Biodegradation kinetics of 2,6-dihydroxybenzoic acid and peptone mixture by acclimated microbial culture at low sludge age

This study evaluated the kinetics of 2,6-dihydroxybenozic acid and peptone biodegradation at low sludge age by acclimated culture under aerobic conditions. A laboratory-scale sequencing batch reactor was set and fed with peptone mixture. The system was operated at steady-state at a sludge age of 2 days. In order to assess biodegradation kinetics of 2,6-dihydroxybenozic acid and its impact on peptone utilization, a mixture of 2,6-dihydroxybenzoic acid and peptone was fed to mixed culture. After a period of four days, the system became acclimated to simultaneously remove both 2,6-dihydroxybenzoic acid and peptone mixture. A mechanistic model was developed involving model components and kinetic parameters for both substrates. This model was calibrated with related experimental data such as oxygen uptake rate and COD. Biodegradation characteristics and kinetics of peptone and 2,6- dihydroxybenzoic acid was estimated. The evaluation of calibrated model indicated that a group of microorganisms adjusted their enzymatic tools for the utilization of 2,6-dihydroxybenzoic acid resulting in dual microbial community development at low sludge age.