Remediation of petroleum hydrocarbon contaminated groundwater by biochar immobilized bacterial consortia

With the rapid development of energy industrialization, groundwater has been seriously contaminated by petroleum hydrocarbon. In this study. the C10-C40 components of petroleum hydrocarbons in the groundwater were simulated by diesel to screen two strains of efficient petroleum hydrocarbon-degrading bacteria, that is. Lysinibacillus and Bacillus. Then. the petroleum hydrocarbon degradation material with high stability of adsorption and degradation was prepared using microbial immobilization technology. Scanning electron microscopy results indicated that this material had excellent adsorption capacity. The degradation kinetics experiment showed that the degradation of petroleum hydrocarbon followed the second-order kinetic model. Single-factor experiments combined with the response surface method were used to design the orthogonal experiment to explore the optimal conditions for the degradation of this material. By controlling the pH being 6.93, initial concentration of petroleum hydrocarbon being 2803.17 mg.L-1, immobilization time being 26.96 h, and the immobilized microorganisms inoculum being 3.62 g, the best degradation rate of 70.51% was obtained after 7 days. In conclusion, the microbial immobilization material can adapt to the high concentration of petroleum hydrocarbons in groundwater, and significantly reduce the concentration of petroleum hydrocarbons. Our study provides important references for the remediation of petroleum hydrocarbons in groundwater.