堆肥-生物强化对重度石油污染土壤的修复作用

为解决微生物强化修复油污土壤过程中降解菌在低温环境下活性较低的问题,利用有机堆肥作为固体培养基对降解菌进行扩大培养,将获得的降解菌-堆肥制剂施入油污土壤中进行修复研究.利用重量法和GC-MS分析土壤中石油烃含量变化,利用Illumina Mi Seq对土壤微生物群落结构进行分析.结果表明,利用堆肥作为固体基质可对降解菌进行扩大培养.低温环境下利用堆肥-降解菌制剂对油污土壤修复30 d,土壤中石油烃、烷烃、多环芳烃去除率分别为27.0%、19.6%、10.0%;自然放置的土壤中3种烃去除率分别为4.5%、9.5%、2.3%.加入降解菌-堆肥制剂进行修复的土壤香农指数和Ace指数分别由4.42和1718.5增加为5.30和2170.5;土壤中变形菌门(Proteobacteria)和放线菌门(Actinobacteria)所占丰度由53.4%和25.9%分别降低至48.9%和14.1%,拟杆菌门(Bacteroidetes)所占丰度由5.0%增加至24.5%.属水平上,不动细菌属(Acinetobacter)和假单胞菌属(Pseudomonas)所占丰度由0.02%和3.4%分别提高至15.2%和4.6%.研究结果表明,在低温条件下向石油污染土壤中施入降解菌-堆肥制剂可提高土壤中的石油烃去除率,并使土壤微生物群落结构发生明显变化.

Remediation of Petroleum-Contaminated Soil Using a Bioaugmented Compost Technique

Bioaugmented compost was created by inoculating petroleum-degrading bacteria into mature compost. The petroleum hydrocarbon degradation efficiencies were investigated by applying this enhanced compost to petroleum-contaminated soil under low temperatures. The results showed that the degrading bacteria can be enriched in the mature compost. After 30 d of remediation, the removal efficiency of TPH, alkanes, and PAHs in the soil was 27.0%, 19.6%, and 10.0%, compared to natural attenuation (CK), which was 4.5%, 9.5%, and 2.3%, respectively. In response to remediation, the relative abundance of Proteobacteria and Actinobacteria phyla decreased from 53.4% and 25.9% to 48.9% and 14.1%, respectively, and Bacteroidetes phylum increased from 5.0% to 24.5%. At the genus level, the relative abundance of Acinetobacter and Pseudomonas increased from 0.02% and 3.4% to 15.2% and 4.6%, respectively. The results indicated that the bioaugmented compost may efficiently facilitate and speed up the bioremediation of petroleum-contaminated soil under low-temperature conditions. Soil microbial diversity and structure of microbial communities are sensitive to the remediation.