气相抽提法修复油污土壤的影响因素研究

Study on Influence Factors of Soil Vapor Extraction Restoring Oil-contaminated Soil

为了探明多孔介质颗粒粒径对土壤气相抽提技术(SVE)修复效果的影响,选用广泛使用的汽油为污染物,采用一维土柱真空抽气模拟SVE过程,研究了不同通气流量下砂样中对汽油的去除过程。结果表明,加大通风流量可提高砂样中汽油去除速率,但存在最佳通风流量。Elovich动力学方程可描述砂样中汽油的去除过程,常数a与通风流量呈线性正相关,汽油损失速率b与通风流量之间的关系可用二项式描述。砂样中汽油去除率均在97%以上,但平均粒径为0.214 mm的砂样中汽油去除率最大,为99.9%。汽油损失速率b与砂样平均粒径呈线性负相关,而常数a随平均粒径的增大而增大的趋势可用对数方程表达。

In order to grasp the effect of porous media＇s particle size on the restoring effectiveness of soil vapor extraction technology（SVE）,gasoline was chosen as the pollutant.The restoring process of SVE under different ventilation flow was simulated in one-dimensional soil column extracted by vacuum air pump.The results showed that increasing ventilation flow could improve the removal rates of gasoline in sand samples,but there was the best ventilation flow.Elovich dynamics equation could describe the removal process of gasoline,and the linear could describe the relationship between ventilation flow and constant a.While the binomial could express the relationship between ventilation flow and gasoline loss rate b.The removal rates of gasoline in all sand samples was above 97%,but the removal rate of SY2 is the biggest which was 99.9%.The relationships between the mean grain size with b and a could be described by linear and logarithmic equations respectively.