Mohammad Hassan Fazaelipoor - Biotechnology Group,Chemical Engineering Department,Tarbiat modares University,Tehran,Iran
Seyed Abbas Shojaosadati - Biotechnology Group,Chemical Engineering Department,Tarbiat modares University,Tehran,Iran
Ebrahim Vasheghani Farahani - Biotechnology Group,Chemical Engineering Department,Tarbiat modares University,Tehran,Iran
Jafar Towfighi Darian - Biotechnology Group,Chemical Engineering Department,Tarbiat modares University,Tehran,Iran

Two equal size perlite based biofilters were used to investigate the effect of adding silicone oil to the bed of a biofilter for removal of n-hexane from contaminated air. Bed particles of the one of the biofilters partially coated with silicone oil. An n-hexane degrading bacterial culture was used as inoculum in both biofilters. The biofilters operated in parallel under the same conditions for 70 days. Results showed that the silicone oil added biofilter performed better than the other consistently during the investigation period .The maximum elimination capacity for silicone oil added biofilter was 167 gm-3h-1 compared to 114.9 gm-3h-1 for the biofilter without silicone oil. Response of the biofilters to step and pulse change at inlet concentration was also investigated. A new steady state was established within several minutes after a change at inlet cocentration. When the inlet concentration decreased suddenly ,the outlet concentration of of the silicone oil added biofilter was higher than the other for a short period of time due to desorption phenomenon.

Biofiltration, n-Hexane, Silicone oil