贫养分低有机质黄绵土中石油烃的生物去除特性及菌群结构变化

Petroleum Hydrocarbon Degradation Characteristics and Microbial Community Shift by Bioremediation in Oligotrophic and Low Organic Matter Soil

为探究陕北油田开采区贫养分低有机质土壤中石油烃的有效去除方法及修复特性,利用生物强化和生物刺激对陕北地区石油污染土壤进行修复研究,比较了两种修复方式对土壤中石油烃的去除效果和对土壤菌群结构多样性的影响.结果表明:相比生物强化修复方式,向土壤中施入氮素进行生物刺激修复更有利于土壤中石油烃的去除:向土壤中加入KNO_(3)调节土壤C/N为100∶20,在含水量为15.1%的条件下修复60 d时,土壤中石油烃去除率达到44.77%;接种降解菌强化修复对石油烃的去除率仅为17.87%.在5.1%和15.1%两种不同含水量条件下,接种的降解菌群可在土壤中生长并存活.外源菌的生长存活和石油烃降解无明显相关关系,影响石油烃降解的非生物因子为土壤养分和含水量,生物因子为土壤菌群的丰富度和均匀度.研究显示,在对污染土壤进行修复时,应“因地制宜”选择适合当地水热条件的修复方式以增加土壤菌群的稳定性,进而提高土壤微生物的代谢活性.

In order to investigate the removal efficiency and remediation characteristics of petroleum hydrocarbons in the oligotrophic and low organic matter soil in the northern of Shaanxi oilfield area,the remediation of petroleum-contaminated soil was studied by bioaugmentation and biostimulation,respectively.The removal efficiency of petroleum hydrocarbons,and the changes of soil microbial community compositions were determined by instrumental analysis and molecular biological technique,respectively.The results showed that biostimulation with nutrients was more effective for petroleum removal than that of bioaugmentation with degrading flora.When soil moisture was adjusted to 15.1%by adding sterile water,and the soil C/N ratio was adjusted to 100∶20 by adding KNO_(3) to the soil,the removal efficiency of petroleum hydrocarbon was 44.77%;while the petroleum removal efficiency was 17.87%when the soil was bioaugmented with petroleum-degrading flora.Under the conditions of 5.1%and 15.1%moisture content,the bioaugmented degrading flora could survive and growth well,but the survival and growth of the bioaugmented flora did not improve the petroleum biodegradation.The nutrients and soil moisture contents were the abiotic factors,while the uniformity and abundance of microbial communities were the biotic factors that influenced petroleum hydrocarbon degradation in the polluted soil.Our study indicated that the suitable remediation methods for local climate conditions should be considered in order to improve the diversity and activity of soil microorganisms.