To efficiently remediate oil-contaminated soil, the degradation characteristics of petroleum hydrocarbons were explored using composite petroleum-degrading flora. The results showed that the degradation rates of the J0, H, HN, HK, and HKN groups were 9.82%, 33.22%, 47.93%, 41.36%, and 61.06%, respectively, which showed that indigenous microorganisms had certain degradation effects on petroleum hydrocarbons. According to the correlation analysis among various environmental factors in the soil, the content of petroleum hydrocarbon in the soil was positively correlated with total nitrogen, total phosphorus, soluble salinity, and organic matter （P<0.01）, and the content of petroleum hydrocarbon was negatively correlated with soil dehydrogenase （P<0.01）. The composite petroleum-degrading bacteria with five types of bacteria had the best degradation effect on petroleum hydrocarbons, and the degradation rate could reach 61.03%； the content of residual petroleum hydrocarbons was less than 200 mg·kg-1, and the degradation rate of composite microorganisms increased by approximately 51.76%. In the soil, the abundance of species was more uniform, and the degradation of petroleum hydrocarbons was more thorough, providing a theoretical basis for further remediation of petroleum-contaminated soil.
Keywords: bioremediation; compound flora; degradation rate; oil-contaminated soil; petroleum degradation.