Start-Up Of HITNP Denitrifying Phosphorus Removal Process As Well As Its Affecting Factors

The massive nitrogen and phosphorus flows in the water body, has caused waterbody eutrophication. The conventional sewage biological treatment process of nitrogen and phosphorus removal, no matter in theory or in practice, is difficult to solve the competitive relationship between microorganism of nitrogen and phosphorus removal. This project is based on the new mechanism of denitrifying phosphorus removal and designs a set of denitrifying phosphorus removal system---- HITNP ( Harbin Institute of Technology Nitrogen and Phosphorus removal).This nutrient removal process was a combined activated sludge and fix-film process, worked with supernatant recycle regime. Hybrid Activated sludge-biofilm reactor was applied in the experiment unit to solve the problem of overgrowing of slow growing nitrifiers by fast heterotrophs. The"double use"of PHB in the denitrifying phosphorus removal bacteria can achieve the purpose of simultaneous biological phosphorusan nitrogen removal. High anaerobic sludge concentration originated from supernatant recycle and total anaerobic/aerobic sludge recycle of HITNP other than part sludge recycle of traditional configuration contributed to high phosphorus removal efficiency.DPB was induced cultivated and reproducted by adopting three operation modes and acrylics off-lying the vinyon stand bar was coated with nitrobacterium nitrifying bacteria. After completing the domesticated raise of the sludge and the reactor successful start-up, we studied a lot of control factors ,then ,we found COD/TN,the concentration of nitrate,MLSS,HRT,ORP,PH and SRT etc can impact the efficiency of the process. When COD/TN ratio ranged among 5~7, SRT was 10d and ORP was under -200mv, HITNP process could achieve optimal condition. Study was made on the use of artificial waste water, the research results showed that the process has removal rate of 90%,93%,64%and 81% respectively for COD,NH4+-N,TN and TP, and the effluent concentration of COD,NH4+-N,TN and TP were observed to be 28mg/L,2.7 mg/L,19.1 mg/L and 2 mg/L in average. The outfall quality of COD,NH4+-N,TN and TP can reach the second class discharge standard in GB18918-2002.