The removal of toxic methyl ethyl ketone (MEK) is studied in a lab scale biofilter packed with mixture of coal and matured compost. The biofiltration operation is divided into 5 phases for a period of 60 days followed by shock loading conditions for three weeks. The maximum removal efficiency of 95% is achieved during phase 11 for an inlet concentration of 0.59 g m(-3), and 82-91% for the inlet concentration in the range of 0.45-1.23 g m(-3) of MEK during shock loads. The Michaelis-Menten kinetic constants obtained are 0.086 g m(-3) h(-1) and 0.577 g m(-3). The obtained experimental results are validated using Ottengraf van den Oever model for zero-order diffusion-controlled region to understand the mechanism of biofiltration. The critical inlet concentration of MEK, critical inlet load of MEK and biofilm thickness are estimated using the results obtained from model predictions. (C) 2009 Elsevier Ltd. All rights reserved,