REMEDIATION OF CRUDE-OIL CONTAMINATED SOIL USING FUNCTIONALIZED BIOCHAR PRODUCED FROM BLENDS OF PALM KERNEL AND UNRIPE PLANTAIN PEELS

In this study, the efficacy and performance of functionalized biochar produced from a blend of palm kernel shell (PKS) and green plantain peels (PP) were evaluated for the removal of BTEX compounds from contaminated crude oil soil. The biochar was prepared, characterised, and evaluated under varying dosages (30g, 40g, 50g and 60 g), pH (2,5 and 10), and initial contaminant concentration (5000mg/kg, 8,000mg/kg, 10,000mg/kg, and 12,000 mg/kg). Physicochemical soil characterisation of 7.45 pH, 36.44% moisture content, and 38.76% total organic carbon was favourable for adsorption and biodegradation. GC–MS analysis revealed that the dosage increased from 30 g to 60 g augmented the removal of toluene from 65.20% to 95.75% and ethylbenzene from 67.03% to 81.30%, while the removal of benzene was slightly enhanced from 22.88% to 49.63%. Maximum removal was achieved at pH 10 with average efficiencies of over 80% for the heavier fractions of BTEX. The results reaffirm that PKS–PP biochar had a maximum removal efficiency of 95.8%, reaffirming it as a low-cost, eco-friendly sorbent for hydrocarbon-contaminated soil remediation. The findings also suggest a dual adsorption–biodegradation mechanism, where biochar not only immobilises BTEX compounds on its surface but also promotes microbial activity that enhances their degradation, offering a synergistic and sustainable remediation pathway for contaminated soils.