施用生物菌剂对油水淹地污染土壤的修复研究

Remediation of Oil-containing Wastewater Contaminated Soil Using Microbial Agent

从油水淹地污染土壤中获得石油降解菌,筛选出产表面活性剂降解菌1株(H-6)和优势菌6株(H-1、H-17、H-18、H-19、H-20、H-23),以H-6为中心,再任选3株优势菌株构建菌群,最终得到高效石油降解菌群C5(H-1、H-6、H-18、H-19),以秸秆为载体将C5菌群制备成固体生物菌剂(MA),通过室内培养试验和田间试验测定油水淹地污染土壤的石油含量、盐碱性指标及微生物性质,探究MA菌剂对油水淹地污染土壤的修复情况。室内培养试验和田间试验结果表明,污染土壤中石油的降解效果都很显著,MA菌剂中的细菌具有嗜盐菌的特征,使污染土壤的p H、电导率、全盐量、钠吸附比(SAR)和总碱度(TA)显著低于未添加菌剂处理,添加菌剂后污染土壤的微生物数量、微生物量碳、可溶性盐离子组成也都优于未添加菌剂处理。因此,MA菌剂对油水淹地这种油盐复合污染土壤具有较好的生物修复效果,为油水淹地污染土壤的大规模修复提供了技术支持。

Soil contamination by oil-containing wastewater becomes an environmental issue in oilfields, which profoundly affects crop growth. In this study, one bacterium strain(H6)producing surfactants and 6 dominant bacterium strains(H-1, H-17, H-18, H-19, H-20,H-23)were screened from oil-degrading bacteria strains. Then the bacterial combinations of H-6 with any three dominant strains were assessed for their oil-degrading efficiency. A high efficient oil-degrading bacterium group C5(H-1, H-6, H-18, H-19)was obtained. A solid microbial agent(MA)was produced by inoculating the bacterium group C5 on straw. Bioremediation of oil contaminated soil by MA was examined in both indoor simulation experiment and field trial by determining oil content, salt index and microbiological properties. In both experiments, applying MA significantly enhanced oil degradation, compared to the control. The bacteria in MA showed halophilic characteristics. Significantly lower p H, electrical conductivity, salt content, sodium adsorption ratio(SAR)and total alkalinity(TA)were observed in soils with MA than in the control. Applying MA microbial agent also improved microbial population, microbial biomass carbon and soluble salt ion composition. These results show that the solid MA may be applied to remediate oil-contaminated soils on large scale.