Study On Biotrickling Filters For H₂S Removal And Engineering Design

Environmental policy has focused on abatement of odors emissions fromwastewater treatment plants, and new Chinese H2S emission limits have beenestablished. The performance of three pilot-scale immobilized cell biotrickling filters(BTFs) packed with different combination patterns of bamboo charcoal and ceramsitewere investigated for hydrogen sulfide removal. Extensive tests to determine removalcharacteristics, pressure drops, metabolic products analysis, and removal kinetics ofthe BTF were performed.The experiments were operated in continuous mode at low loading rates varyingfrom0.59to5.00g H2S m-3h-1with an empty bed retention time (EBRT) of25s. Theremoval efficiency (RE) for each BTF was larger than98%at the steady-state periodand high standards of exhaust gas were obtained. Both bamboo charcoal andceramsite demonstrated good performance as packing materials in BTFs for theremoval of H2S. The results of this study could be used as a guide for the furtherdesign and operation of industrial-scale systems. In addition, multi-layer BTF had aslight advantage over perfect mixing BTF for the removal of H2S. An impressiveresult was achieved that more than97%of H2S was eliminated by10%of packingmaterials at the odor inlet of the BTF. The modified Michaelis-Menten equation wasadopted to describe the characteristics of BTF, in which the equation parameters Ksand Vmfor BTF3were calculated to be3.636ppmv and4.27g H2S m-3h-1,respectively.According to the pilot-scale experiment study and engineering experience, anengineering design of a wastewater treatment plant with biotrickling filter technologywas done, basic process flow and engineering parameters was introduced in thisstudy.