Evaluation of Temperature Effects on Biokinetic Functional Parameters of Petroleum Hydrocarbon Degradation in Freshwater Environment

This study investigated the influence of temperature on the biokinetic functional parameters governing total petroleum hydrocarbon (TPH) degradation in freshwater environments. The research employed the Monod kinetic model to describe the relationship between substrate concentration and degradation rate, while Lineweaver–Burk analysis was used to evaluate the maximum specific degradation rate and substrate affinity-related kinetic constant. Temperature-dependent kinetic behaviour was examined at 15, 30, 45, 60 and 75 °C. The reciprocal relationship between degradation velocity and substrate concentration was evaluated using linear regression equations obtained from the corresponding Lineweaver–Burk plots. The estimated maximum velocity parameters (Vmax) varied considerably with temperature, with reported values of 285.71, 333.33, 1666.67, 500, 500, 50,000 and 166.67 (ppm/hr)⁻¹ at 15, 30, 45, 60 and 75 °C, respectively. The corresponding reported kinetic constants also exhibited substantial variations, indicating a temperature-dependent response of the degradation system. In addition, modified sedimentation relationships based on Stokes' and Newton's laws were formulated to incorporate oil-particle characteristics into the analysis of hydrocarbon behaviour in water. The findings demonstrate that temperature significantly influences the estimated biokinetic parameters and the mathematical description of TPH degradation in freshwater. The study provides a modelling framework for understanding hydrocarbon degradation behaviour and supporting the engineering assessment of petroleum-contaminated aquatic environments. However, further experimental validation is necessary to establish the biological significance of the unusually high-temperature kinetic estimates and verify the consistency of the reported parameters.