ACCELERATED BIODEGREDABILITY OF CHLORPYRIFOS (PESTICIDE) RESIDUE IN CONTAMINATED SAVANNAH SOIL WITH MORINGA OLEIFERA LEAF POWDER

Abstract

The residue of organophosphate pesticides (chlorpyrifos) present in the sandy-loam soil of the Guinea Savannah Nigeria is a threat to the soil ecosystem health. This study evaluated the efficacy of Moringa oleifera leaf powder (MOLP) as a bio-stimulant for the remediation of chlorpyrifoscontaminated farmland in Zango, Adavi, Kogi State, Nigeria. Samples of the soil were treated with varying concentrations of MOLP low dose, 5% and high dose, 10% over 90 days study period. High-performance liquid chromatography (HPLC) analysis revealed that the higher-dose MOLP treatment achieved 81% removal efficiency, following first-order kinetics with a significantly reduced half-life of unamended controls. The amendment stimulated a "microbial bloom," increasing from 1.2 x 106, to 5.2 x 106 cfu/g. These findings suggest that Moringa leaf amendment served dual functions: detoxifying pesticide residues and improving soil microbial population. The study concludes that MOLP is a viable, sustainable alternative to conventional chemical oxidation, achieving effective decontamination without compromising soil ecological integrity.