生物菌剂对石油污染土壤生物修复作用的研究

Bioremediation of Petroleum Hydrocarbon Contaminated Soil by Bioaugmentation Products

在实验室条件下,研究了生物菌剂的投加量、投加方式及环境温度对石油污染土壤的修复作用.结果表明,土壤中石油烃的降解效果与生物菌剂的投加量呈正相关,当生物菌剂投加量为0.6 mg.kg-1时,修复48 d后,石油烃的降解率为87%.GC-MS分析结果表明,石油污染原土中烷烃的含量最高为82.1%,其次为烯烃,含量为16%,还含有少量的胡萝卜烷、烷基萘、甾烷和藿烷.添加生物菌剂修复40 d后,峰的数量由32个减少为14个,表明异构烷烃、烯烃、胡萝卜烷全部被降解,残留的物质为较难降解的正构烷烃、藿烷和甾烷,呈前高后低的峰形,即接种细菌优先降解高碳组分,将长链的烷烃降解为短链的烷烃,随着生物菌剂投加量的增加,土壤中残留石油烃的含量逐渐降低.一次加入生物菌剂修复48 d后的峰高明显低于分2次加入的相应值,故一次性全部加入生物菌剂是最佳的投加方式.温度是限制石油污染土壤生物修复的重要环境因素,当温度为30℃,第48 d的降解率可达80%,当温度为20℃,第48 d的降解率可达60%,温度高有利于土壤中石油烃的降解,加快修复速率.

In an experimental investigation of bioaugrnentation products affected on the petroleum contaminated soil. The influence of the bioangmentation products dose, injections and temperature on bioremediation were studied. The results showed that the degradation rate was related positively to the amount of inoculation, when the dose was increased to 0.6 mg＂ kg-1 , total petroleum hydrocarbon（TPH） degradation rate was 87 % in 48 days. The results of GC-MS indicated that the dominant petroleum constituents in off-contaminated raw soil were 82.1% nalkane, 16% alkene and little of others hydrocarbons, such as carotane, alkylnaphthalenes, hopanes, and steranes. The peaks amount of GC profile decreased from 32 to 14 after 40 clays of bioremediation, this result indicated that branched alkanes, alkene, and alkylnaphthalenes were thoroughly degraded, then line alkanes, hopanes, and steranes were left in soil. In addition, the longer part of n-alkane were degraded with rate relatively higher,while the residual fraction at the end of the test is shorter part of n-alkane because bacteria degraded the longer n-alkane to shorter. The shorter n-alkane concentration decreased with increasing inoculation. Onetime injection of bioaugmentation products into soil clearly improved the biodegradation efficiency higher than injection of bioaugmentation products in turn. Soil temperature also affected TPH degradation rate.when it was 30℃, TPH rate reached 80%, where as when it was 20℃, the TPH rate was lower to 60%, which indicated higher temperature improved TPH degradation and accelerated bioremediation.