Biopile Composting of Petroleum-Contaminated Soil Enhanced with Nutrient Amendment and Biosurfactant Addition

Abstract

Petroleum-contaminated soil generated from industrial spills, refinery operations, and transportation activities poses serious environmental and ecological risks due to the persistence and toxicity of hydrocarbon pollutants. This study investigates the effectiveness of biopile composting enhanced with nutrient amendment and biosurfactant addition for the remediation of petroleum-contaminated soil under controlled aerobic conditions. The research focuses on improving microbial degradation activity and accelerating hydrocarbon removal through optimized biostimulation strategies. Experimental analyses were conducted to evaluate the influence of nutrient supplementation, moisture content, aeration rate, temperature, and biosurfactant concentration on biodegradation efficiency and soil quality improvement. The addition of nutrient amendments promoted microbial growth by maintaining an appropriate carbon-to-nitrogen-to-phosphorus ratio, while biosurfactants enhanced hydrocarbon bioavailability through increased pollutant solubilization and mass transfer. Results demonstrated significant reduction in total petroleum hydrocarbon concentration with improved degradation rates compared to conventional composting methods. The biopile system maintained stable thermophilic and mesophilic conditions that supported active microbial metabolism and effective contaminant breakdown over the treatment period. Kinetic analysis confirmed enhanced biodegradation performance due to synergistic interaction between nutrient enrichment and biosurfactant-assisted pollutant mobilization. Furthermore, the remediation process improved soil physicochemical properties and reduced environmental toxicity, indicating the suitability of the treated soil for potential reuse applications. The study highlights the potential of integrated biopile composting as a cost-effective and environmentally sustainable remediation technology for large-scale treatment of hydrocarbon-contaminated soils, supporting efficient waste management and ecological restoration practices.