Simultaneous Nitrogen and Phosphorous Removal Under Low DO in a Hybrid Biological Reactor
复合生物反应器低溶解氧同步脱氮除磷

Study was conducted by use of the mixed organism of activated sludge and suspended biofilm coexisting in a hybrid biological reactor (HBR) system for simultaneous nitrogen and phosphorous removal. The experimental results showed that, DO and COD/TN were the main factors affected the effluent , the maximum phosphorous releasing rate (the rate that PO43--P concentration at releasing end to the initial PO43--P concentration) was 249%, TN removal efficiency was 80.0%, PO43--P removal efficiency was 92.2% by controlling the aeration rate (Qair) at 0.07m3/h, TN and PO43--P removal efficiency will be decreased, whenever aeration rate increasing or decreasing. With the increasing of COD/TN, the TN and PO43--P removal efficiency was increased, TN removal efficiency was increased from 70.3% to 84.9% , PO43--P removal efficiency was increased from 82.2% to 96.0%, when COD/TN was increased from 3.2 to 10.5. The SVI of the activated sludg was less than 90ml/g during the experiments. It was found during the research process that high phosphorus and nitrogen removal efficiency can be simultaneous achieved without anaerobic and anoxic phase , which was conventionally considered as a key phase for phosphorus and nitrogen removal.