Bioremediation of Clay With High Oil Content and Biological Response After Restoration

Abstract

The clay with high oil content form soil lumps, which is hard for microbes to repair. In this paper, the bioremediation + biostimulation was applied to improve the bioremediation effect of the soil with high oil content, that modified by local cow dung and sandy soil, the ecological toxicity of the soil after restoration was further analyzed. After 53 days of bioremediation, the degradation efficiency with respect to the total petroleum hydrocarbon (TPH) content reached 76.9% ± 2.2%; the soil bacterial content reached 4.9 × 107 CFU/g soil and the results were better than those in the natural attenuation M1group of experimental soils. The relative abundances of petroleum-degrading bacteria added to M5 remained high (Achromobacter 9.44%, Pseudomonas 31.06%, and Acinetobacter 14.11%), and the proportions of some other indigenous bacteria (Alcanivorax and Paenibacillus) also increased. The toxicity of the bioremediated soil was reduced by seed germination and earthworm survival experiments.