Unveiling the Potential of Oleic Acid as a Soil Amendment for TPH-Contaminated Soil: Implications for Soil Remediation and Plant Performance

Abstract

Background: The contamination of soil with total petroleum hydrocarbons (TPHs) poses significant challenges to soil health and plant productivity. Oleic acid (OA), a monounsaturated fatty acid, has shown promise as a soil amendment, with potential benefits for soil remediation and plant growth. Objectives: This study investigated the effects of OA on soil properties, rice plant growth, and its efficiency in reducing TPH levels in contaminated soils. Methods: TPH contamination adversely impacted soil properties by reducing pH, organic matter (OM), and nutrient availability. The addition of OA to TPH-contaminated soil was assessed for its ability to mitigate these negative effects and enhance soil quality. Key Findings: The incorporation of OA significantly improved soil properties by increasing pH, OM, and nutrient availability. Furthermore, OA supplementation facilitated substantial reductions in TPH levels over time, primarily through mechanisms such as emulsification, microbial degradation, solubilization, and enhanced microbial activity. The results highlight that OA’s effectiveness in degrading TPH is both concentration- and time-dependent, with prolonged incubation leading to better outcomes. Significance: These findings demonstrate OA’s potential as a sustainable and effective amendment for remediating TPH-contaminated soils, improving soil health, and supporting plant growth. Future research should explore OA’s application strategies across different soil types and its potential to remediate multiple pollutants, including heavy metals and polycyclic aromatic hydrocarbons.