Determination of mass transfer coefficients for a mixture of compost, sugarcane bagasse, and granulated activated carbon as packing medium in biofilter

Abstract

A laboratory-scale biofilter unit packed with a mixture of compost, sugarcane bagasse, and granulated activated carbon (GAC) in the ratio of 55:30:15 by weight was used for a biofiltration study of air stream containing benzene, toluene, ethylbenzene, and o-xylene (BTEX). The effect of superficial velocity on mass transfer coefficient for the packing was studied by maintaining gas flow rates of 3, 4, 5, 6, and 8 L min-1 for inlet concentrations of 0.1, 0.4, and 0.8 g m-3 for each of benzene, toluene, ethylbenzene, and o-xylene. The maximum elimination capacity was found to be 20.92, 22.72, 20.73, and 18.94 g m-3 h-1 for BTEX, respectively, for stated flow rates. Removal efficiency of BTEX decreased from 99% to 71% for increasing inlet concentration from 0.1 to 0.8 g m-3. Gas film mass transfer coefficient predicted by modified Onda's equation was within ±10% of the experimental values. © 2013 Taylor and Francis Group, LLC.