Soil microbial ecological effect of shale gas oil-based drilling cuttings pyrolysis residue used as soil covering material.

The residue derived from oil-based drilling cutting pyrolysis could be used as paving materials. Some petroleum hydrocarbons remain in the residue after pyrolysis and cause severe environmental pollution. In this study, the soil column leaching experiments were carried out under different leaching amounts, and the vertical migration characteristics of petroleum hydrocarbons in soil and the dynamic response mechanism of microorganisms to petroleum hydrocarbons were analyzed. The result showed that the soil pH value and water content with different leaching amounts did not differ significantly, but the vertical migration ability of each petroleum hydrocarbon component was different. In petroleum hydrocarbon contaminated soil, the relative abundance of Proteobacteria maintained a high level (23.6%-60.7%). At the genus level, the relative abundance of Massilia decreased with the leaching amount increased. According to PICRUSt, Monooxygenase [EC: 1.14.13.-] played a significant role in petroleum hydrocarbon degradation. While Long-chain-fatty-acid-CoA ligase [EC: 6.2.1.3] had the highest relative abundance. By studying the influence of shale gas oil-based drilling cuttings pyrolysis residue on soil physical and chemical properties and soil microorganisms, this work provides scientific ecological assessment for the resource application of pyrolysis residue.