石油污染土壤的生态风险评价和生物修复Ⅲ.石油污染土壤的植物—微生物联合修复

ECO-RISK ASSESSMENT AND BIOREMEDIATION OF PETROLEUM CONTAMINATED SOIL Ⅲ.PHYTO-MICROBIAL REMEDIATION OF PETROLEUM CONTAMINATED SOIL

在对石油污染土壤理化性质和微生物数量研究的基础上,通过接种含石油降解菌的菌剂、添加营养、定期翻动以及栽种植物等方式对其进行了修复。试验表明,添加氮磷等营养后,土壤中的烃降解菌明显增加,石油降解速率显著加快,但接种菌剂以及定期翻动对降解率没有显著影响。在修复试验进行到120 d后,对部分处理进行了植物修复。试验表明栽种狼尾草后,土壤中石油降解速率显著加快,生物毒性明显降低。另外,试验结束后对土壤中的总DNA进行了提取和基于16S rDNA V3区的PCR-DGGE研究。结果表明,经过修复处理改变了土壤中优势细菌的群落结构,使土壤细菌多样性增强。

A microcosmic experiment was carried out to evaluate effects of nutrients,citrate,tillage and special inoeula on bioremediation of petroleum contaminated soils. Results show that indigenous microbial population,especially hydro- carbon-degrader, and petroleum removing rate increased significantly with addition of nutrients. But inoculation, addition of citrate and tillage did not show much effect on degrading rate. After 120 days of remediation,pennisetum and alfalfa were planted to study their effects on petroleum degradation,and results show that pennisetum significantly increased petroleum removal rate. In addition, denaturing gradient gel electrophoresis （DGGE） was used to study biodiversity of the bacteria in the soil after bioremediation. The profiles of PCR-DGGE revealed differences in microbial community structure between treatments and a higher level of bacterial diversity in treated soils than in the control as was estimated by counting the total number of bands visualized.