过程，研究了通风流量、土壤含水率以及间歇操作对苯污染红壤去污过程的影响。结果表明，在各土柱垂向气相中苯浓度变化趋势一致，通风初期浓度迅速降低后进入长时间的拖尾阶段，拖尾阶段初期进行间歇操作可降低能耗达到较经济的治理效果。通风流量与土壤含水率是影响净化时间和修复效果的重要因素，两Abstract: Soil vapor extraction （SVE）has been effectively used for removal of volatile organic compounds (VOCs) from unsaturated soil, it holds security, economy and high efficiency properties. Column-venting experiment was used to simulate the soil vapor extraction in the typical red earth in south China. Benzene, one of the most common contaminants in petroleum hydrocarbons, was selected. The effects of the vapor flow rate, soil water content and pulsed extraction were studied. The results showed that the gas concentration vertical distribution of benzene during the soil column ventilation had the same trend. At the initial stages of the venting, the concentration of benzene was rapidly reduced and then held long time tail effect, in initial stage of which pulsed extraction may decrease energy cost. The results also showed that the vapor flow rate and soil water content were two of the most important factors on SVE, and they both had the best values. When the vapor flow rate was 600 mL/min and the soil water content was 17.2% the best remediation efficiency has been reached.
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Key words:
- soil vapor extraction /
- red earth /
- benzene /
- vapor flow rate /
- soil water content
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