Optimization and Stability of Denitrifying Phosphorus Removal in a Two-Sludge System for Treating Wastewater with Low Carbon Source
A2N系统中低碳污水的反硝化除磷优化及运行稳定性

Poly-beta-hydroxybutyrate (PHB) could be efficiently accumulated under optimized conditions in a sequencing batch moving bed biological reactor (SBMBBR), and a high performance of denitrifying phosphorus removal in the reactor could be achieved by coupling with a two-sludge system. Denitrifying phosphorus removal achieved the highest efficiency under influent COD of 200 mg/L, neutral pH and stirring speed of 80 r/min. The removal rates of phosphorus, NO3(-)-N and NO2(-)-N reached 83.7%, 81.4% and above 100%, respectively. High biomass in the SBMBBR is one of keys to improve the performance in removal of nitrogen and phosphorus. When the SBMBBR was conducted under a two-sludge system, stable and high performance was obtained. Removal rates of phosphorus and TN reached 89.2% and 84.5% under the influent COD of 140-170 mg/L and TN of 34-42 mg/L, respectively. In the process, phosphorus content in excess sludge approached to that in the feeding, and other path of phosphorus removal was not found.