生物通风修复含石油污染物土壤过程

以苯、甲苯和对二甲苯（BTX）为模拟污染物，研究了生物通风原位土壤修复方法去除土壤中石油污染物的效果.用一维生物通风土柱实验和控制实验对比了有生物降解和无生物降解土柱中BTX的去除情况.在通风后期，控制实验中发现了很长的拖尾阶段，污染物不能进一步被有效去除，而生物通风土柱中由于生物降解作用可使土壤中污染物残留浓度更小，修复效率更高.根据实验数据估算得到生物通风过程中苯、甲苯及对二甲苯的生物降解贡献率分别为17.8%, 30.0% 和 32.3%.还用间歇实验探讨了多组分污染物之间的相互影响作用，发现甲苯的降解能够促进对二甲苯和苯的降解，而对二甲苯的存在则增加了甲苯和苯的降解滞后期.

REMEDIATION OF UNSATURATED SOIL CONTAINING PETROLEUM CONTAMINANTS BY BIOVENTING

A vadose column method designed to simulate the removal of BTX during bioventing was developed in this paper.A soil column without microorganism was used as a control measure for removal of BTX by volatilization merely.During the last period of venting, the long term tailing behavior was found in the control experiment, indicating that venting by itself might be inefficient in achieving a complete cleanup.At the end of experiment, the concentration of residual BTX in bioventing soil column was much smaller than that in the control one due to biodegradation. To determine the role of bioconversion and physical removal of BTX from soil, air and N2 were used,respectively,as flushing gases at a flowrate of 5.0 ml•min^-1.Mass balance analysis of BTX and CO2 indicated that the volatilization-to-biodegradation ratio of benzene, toluene and p-xylene during bioventing experiment are about 17.8%, 30.0% and 32.3%,respectively.Moreover, the iteractions among the BTX contaminants were also explored by batch experiments.Results showed that benzene and p-xylene degradation were accelerated while toluene was being degraded, and the presence of p-xylene increased the lag period for degradation of benzene and toluene.