柴油污染包气带的气相抽提影响因素

Influencing factors of soil vapor extraction for removal of diesel fuel from vadose zone

气相抽提(SVE)是一种经济、高效的土壤原位修复技术。为了研究介质、介质含水率和通风方式对SVE去除效率的影响,并探讨实验运行过程中包气带不同深度柴油浓度的变化规律,实验利用了有机玻璃柱模拟包气带环境,开展柴油污染的SVE实验。结果表明,对于不同介质,SVE去除粗砂中柴油的效率高于中砂;不同含水率,含水率为1%的粗砂中柴油的去除率大于含水率为12%的粗砂;不同的通风方式,连续通风的效率大于间歇通风。此外,不同深度介质均出现柴油浓度先升高后降低的趋势。

The soil vapor extraction （SVE） is an economical and efficient in situ remediation technology of soil. A series of one-dimensional column experiments were conducted to study the influencing factors for SVE technique, the factors included sand grain size, sand water content and extraction mode, while the changes of concentrations of total petroleum hydrocarbons （TPH） along the depth in vadose zone were analyzed in the opera-tion process. The results indicated that sand grain sizes had a great impact on diesel fuel removal efficiency, the removal in coarse sand was higher than that in medium sand. Water content in the sand had negative impact on the diesel fuel removal efficiency, the removal in coarse sand with water content of 1% was higher than that in coarse sand with 12% water content. Continuous vapor extraction was more efficient than pulsed vapor extrac- tion. Furthermore, concentrations of diesel fuel in different depth of mediums had a tendency to first increase and then decrease.