Performance of biotrickling filters packed with structured or cubic polyurethane sponges for VOC removal

摘要

Two identical bench-scale biotrickling filters (BTFs),BTF 1 and BTF 2,were evaluated for toluene removal at various gas empty bed contact times (EBCTs) and organic loadings.BTF 1 and BTF 2 were packed with structured and cubic synthetic polyurethane sponges,respectively.At a constant toluene loading of 16 g/(m 3 ·hr),toluene removal efficiencies decreased from 98.8% to 64.3% for BTF 1 and from 98.4% to 74.1% for BTF 2 as gas EBCT decreased from 30 to 5 sec.When the toluene loading increased from 35 to 140 g/(m 3 ·hr) at a gas EBCT of 30 sec,the removal efficiencies decreased from 99.1% to 77.4% for BTF 1 and from 99.0% to 81.5% for BTF 2.The pressure drop for both BTFs increased with increased air flow rate,and did not significantly vary while the toluene loading was increased under similar operation conditions.BTF 1 and BTF 2 could start up successfully within 19 and 27 days,respectively,when packed with fresh sponge media,and the performances could be restored in 3-7 days after biomass was removed and wasted from the media.BTF 2 displayed higher removal efficiency even under shorter EBCT or higher loading rate than BTF1 when other operation conditions were similar,while it showed lower pressure drop than BTF 1 during the whole period of operation.These results demonstrated that both BTFs could treat waste gas containing toluene effectively.