土著微生物原位修复石油污染土壤试验研究

利用当地土著微生物优势菌群,辅以物理和化学的方法,结合当地地质微环境特点,开展了陕北某油井旁的石油污染黄土土壤修复研究。设置两个试验区、一个空白区和一个对照区,在两个试验区中分别加入3%的土著优势菌群制剂,选择优化出的土著菌群经鉴定,主要有：假单胞菌属（Pseudomonas）、微球菌属（Micrococcus）、放线菌属（Actinomayces）、真菌类的青霉属（Penicillium）、曲霉属（Aspergillus）等。试验结果显示：土著优势菌剂一般需要3-7d的延滞期（lag phase）,然后进入对数期（logarithmic phase）;两个试验区土壤中人为添加石油含量分别为1542、1886mg·kg^-1时,经过11-32d原位土著优势微生物菌剂的修复,土壤中的石油污染物降解率可达69.52%-88.11%,而对照区土壤中人为添加的石油含量变化不大,降解率基本在10%以内,说明在自然条件下土壤中石油降解是缓慢的。谷糠黍糠、麦麸两种添加剂对优化菌液的修复效果的作用基本相同。试验过程中对土壤温度、水分、氧和营养物质等影响因素进行了调控,起到了良好的作用。

Experimental study on in-situ remediation of petroleum contaminated soil using indigenous microorganisms

The experiments on in-situ remediation of petroleum contaminated loess soil using indigenous microorganisms were carried out near a petroleum well in Northern Shaanxi province.Based on the characteristics of the local micro-environment,ac-cessorial physical and chemical methods were also used in the bioremediation process.In the field,two testing plots,one blank plot,and one reference plot were designed.Culture with optimized microbial communities was added into two testing plots.The added culture amount was about 3%（in weight）of the testing soil.The optimized microbial communities were primarily identi-fied as Pseudomonas,Micrococcus,Actinomayces,Penicillium,and Aspergillus.The experimental results showed that the opti-mized bacteria had a lag phase for 3 to 7 days,and then entered a logarithmic phase.The concentrations of artificially added pe-troleum in two testing plots were 1 542 mg/kg and 1 886 mg/kg,respectively.After 11 to 32 days in-situ microbial remediation,69.5% to 88.1% petroleum in soils of testing plots was degraded,whereas less than 10% of petroleum in soils of the reference plot was degraded,which indicated that petroleum degradation in soil under natural conditions was slow.The effects of two additives（i.e.,millet bran and wheat bran）on remediation efficiency of optimized microbial communities were almost same.The soil tem-perature,moisture content,oxygen and other nutrient contents play important roles in the remediation process and need to be op-timized accordingly.