摘要
采用蛭石模拟土壤,研究稠油污染土壤的臭氧预处理工艺。在臭氧浓度为50mg·L-1,气体流量为0.2m3·h-1的条件下,分析了臭氧通气时间、水土比、污染土壤陈化时间和污染浓度对土壤中石油烃去除率的影响。结果表明,模拟稠油污染土壤的最佳处理条件为臭氧通气30min,水土比为0∶1,此时总石油烃降解率为40.97%,其中芳烃降解率最高为90.18%,其次是饱和烃为61.81%。此外,臭氧预处理可以促使酯类等可溶性石油烃的生成,从而提高稠油的生物可利用率。因而,臭氧预处理能够降低后续处理的负荷,是一种可行的预处理方法。
Biological treatment of heavy oil contaminated soils has been demonstrated to be an inefficient remediation technology. Bioavailability of the contaminants is of great importance for a successful bioremediation, so a chemical pre-treatment step by ozone was used to enhance the biodegradability of heavy oil. Laboratory-scale column experiments were therefore conducted with vermiculite artificially contaminated by heavy crude oil. Particular attention was paid to the removal of total petroleum hydrocarbons with the effects of ozonation time, soil/ water ratio, contaminated soil aging time and contaminated concentration of simulated soils, when the gas flow were kept at 0.2 m3·h^-1, and the concentration of ozone was 50 mg·L^-1. Under the optimal conditions, ozonation 30 min and the ratio of solution to soil 0：1, the removal rate of total petroleum hydrocarbons, saturated hydrocarbons, and aromatics were up to 40.97%, 61.81% and 90.18%, respectively. And the degradation rate of aromatics was faster than saturated hydrocarbons. Oxidation of heavy oil by ozone resulted in reaction products that had a better solubility in water and thus a better bioavailability. Thus heavy oils were prone to biodegradation. The efficiency of ozone pre-treatment was low when soils were aging for a long time. But ozone pre-treatment gained high efficiency when contaminated concentration of soils was 2%- 5%. So ozone pre-treatment was a feasible treatment method before biodegradation.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2008年第5期1721-1725,共5页
Journal of Agro-Environment Science
基金
国家重点基础研究发展计划项目(973)(2004CB418501)
关键词
稠油污染
模拟土壤
臭氧氧化
预处理
heavy oil contamination
simulated soils
ozonation
pre-treatment
