2D-Box Study on Effects of Media Heterogeneity on Remediation of TCE by Steam Enhanced Extraction
Abstract: Steam Enhanced Extraction is a newly developed and promising soil remediation technique for non-aqueous phase liquids (NAPLs) in vadose zone. Mixture of steam and air is injected into the contaminated soil to promote the volatilization of the pollutants. The remediation is a process of NAPLs transformation in unsaturated porous media un-der artificial engineering condition. Removal process and efficiency may be greatly impacted by medium heterogeneity. In this study, trichloroethylene (TCE) removal using Steam Enhanced Extraction was carried out in a 2-dimensional sandbox with three different layered sand structures under unsaturated conditions. Three kinds of sands (coarse, fine and silt) were used to simulate heterogeneous media. The results show that SEE perfectly improves “tailing” effect com-pared to soil vapor extraction (SVE). And the removal ratios from the three experiments in 100 minutes are 89.5%, 88.2% and 85.2%. Meanwhile, there were by-passing flows when gas through the coarse sand and fine sand area, which affected the total removal ratio and process. The layered structure with finer sand, in which the steam and air convection was faster, resulted in faster removal rate and larger removal ratio compared to that with clay sand. In the experiments packed with finer or clay sand, a small amount of NAPL phase TCE was cumulated, which also reduced the total re-move ratio.
文章引用: 王 宁 , 彭胜 , 陈家军 (2013) 介质非均质性对蒸汽强化SVE法修复TCE污染影响的二维土箱模拟研究。 环境保护前沿， 3， 45-51. doi: 10.12677/AEP.2013.32008
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