Nitrogen Removal Using ANAMMOX and Denitrification for Treatment of Municipal Sewage

In this study, an Anaerobic Baffled Reactor ( ABR) was constructed. The ANAMMOX process was successfully started up using this reactor within 45 days under the following condition: 27 degrees C, pH of 8, HRT of 10 h, and the influent NO2(-) -N/NH4(+) -N was 1.32. At the stable phase, the average TN removal percentages reached 83% and the ΔNH4(+) -N: ΔNO2(-) -N: ΔNO3(-) -N was 1 : 1. 31 : 0.27. In the process of treating municipal sewage, there was inevitably a certain amount of organic carbon in the influent. Organic carbon had no obvious effect on the ANAMMOX process at C/N of 0.5; Nitrogen removal was improved, and the average total nitrogen (TN, including ammonia, nitrite and nitrate nitrogen) removal efficiency of 93% was obtained at C/N of 1. However, at C/N of 2, the TN removal performance reduced due to the suppression of ANAMMOX by organic carbon; the ANAMMOX bacteria could recover their activity in a short period of time by reducing the influent COD concentration. In this work, the performance of the ANAMMOX-denitrification process in the treatment of municipal sewage was investigated, which proved the suitability of ABR-denitrification reactor in treating municipal sewage with low ammonia nitrogen concentration, with an effluent TN concentration of 7.5 mg x L(-1), and the average TN removal percentages reaching 86%.