Kinetic modelling and half-life study on bioremediation of diesel oil contaminated soil and water using nano remediation strategy

Abstract

The study described the kinetic modelling and half-life study on bioremediation of engine oil contaminated soil and water using nano - remediation strategy. In this study, bioremediation process was carried out in diesel oil hydrocarbon polluted water and soil using green nano scaled silver particles (AgNPs) which were synthesized from seed extract of Moringa oleifera under ambient conditions. The synthesis of silver nanoparticles was confirmed by systematic characterization using Fourier transform infrared spectroscopy, UV-spectroscopy, Xray diffraction analysis and Scanning electron microscopy. The degradation of diesel oil residue after each degradation time was measured spectrophotometrically. The result revealed that FT-IR spectra had O-H stretching vibration (carbohydrate group), a strong surface plasmon resonance at 400 nm peak, ultra-fine nature, and small crystalline size of 50 nm. The result showed that 5 mL concentrations of M. oleifera NPs had the highest degradative percentage of 94.26 % and 93.93 % after 60 days while 10 mL and 15 mL concentrations had the lowest percentage degradative efficiency values 85.93 % and 81.73 % after day 1 in diesel oil contaminated water and soil, respectively. The AgNPs application at different concentrations to waste diesel oil contaminated water and soil does not significantly (P > 0.05) accelerate the degradation of waste diesel oil. First - order kinetics and second - order kinetics both satisfactorily described the biodegradation of the diesel oil-based contaminants. The study has unveiled the kinetic mechanisms underlying the diesel oil nano - biodegradation process and therefore gives credence to the current research study.