Development and Performance Evaluation of Indigenous Bioresource-Based Solid Biostimulant Technology for Petroleum Hydrocarbon Pollution Remediation in Bayelsa

Abstract

Petroleum hydrocarbon contamination remains a significant environmental challenge in the Niger Delta, particularly in Bayelsa State, where recurrent oil spills, artisanal refining activities, and other anthropogenic disturbances have severely degraded soil quality and ecosystem health. In this study, an indigenous bioresource-based solid biostimulant for the remediation of hydrocarbon-contaminated soils was developed and evaluated. The biostimulant was formulated from locally sourced materials, including blended invasive aquatic plant biomass, and enriched with plant-derived biopolymers to enhance nutrient availability, improve soil structure, and stimulate microbial activity. The formulated product was characterized for its physicochemical properties and applied to hydrocarbon-contaminated soils collected from artisanal refining sites with Total Petroleum Hydrocarbon (TPH) concentrations ranging from 7,000 to 15,000 mg/kg. Remediation experiments were conducted under controlled conditions, and treatment performance was assessed through TPH quantification and gas chromatographic analysis of hydrocarbon fractions. The results demonstrated that the biostimulant significantly enhanced hydrocarbon degradation within three weeks compared with untreated controls, indicating effective stimulation of indigenous microbial communities. Petroleum hydrocarbon concentrations decreased substantially across all measured fractions, with most hydrocarbon homologous series exhibiting reductions exceeding 80% and a maximum reduction of 99.25%. TPH reduction ranged from 48% to 82%, corresponding to an average degradation efficiency of approximately 67%. Although residual TPH concentrations (3,709 mg/kg) remained above the target background threshold of 50 mg/kg, they were reduced below the intervention threshold of 5,000 mg/kg. These findings demonstrate the strong potential of locally derived, environmentally friendly biostimulant technologies as cost-effective and sustainable solutions for the remediation of petroleum hydrocarbon-contaminated soils in the Niger Delta.