Kinetic Study of Carbon Dioxide (CO2) Respiration Rate in Bioremediation of Soil Contaminated with Spent Motor Oil

Abstract

ABSTRACT This study was carried out to investigate the kinetics of CO2 generation from the bioremediation of soil contaminated with spent motor oil (SCSMO) in an aerobic fixed-bed bioreactor designed and fabricated using indigenous technology. Six contaminated soil samples with different compositions at the same contaminant strength were investigated under a controlled air flow rate of 10 L/h. Results obtained revealed that treatment option “6” (i.e., the biostimulation option) gave the best result, with 75% reduction in the initial oil and grease content (O&G) and CO2 generation of 6,242 mg/kg contaminated soil (CS). Therefore, the biostimulation option was chosen as the treatment technology and kinetic investigation was based on the treatment technology. Results of kinetic investigation of the treatment technology showed that the growth rate can be represented by the popular Monod equation and the kinetic parameters are μmax = 1.115 × 10−16 h−1; K O&G = 37,490.9 mg/kg; yield of CO2 = 42.59%; and yield of biomass = 57.41%. The rate equation and kinetic parameters can be used to design a bioreactor and monitor biodegradation reaction during bioremediation process.