Biodegradation of Toluene using Biofilms in a Bubble Column Bioreactor

Yong-Bok Choi, Jang-Young Lee and Hak-Sung Kim

Biodegradation of toluene in liquid effluent stream was carried out using biofilms of Pseudommonas putida formed on celite particles in the bubble column bioreactor. Silicon rubber tubing was installed at the bottom of the bioreactor and liquid toluene was circulated within the tubing. Toluene diffused out of the tube wall and was transffered into the culture broth where degradation by biofilms occured. The operating variables affecting the formation of biofilms on celite particles were investigated in the bubble column bioreactor, and it was found that formation of biofilm is favored by high dilution rate and supply rate of carbon sourcewhich stinulate the growth of initially attached cells. Continous biodegradation of toluene using biofilms was stabley conducted in the bioreactor for more than one month without any significant fluctuation, showing a removal efficiency higher than 95% at the toluene transfer rate og 1.2g/L/h.