The kinetics of phenol degradation by free and immobilized cells of pseudomonas sp.

Abstract

The kinetics of phenol degradation by an immobilized-bacterial system was carried out in a packed reactor operating in a repeated batch culture. The phenol-degraders used, i.e., Pseudomonas sp., were locally isolated from water sample obtained from one residential wastewater treatment plant and soil sample from the wastewater discharge area of one oil-processing industry. The reactor was packed with either bioceramic or sponge as support material with bio-ceramic showing a higher ability to trap 1.8 times more bacterial cells than sponge, which is advantageous for phenol degradation. A continuous 24-hour cycle using influent flow rate of 2.5 mL min?¹, revealed that the bio-ceramic grown cells were capable to completely mineralized 1000 mg L?¹ of phenol in six changes of phenol solutions compared to 90% phenol degradation by the sponge-grown cells. Immobilized cells showed a phenol tolerance level of 2000 mg L?¹ compared to 1000 mg L?¹ for the suspended cells. Outcomes of this study offer useful guidelines in evaluating potential phenol degraders from the environment and in treating phenolic contaminants using packed reactor system.