The ZABOCS bio-trickling filter (BTF) system is designed to remove odors from large pump stations and wastewater treatment plant operations. Systems may be designed to treat up to 15,000 cfm (25,000 cu m/h) of odorous air per tower and to handle very high H2S concentrations (greater than 500 ppm) with better than 99% removal. The ZABOCS BTF system uses random packed polyurethane foam cubes as the support for biomass growth.