Performance Drivers for Diesel Degradation in Multiphase Bioreactors by Microbial Consortia Isolated from Polluted Environments

Hydrocarbon removal from water by microbial consortia is of great importance for mitigating environmental pollution. This study examined physical and biological parameters influencing diesel (DSL) biodegradation by microbial consortia, aiming to identify key factors for efficient degradation in multiphase bioreactors. A modified mathematical model was parametrized using microbial kinetics; hydrocarbon uptake mechanisms (emulsification and direct interfacial uptake); and data sets from experiments on oil-degrading consortia isolated from marine sediments, sinkholes, and swamps. Tessier kinetics were incorporated into this model, and linear regression was used for validation (with 0.82 < R2 < 0.99, α = 0.05, and p-values > 0.01). Local sensitivity analysis identified the most influential parameters for DSL biodegradation. Microbial kinetics were primarily driven by the maximum specific growth rate, half-saturation constant, inhibition constant, and yields. Hydrocarbon uptake mechanisms were significantly influenced by Sauter’s mean diameter and hydrophobicity coefficient, linked to bioreactor hydrodynamics and the characteristics of bacterial strains, respectively. These findings provide insights into optimizing DSL biodegradation in multiphase bioreactors.