The　performance　of　lab-　and　pilot-scale　bio-trickling　filters　(BTFs)　for　the　treatment　of　emissions　from　a　chemical　fibre　wastewater　treatment　plant　was　investigated.　These　systems　were　installed　mainly　to　demonstrate　the　effectiveness　of　bio-trickling　technologies　in　purifying　exhaust　gases　containing　different　kinds　of　volatile　organic　compounds　(VOCs).　Results　showed　that　12　days　more　were　necessary　for　the　pilot-scale　BTF　to　start　up　successfully　than　the　lab-scale　one.　Both　the　lab-　and　pilot-scale　BTFs　exhibited　contaminant　removal　efficiency　higher　than　90%　at　an　empty　bed　residence　time　of　59　s,　corresponding　to　gas　flow　of　0.2　m(3)　h(-1)　and　550　m(3)　h(-1),　respectively.　The　reduction　of　the　microelement　in　the　nutrient　solution　had　little　effect　on　the　performance　of　the　pilot-scale　BTF.　The　abundance　and　diversity　of　the　microorganism　analysis　showed　that　the　diversity　of　the　contaminants　had　a　significant　influence　on　the　microorganism　distribution　in　the　BTF.　Economic　feasibility　study　showed　that　BTF　might　be　an　efficient　solution　for　VOCs　control　with　a　lower　cost　than　adsorption　technology　and　regenerative　catalytic　oxidation.