BIODEGRADATION AND KINETIC STUDIES OF GROUNDWATER CONTAMINATED WITH DOMESTIC PURPOSE KEROSENE USING MICROORGANISMS FROM AGRICULTURAL WASTE

Abstract

This study investigated the microbial degradation and kinetic study of groundwater contaminated with domestic purpose kerosene (DPK) by mixed-culture of microorganisms at ambient temperature (28-32°C). The results obtained showed that the microorganisms; total heterotrophic bacteria (THB), total hydrocarbon utilizing bacteria (THUB) and total fungi (TF) had positive response in utilizing total petroleum hydrocarbon (TPH) as domestic purpose kerosene. The order of hydrocarbon utilization was: THUB >TF >THB with mean growth rate constants of 3.96x10⁻³ hour⁻¹, 1.98x10⁻³ hour⁻¹ and 1.48x10⁻³ hour⁻¹ in that order. A total of ten bacterial isolates were recovered from the total viable count (TVC) plate. Six of these were hydrocarbon degraders. Four (4) fungal species were recovered. The control microcosm showed a reduction in TPH by 2.5% probably due to activities of microbes initially present in the groundwater sample or evaporation, as experiments were carried out in open - system to mimic natural environmental conditions. The degradation followed pseudo-first order kinetics with rate constant of 1x10⁻² mg⁻¹ Lhr⁻¹ at room temperature. In conclusion, the native microorganisms from the agricultural waste of poultry, piggery and cow had the capability of degrading petroleum hydrocarbons in areas where oil spillages occur.