Experimental study on shortcut simultaneous nitrogen removal in treating domestic sewage

To treat domestic sewage with high efficacy and low cost, the technology of shortcut simultaneous nitrogen removal was used with a new biofilm reactor. The influences on nitrogen removal effect by start-up procedure, nitrogen transformation characteristics and main factors (hydraulic retention time, dissolved oxygen, carbon-nitrogen ratio) were analyzed. The results indicate that: The reactor finished start-up of shortcut simultaneous nitrogen removal in 14 days of cultivation time after the biofilm cultured in the carrier. The ammonia nitrogen removal rate, simultaneous nitrification-denitrification rate and cumulative nitrite nitrogen rate respectively reached 91.3%, 82.7% and 63.4% in the last phase of start-up procedure. To remove ammonia nitrogen with the technology of shortcut simultaneous nitrogen removal efficiently and steadily, hydraulic retention time, dissolved oxygen, carbon-nitrogen ratio should be controlled in 3.56 hours, 1.5 mg/L and 5~8.