好氧颗粒污泥处理低浓度生活污水同步脱氮除磷的分析-analysis of simultaneous nitrogen and phosphorus removal in aerobic granular sludge treatment of low-concentration domestic sewage.docx

AbstractMunicipal wastewater treatment plants often encounter the problem of insufficient carbon source, leading to poor removal performance of nitrogen and phosphorus. In view of this situation, this paper focuses on the three parts of work: the cultivation of adequate aerobic granular sludge; operation process optimization of aerobic granular sludge for simultaneous nitrogen and phosphorus removal; aerobic granular sludge - algae symbiotic system for phosphorus and nitrogen removal.The first part is the cultivation of aerobic granular sludge. In the condition of reactor with Ratio of height to diameter of 2 and low concentration influent with COD concentration of 200mg/L, aerobic granules could be cultivated successfully. Mature aerobic granules with yellow appearance, had perfect setting performance, whose SVI was stable between 20 ml/g ~ 40ml/g. The average particle size of aerobic granules cultivated with high strength and low strength influent were 1.02mm and 0.79mm.Maintaining short settlement time, reducing influent COD concentration and extending operation cycle time, decreasing the organic load rate and the growth rate of floc sludge,could be conducive to improving granulation rate and ensuring the successful cultivation.The second part is operation process optimization of aerobic granular sludge for simultaneous nitrogen and phosphorus removal. Aerobic granular sludge had very good performance in degrading organic matter and oxidizing ammonia. The stronger is the aeration and the longer is the cycle time, are the lower the effluent COD, ammonia and nitrite. Sludge age and anoxic time had little effect on COD, ammonia nitrogen removal performance. Nitrate was mainly removed by denitrification, suppressed by carbon source shortage; a certain anoxic time could be beneficial to the removal of nitrate. TP was removed mainly at the aerobic stage. The stronger is the aeration and the longer is the cycle, the lower the effluent TP. A certain degree of sludge remo