Comparison of the NH3 Removal Characteristics by Trickle-Bed Air Biofilter Packed with Four Inorganic Packing Materials

Four inorganic packing materials were evaluated in terms of their availability as a packing material in trickle-bed air biofilter (TBAB) of biological NH₃ removal characteristics. The nitrification rate is in the order of zeolite > active carbon > ceramic pellets > multi-face ball. The highest nitrification rate for zeolite, polypropylene multi-face ball, ceramic pellets and active carbon were 275, 136, 233 and 261mg/(L.d). Visible biomass growth was obtained within 15 days for zeolite, pellets and active carbon, and within 20 days for multi-face balls. During this experiment, the pressure drops in TBABs with zeolite, ceramic pellets, and active carbon were around 3, 2.5 and 4.6 mmH₂O, respectively. Zeolite is the best selection as packing material for ammonia removal, and multi-face ball is not a better choice as packing material to remove ammonia.