[Removal of BTEX by a biotrickling filter and analysis of corresponding bacterial communities]

The pre-acclimated microbial consortium and the activated sludge were used as start inoculums of a bench-scale biotrickling filter (BTF). The performance of the biotrickling filter on the removal of BTEX mixture was evaluated, and the changes in the bacterial community structure of the BTF were analyzed by PCR-DGGE technique. The results showed that the BTF could be acclimated within a short time, the biomass that adhered to the surface of packing materials increased rapidly from 5.7 mg x g(-1) at 10th day to 112 mg x g(-1) at 30th day. BTF could simultaneously remove all components of the BTEX mixture efficiently. The maximum removal capacity of the BTF was 216.6 g x (m3 x h)(-1), which was achieved with an inlet loading rate of 269.7 g x (m3 x h)(-1) and an empty bed retention time (EBRT) of 39 s. DGGE analysis indicated that the dominant microorganisms may be derived from the pre-acclimated microbial consortiums rather than the activated sludge. Although the bacterial community changed with run time, the spatial distribution was very uniform.