Two　pilot-scale　bio-trickling　filters　(BTFs)　with　counter-current　and　cross-current　flow　modes　were　constructed,　and　their　performance　tested,　for　purifying　chemical　fibre　waste　gas　containing　H2S,　NH3　and　VOCs　with　a　maximum　gas　flow　rate　of　1008　m(3)　h　(1).　The　counter-current　type　of　BTF　presented　with　superior　biodegradation　results　compared　to　the　cross-current　type:　it　could　start　up　quickly,　tolerated　high　transient　shock　loadings,　and　possessed　an　average　contaminant　removal　efficiency　higher　than　90%　with　an　empty　bed　residence　time　of　59　s.　The　contaminant　removal　efficiency　could　be　increased　by　50%　during　winter　due　to　the　addition　of　pipeline　insulation.　The　abundance　and　diversity　from　microorganism　analysis　showed　that　Dyella,　Bacillus,　Candidimonas,　Pandoraea　and　Thiomonas　were　the　main　bacterial　strains　forming　the　community　treating　the　pollutants.　The　counter-current　type　BTF　functioned　most　effectively　and　is　proposed　for　practical　application.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.