Coupling Leaching-Bioremediation for Petroleum-Contaminated Soils

Petroleum-contaminated soils are difficult to remediate due to a wide range of point/nonpoint sources of pollution and complex components. Here, a new leaching agent system was developed and synthesized, including oligomers, to construct the leaching process and optimize the soil leaching process parameters. The new agent has improved skeleton structure, green bio-based surfactant molecules, and synergists. Based on the characteristics of the leaching soil and its flora structure, more than 60 strains of petroleum degradation bacteria were isolated and screened. Furthermore, suitable bacteria for degradation were cultivated, the nutritional formula and process flow were optimized, and the microbial agent formula for heavy oil, polycyclic aromatic hydrocarbons and other pollutants were established. According to the physical characteristics of different types of oily sludge and soil, an economical and efficient remediation technology system and supporting implementation process were established, and finally, a "leaching-bioremediation" coupling treatment process was formed. The PHs content of the actual contaminated soil after the treatment was lower than 0.45%, and 12,000 t of PHs contaminated soil was remediated. Through the study of the elution-bioremediation process, the establishment of economical and environmentally friendly remediation technology and the process will improve our knowledge to solve the sudden oil pollution in contaminated areas and the environmental protection solution of historical problems.