Abstract
Remediation of oil-polluted soil is challenging due to hydrophobic hydrocarbons that impair hydraulic conductivity, which governs water flow, runoff, and contaminant transport. This study examined and optimized an integrated electrobiokinetic remediation system involving phytoremediation, biodegradation, and electrokinetics in crude oil-contaminated clay loam soil planted with bermuda grass ( Cynodon dactylon ) at varying crude oil levels of 1.5%, 3%, and 4.5%, electric potential gradients of 0, 1.5, and 3 V cm -1 , biological supplements of 0%, 3% Pseudomonas fluorescens , and 3% algal-bacterial consortium ( Chlorella + Pseudomonas fluorescens ), and soil moisture regimes of 60%, 80%, and 100% of field capacity. Response Surface Methodology modeled effects on static/dynamic water repellency and saturated hydraulic conductivity. The electro-biokinetic approach significantly reduced water repellency and increased hydraulic conductivity. Optimal results were observed in Run 22 (1.5% oil, 1.5 V cm -1 , 3% algal-bacterial consortium), reducing dynamic repellency to 0.255 s and static repellency to 36.77°, and increasing hydraulic conductivity to 54.95 cm day -1 . The algal-bacterial consortium (dried Chlorella biomass + P. fluorescens ) demonstrated the most significant improvement. High model predictive power (R 2 = 0.9243, 0.9171, 0.9469) supports this synergistic method for improving hydraulic and hydrophobicity balance in petroleum-affected soils. This highlights the potential of the applied integrated strategy as a promising approach for improving the hydraulic functioning of petroleum-contaminated soils. However, further field-scale validation under different environmental conditions should be considered.