Removal of High Concentration of Ammonia Gas in a Hybrid Biofilter

A new biofiltration technique based on biofilter and trickle-bed air biofilter (TBAB) was introduced to remove high concentration of ammonia gas. The start-up of the hybrid biofilter was studied, and the hybrid biofilter performance of ammonia removal under different conditions, such as air flow rates and inlet ammonia concentrations are varied, was evaluated. A visible biomass growth was obtained within 15 days. During the operation, the removal efficiency (RE) did not show a distinct difference between gas flow rate of 0.3 m³/h and of 0.9 m³/h. But in fact air flow rate had effect on biological removal efficiency. When ammonia loading rate was kept at 25 gN/m³.h and air flow rate was kept at 0.7 m3/ h, the maximum elimination capacity (EC) was 56 gN/m³.h. The biofilm was examined microscopically under different ammonia loading rates to determine the potential indicator value of protozoa and metozoa for control of biofilterI.