Removal of gaseous chlorobenzene (CB) by a biotrickling filter (BTF) filled with modified ceramics and multi-surface hollow balls during gas-liquid mass transfer at the steady state was by microbial degradation rather than dissolution in the spray liquid or emission into the atmosphere. The BTF was flexible and resistant to the acid environment of the spray liquid, with the caveat that the spray liquid should be replaced once every 6-7 days. The BTF, loaded with Lysinibacillus fusiformis, performed well for purification of high-loading CB gas. The maximum CB gas inlet loading rate, 103 g m(-3) h(-1), CB elimination capacity, 97 g m(-3) h(-1), and CB removal efficiency, 97.7 %, were reached at a spray liquid flow rate of 27.6 ml min(-1), an initial CB concentration of up to 1,300 mg m(-3), and an empty bed retention time of more than 45 s.