Numerical Simulation of Plant–microbial Remediation for Petroleum-polluted Soil

This paper presents a numerical analysis of the migration and transformation mechanism of petroleum hydrocarbons (PHs) pollutants in soil. The mathematical model of the solute migration and plant–microbial remediation for PH polluted soil was established. The model was verified by field experimental data. Then, the software Hydrus-1D was employed to simulate the processes of diffusion, adsorption, desorption, microbial degradation, and plant adsorption of PHs in the soil–water system. The process of plant–microbial remediation for PH-contaminated soil was also simulated. The space-time change of PHs in soil was obtained, and the fate and remediation efficiency of PHs in soil were revealed in different remediation conditions. The results indicated that the Hydrus-1D model can adequately simulate the process of plant–microbial remediation. Plant–microbial remediation appears to be more efficient than the application of bacteria or Suaeda salsa. The majority of PH pollutants are degraded in the upper soil levels. For long-chain petro-alkane-contaminated soil, plant–microbial remediation is a more efficient method. A suitable moisture level in soil is important for improving the bioremediation effect of plant–microbial remediation technology.