石油污染土壤的生物整治研究

Study on Bioremediation of Petroleum-polluted Soil

对被石油污染的包气带土层中微生物生态分布特性进行了调查,并从该土层中分离出159株烃降解细菌和真菌,其中17株可以不同程度地分别利用烷烃(nC_9-nC_(18))和芳烃(酚、萘、苯、甲苯和二甲苯)作为唯一碳源生长。在最适氮源和磷源的条件下,假单胞菌52在7d内可利用石蜡作为碳源,生物量连续增加;3d内可将初始浓度为500mg/L的机油降解99％。投加选育出的混合菌株,进行土壤石油污染的生物整治模拟试验,结果表明,25d内,可将油污的矿化作用提高1倍。投加菌株和补充氮、磷营养,处理初始浓度为15000mg/kg的被原油污染的土壤,8d内土壤中油污去除98.8％,CO_2产生量提高2.8倍。讨论了投加菌种及营养补充对土壤生物整治的贡献率、添加菌剂对消除烃污染、营养补充对烃的矿化作用影响等问题。

A simulated experiment has been performed in the laboratory for bioremediation of soil contaminated with oil wastewater. The feature of microbial ecological distribution in the polluted site was investigated. 159 bacterial and fungal strains capable of degrading hydrocarbons were isolated from various polluted soils, and 17 of them were capable of using hydrocarbons including alkanes(nC8~ nC16)and aromatic hydrocarbons (phenol, naphthalene, benzene, toluene and xylene)as sole carbon source for growing. Under optimum nitrogen and phosphorus nutrition conditions, Pseudomonas sp.52 could grow continuously by using paraffin within the first 7 days of incubation, and engine oil was degraded more than 99% with initial concentration of 500mg/L in 3 days. Strains isolated from contaminated soil were inoculated to 25g soil from polluted site to simulated on-site bioremediation process. Over a period of 25-day experiment, it was observed that mineralization of hydrocarbons was enhanced 1 fold as compared with uninoculation one. An unpolluted soil (25g) was artificially contaminated with petroleum at the concentration of 15000mg/kg, after seeding with hydrocarbons degrading microbes and incubating for 8 days, total petroleum hydrocarbons reduction was as high as 98.8% and CO2 production was as high as 3.8fold compared with control. The contribution rate of bioaugmentation and/or nutrition amendment to bioremediation of petroleum pollution was also discussed.