Oxidative Remediation of Petroleum-Contaminated Soil in IduEkpeye Community, Rivers State, Nigeria

Abstract

This study evaluated the remediation potential of hydrogen peroxide (H₂O₂) and a combination of hydrogen peroxide with sodium persulfate (H₂O₂/Na₂S₂O₈) on crude oil-contaminated soils in Idu Ekpeye community, Ahoada West Local Government Area, Rivers State, Nigeria. Soils were impacted by artisanal refining and pipeline leaks, leading to high concentrations of Total Petroleum Hydrocarbons (TPH) and Total Hydrocarbon Content (THC). The remediation efficiency was assessed over 7 and 28 days for various oxidant concentrations (10%, 20%, and 30%). Results showed a clear dose-dependent and time-dependent decline in both TPH and THC levels, with higher oxidant concentrations and longer treatment durations achieving more significant remediation. In topsoil samples, 30% H₂O₂/Na₂S₂O₈ achieved up to 98.28% THC reduction and 99.84% TPH reduction by day 28. Subsoil samples showed similar trends, with maximum removal rates of 87.23% for THC and 99.25% for TPH. The combined oxidant system outperformed individual H₂O₂ treatments across all parameters. Physicochemical assessments before treatment revealed acidic soil pH, low nutrient levels, and elevated organic content, underscoring the need for restoration of both chemical balance and ecological integrity. The study concludes that advanced oxidation processes using hydrogen peroxide and sodium persulfate are promising for sustainable remediation of hydrocarbon-impacted soils in the Niger Delta.