Study on Process of Denitrifying Phosphorus Removal with Single Sludge System

摘要

This study investigated the effects of carbon-total nitrogen ratio (C/TN) and influent flow rate distribution ratio on nitrogen and phosphorus removal by a single-sludge system named anaerobic and aerobic flow end with anoxic activated sludge process. The results showed that C/TN was 10 and influent flow rate distribution ratio was 1:2:2:1, nitrogen removal and phosphorus uptaken are best, chemical oxygen demand can be reduced by 84 %, total nitrogen can be removed 81 %, phosphorus and ammonia nitrogen can be reduced by 86 and 84 %, respectively. Keep the C/P same, when C/TN rose from 10 to 20, total phosphorus removal decreased by 25 %, but total nitrogen removal rate increased. Denitrifying phosphorus accumulating organisms (DPAOs) uptaking phosphorus need nitrate or nitrite as electron acceptor, nitrogen decreased led to less electron acceptor. The less electron acceptor led to less phosphorus uptakes. As C/TN decreased from 10 to 5, phosphorus removal decreased too. Because keep the C/P same, C/TN decreased, P/TN decreased too. Remaining nitrate flow into anaerobic, anaerobic phosphorus release and phosphorus uptakes was inhibited. Changing the influent flow rate distribution ratio has little influence on nitrogen removal and phosphorus uptakes. It was indicated that anaerobic and aerobic flow end with anoxic activated sludge process can work well even under strong impact.