Optimization of the Biodegradation of Aliphatic, Aromatic, and UCM Hydrocarbons from Light Crude Oil in Marine Sediment Using Response Surface Methodology (RSM).

This study describes the optimization of the biodegradation of total aliphatic (tAHCs), total aromatic (tPAHs), and unresolved complex mixture (UCM) hydrocarbons from light crude oil in marine sediment. The response surface methodology (RSM), with a Box-Behnken design, was used to optimize the hydrocarbon fraction degradation, reported as degradation efficiency (E (%)), using four independent variables (inoculum, dispersant, light oil concentration, and carbon/nitrogen ratio), all at three levels. Analysis of variance (ANOVA) showed R2 values of 0.976, 0.974, and 0.975 for tAHCs, tPAHs, and UCM, respectively. All fractions exhibited a statistically significant effect (P < 0.05) in the second-order quadratic regression model for degradation. According to the models, the optimal degradation prediction was: 81.03% for tAHCs, 85.96% for tPAHs, and 92.86% for UCM. This work highlights the possibility of carrying out efficient biodegradation, of more than 80%, through an optimization process using different light oil concentrations, opening up possibilities of multiple response optimization.