Biological treatment of wastewater contaminated with p-cresol using Pseudomonas putida immobilized in polyvinyl alcohol (PVA) gel

In this study, the biodegradation of simulated wastewater containing p-cresol has been carried out using Pseudomonas putida immobilized in PVA gel, in batch and continuous reactors. The effects of initial concentration, temperature, pH and PVA volume fraction on the biodegradation of p-cresol were evaluated in a batch SBBR. Continuous experiments were also carried out to study the effect of other operating parameters such as air flow rate and residence time on the biodegradation efficiency. The batch experimental results indicated that the biodegradation capabilities of P. putida are highly affected by temperature, pH and PVA vol.% and optimum performance were obtained at 35 °C, 8 and 40%, respectively. The biomass did not seem to be inhabited by high concentration of p-cresol and the biodegradation data fitted well the Monod non-inhibitory Model. The kinetics data obtained from the Monod model were utilized in modeling the continuous biodegradation process and gave very good agreement with experimental results.