Study On The Technology Of Denitrification Phosphorus Removal Using Nitrite As Electron Acceptor

The process of denitrification phosphorus removal using nitrite as electron acceptor hadmany advantages not only with high effective phosphorus removal, the good settling ability ofactive sludge and easy to dewater, but also with less energy consumption, less carbon sourceconsumption and less sludge yield.Aimed at the SBR (Sequencing Batch Reactor) used to treat the synthetic wastewater, theprimary mechanism of denitrification phosphorus removal was investigated in the present thesis.Based on the investigation of domestication and factors for nitrosomanas and denitrifiactionphosphorus removal bacterium, the feasibility of the process of denitrification phosphorusremoval was involved too. The main results of this thesis were as followings:1. Theoretically, the substitution of nitrate and oxygen by nitrite had advantages. Theenzymes in DPB could decomposed and finished denitrification and phosphors uptake.2. The nitrite could be continuously accumulated in the SBR by controlling theenvironmental factors. It was favorable to accumulate the nitrite under the temperature of 28±3℃, DO of 0.4mg/L, alkalinity of 1290mg/L, pH of 8.0±0.2.3. The key of the SBR startup was the nature of the electron acceptors. The start-up withnitrite was one of the most fast and effective methods to acclimate DPB sludge. The highestconcentration of nitrite to inhibit DPB was 150 mg /L under conditions examined.4. The process of denitrification phosphorus removal using nitrite as electron acceptor wasfeasible. The efficiency of phosphorus removal was optimal with the removal of above 70%under COD concentration of 400mg/L, COD: PO43--P of 50, COD: NO2--N of 13 and SRT of22~30d.