[Start-up and Operation of Biofilter Coupled Nitrification and CANON for the Removal of Iron, Manganese and Ammonia Nitrogen].

A pilot-scale bio-filter coupled nitrification and CANON was started up to remove iron, manganese and ammonia nitrogen from groundwater in a plant, and the main removal route of ammonia nitrogen was analyzed. The experiment showed that the bio-filter could be started up successfully and achieved stable operation after 164 days of culture development. The value of △NH4+-N/△NO3--N was 1.49, and the oxidation and removal of Fe(Ⅱ), Mn(Ⅱ), and NH4+-N were (9.87±1.17), (2.25±0.06), and (1.51±0.06) mg·L-1, respectively. The calculation based on the quantitative relationship between nitrogen conservation and dissolved oxygen (DO) measurement indicated that the contribution of CANON to NH4+-N removal was 33.48%-38.87%, and the average ratio of ammonia nitrogen removal amount to DO was 1:3.79-1:3.94. The removal ratio of ammonia nitrogen was lower with lower temperature.