柴油污染土壤修复砂箱试验

Sandbox Test of Diesel Hydrocarbon Removal From Soil by Soil Venting

通过室内通风预试验和砂箱试验,以通风前后土壤柴油烃含量变化,研究了低速(8mL/min)间歇通风(8h/d)对经长期搁置柴油污染土壤的修复效果和厌氧生物降解作用.结果表明:低速间歇通风对土壤污染区柴油去除效果显著,通风6d后,柴油烃去除率约为21.57%,远高于土柱预试验修复效率.砂箱尾气CO2/O2/TVOC组分变化分析表明,通风过程中存在微生物降解柴油烃并释放CO2过程.土壤柴油烃去除机理分析结果表明,土壤柴油污染物不完全生物降解去除比率达95.35%,主要是砂箱密封静置期间微生物厌氧活动造成.

The remediation efficiency of diesel-contaminated soil which was placed for a long period by pulse soil venting with low air flow was studied through advance column experiment and sandbox experiments of the residuel diesel hydrocarbon concentration change in soil after soil venting. The results show that after six days the remediation efficiency of pulse soil venting with low air flow （8 mL/min,8 h/d） to the diesel-contaminated soil placed for 5 months was 21.57%-60.14%, which was higher than that of preparative experiment in soil column. The further analysis of the mass fractions of TVOC/CO2/O2 in tailing gas during soil venting process shows that there is the activity of microbe in contaminated soil. The diesel removal mechanism analysis from the residual diesel mass fraction in soil and the TVOC/CO2 mass fraction in tailing gas show that the removal by microbial incomplete degradation is 95.35%, which is the main cause of diesel removal in sandox.