Time required for achieving more than 90.0% removals for BTEX are 6, 7, 9 and 10 days, respectively. The results showed that the degradation time of toluene was the lowest followed by benzene, ethyl benzene and o-xylene. (Qi et al., 2005) reported similar results for the degradation of mixture MEK, methyl propyl ketone, toluene and n-butyl acetate in biofilter (Qi et al., 2005).