[Lab-scale SNAD Process in Wastewater Treatment Plant]

Outside the municipal waste water treatment plant(WWTP) which located in Mentougou District, Beijing, the effluent of the anoxic/oxic(A/O) phosphorus removal process served as the substrate to operate a completely autotrophic nitrogen removal over nitrite(CANON) filter reactor.. After the reactor was successfully activated, glucose was added to the influent as the organic carbon source. The simultaneous partial nitrification, anaerobic ammonium oxidation (ANAMMOX), and denitrification (SNAD) process was started to study the effect of SNAD filter on sewage treatment. The results showed that from 119 d to 128 d, the ammonia removal rate of the CANON process was more than 95%, and the maximum total nitrogen concentration in the effluent was 13.0 mg·L^-1. Total nitrogen concentration surpassed the 1A level of the Integrated Discharge Standard of Water Pollutants applied in Beijing City. The SNAD process was started by adding glucose to the influent at 129 d. The total nitrogen removal rate of this process was about 85% at 133-187 d, and the total nitrogen concentration in the effluent was 5.5-7.3 mg·L^-1. The filter plugged up at 195 d, and backwash was utilized at 196 d. During the subsequent 30 d, the total nitrogen removal rate of the reactor was greater than 85%, and the total nitrogen concentration in the effluent remained at 6.2-7.2 mg·L^-1. Compared with the CANON process, the SNAD process improved the total nitrogen removal rate and reduced the total nitrogen concentration of the effluent by 6 mg·L^-1. The ammonia and total nitrogen concentrations in effluent satisfied the 1A level of the Integrated Discharge Standard of Water Pollutants.