Introduction & Objective: Biological treatment is a new established technology for the air pollutants. This technology can be an alternative for physical and chemical treatment methods. Among bioreators, the Bioactive Foamed Emulsion Reactor (BFER) is a new alternative that has not the problems of the conventional ones. In this reactor bed clogging in the conventional bioreactor was resolved by bioactive foam as a substitute of packing bed. The pollutant absorption has been increased using biocompatible organic phase in liquid .This reactor can be used for higher inlet toluene concentration. The objective of this study was designing and optimizing the operational parameters of BFER for toluene treatment.

Materials & Methods: In the first step of this experimental-analytic study, the toluene degradation microorganisms were identified, extracted and concentrated for injection to bioreactor. Then the effect of several parameters such as Kind and concentration of organic phase, and residence time oxygen content on bioreactor performance were studied and the optimum conditions were selected for continuous operation. The continuous operation of bioreactor was monitored at the optimum conditions.

Results: Experimental results showed that the residence time of 15s, oxygen content of 40%, and the 4 % (v/v) n-hexadecane as organic phase were the optimum conditions. The average elimination capacity (EC) and removal efficiency of bioreactor were 231.68 g/m3h and 88.44% respectively for the inlet concentration about of 1 g/m3. The statistical developed model predicted that the maximum EC of this reactor could reach to 426.21 g/m3h.

Conclusion: Since the elimination capacity of this reactor is several times more than the other bioreactors, it has the potential to be applied instead of biofilters and biotrickling filters