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.

KEYWORDS:

• bagasse
• biofiltration
• compost
• granulated activated carbon
• mass transfer coefficient