To solve the problem of the unsatisfactory effluent ammonia concentration in the A2N-IC-SBR (anaerobic/anoxic/nitration-induced crystallization-sequencing batch reactor) process
improvement measures were taken. Nutrient removal performance was investigated in the improved system. Ammonia removal rates increased significantly without any negative effect on phosphorus removal. After the improvement measures
effluent ammonia
total nitrogen and total phosphorus all reached the Chinese National Sewage Discharge Standard Class I (grade A) level. Compared with A2N-IC-continuous flow process
obvious advantage of enhancing phosphorus recovery was noticed. Calcium could be added continuously and evenly during the chemical phosphorus recovery reaction stage
benefiting heterogeneous precipitation. And plate-shaped crystallization product was formed on the seeds.