Toward Green Remediation: A Life Cycle Assessment and Parameter Optimization Study on Petroleum-Polluted Soil Treatment

Employing eco-friendly and low-carbon methods to restore petroleum-polluted soil is a growing trend. However, the low-carbon remediation theories and methods for petroleum-polluted soil are still in their early stages. Herein, the carbon footprint and environmental impacts of different petroleum-polluted soil remediation methods were studied based on life cycle assessment (LCA). It was found that the carbon footprint and environmental impacts of the solidification/stabilization (S/S) method were much lower than those of pyrolysis and chemical oxidation methods. Moreover, compared with other S/S materials, the carbon footprint of lime–fly ash solidification for petroleum-polluted soil was the lowest, at only 12.72 kg CO2 eq. Moreover, its unconfined compressive strength (UCS) increased by 700% compared to the untreated petroleum-polluted soil. On this basis, the response surface method was further employed to optimize remediation parameters using carbon footprint and UCS growth rate as response variables. The results showed that the optimal parameters for solidifying petroleum-polluted soil were lime content of 10.41%, fly ash content of 21.89%, and a curing time of 27 days. This study provides the important theoretical basis and practical guidance for the low-carbon and efficient remediation of petroleum-polluted soil.