Research on Aerated Nitrification and Nitrogen Loss in IAL-CHS

The study purpose was to study the nitrification and nitrogen removal performance in IAL-CHS by lab-scale experimental bulk.the removal rate of ammonium (NH₄ ⁺-N) was enhanced from 5.00% to 85.70% within 24 h by inoculated nitrification sludge. Removal performance of NH₄ ⁺-N and TN were evaluated in IAL-CHS, The results showed that the average removal rate of NH₄ ⁺-N was 56.2%, 39.0% and 25.8% under NH₄ ⁺-N loading of 0.77, 0.83, and 0.62 kg/(m³ d) when hydraulic retention time (HRT) were set at 2 h, 1 h, and 2/3 h, respectively. The removal rate of total nitrogen (TN) was 50.03% as HRT was 1 h. Furthermore, nitrite (NO₂ ^-) and nitrate (NO₃ ^-) concentration in influent and effluent were investigated for know the mechanism of nitrogen loss in IAL-CHS. The results showed that NO₂ ^- and NO₃ ^- concentrations in influent and effluent were little, which might indicated that nitrogen loss by gaseous nitrogen (N₂ or N₂O) from IAL-CHS to atmosphere. It was believed that the special-designed structural feature of ceramic honeycomb support and operational mode are the principal causes for nitrogen loss in IAL-CHS. Nitrifying bacteria and denitrifying bacteria were observed simultaneously in IAL-CHS.