Sustainable Recovery of the Health of Soil with Old Petroleum Hydrocarbon Contamination through Individual and Microorganism-Assisted Phytoremediation with Lotus corniculatus

Due to the large number of areas contaminated with TPH, there is significant interest in biological remediation technology research, offering a comprehensive and sustainable approach to soil decontamination and health recovery at the same time. This study aimed to investigate the effectiveness of remediating TPH-contaminated soil (6120 mg kg−1) using Lotus corniculatus along with a microorganism consortium (GTC-GVT/2021) isolated from historic TPH-contaminated sites. This study evaluated the removal of TPH and soil health recovery through changes in soil nutrient content, soil enzymatic activity, and the microbiological community. The growth of L. corniculatus was reduced in TPH-contaminated soil, particularly affecting root biomass by 52.17%. Applying inoculum positively affected total plant biomass in uncontaminated (51.44%) and contaminated (33.30%) soil. The GTC-GVT/2021 inoculum significantly enhanced the degradation of TPH in contaminated soil after 90 days by 20.8% and in conjunction with L. corniculatus by 26.33% compared to the control. The soil enzymatic activity was more pronounced in TPH-contaminated soil treatments, and in most cases, the presence of L. corniculatus and inoculum led to a significantly higher soil enzymatic activity. The cultivation of L. corniculatus and the inoculum resulted in an increased concentration of inorganic P, NH4+, and water-soluble phenols in the soil, while no rise in NO3− was observed.