Remediation and regulatory factors of petroleum hydrocarbon contaminated soil on site through Fe2+/Na2S2O8-Enterobacter himalayensis GZ6

Abstract

The low-dose Fe2+/Na2S2O8-Enterobacter himalayensis GZ6 process can provide green, efficient, and sustainable remediation of organic contaminated soil. Adding 1.5 % (v/v) persulfate (PS) for oxidation, the residual concentration of total petroleum hydrocarbon (TPH) in the soil decreased from 16,622.87 mg/kg to 7663.10 mg/kg, with a removal rate of 53.90 %. After 103 days of PS-Enterobacter himalayensis GZ6 group, the degradation rate of TPH was 15 % higher than that of PS-indigenous bacteria group (71 %) and single bioremediation group (71 %). The effects of indigenous bacteria and abiotic environmental parameters on the remediation performance of PS-Enterobacter himalayensis GZ6 were quantified. Both C10-C17 and C18-C30 were oxidized and biodegradable, with PS mainly oxidizing C18-C30 and microorganisms mainly degrading C10-C17, and C30-C40 could only be removed by biodegradation. Enterobacter himalayensis GZ6 made an important contribution in the middle stage of remediation, and activated indigenous dominant archaea and bacteria, such as Nitrosopumilales archaeon and Acinetobacter indicus. The research results provided theoretical and technical support for in-situ remediation of petroleum hydrocarbons contaminated sites.