A new type poly(vinyl alcohol) (PVA)/peat/bamboo charcoal (BC)/KNO3 composite bead was prepared, which has a diameter of 2.4-6.0 mm and a density of 1.133 g/cm(3) and is a porous spherical particle. The biochemical kinetic behaviors of n-butyl acetate in PVA/peat/BC/KNO3 spherical composite bead biofilter (BC biofilter) and PVA/peat/granular activated carbon (GAC)/KNO3 spherical composite bead biofilter (GAC biofilter) were investigated. The values of half-saturation constant K-s for BC biofilter and GAC biofilter were 27.89 and 27.95 ppm, respectively. The values of maximum reaction rate V-m for BC biofilter and GAC biofilter were 13.49 and 13.65 ppm/s, respectively. Zero-order kinetic with the diffusion limitation was regarded as the most adequate biochemical reaction model for the two biofilters. The microbial growth rate and biochemical reaction rate for two biofilters were inhibited at higher inlet concentration, and the degree of inhibitive effect was more pronounced in the inlet concentration range of 100-800 ppm. The biochemical kinetic behaviors of the two biofilters were similar. The maximum elimination capacity of BC biofilter and GAC biofilter were 111.65 and 122.67 g C/h m(3) bed volume, respectively. The PVA/peat/BC/KNO3 composite bead was suitable as a biofilter material. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1782-1787, 2011