For purification of eutrophic lake water

immobilized nitrogen cycle bacteria (nitrobacteria- denitrifying) made from radiation copolymerization at low temperatures by means of glass forming monomers

i.e. 2-hydroxyethyl acrylate (HEA) and polyethylene glycol dimethacrylate (14G) were used. The Sequencing Batch Reactors (SBR) system and cell growths of nitrogen cycle bacteria techniques were carried out in order to treat eutrophic lake water. The results showed that the removal efficiencies for total N (TN)

NH + 4-N and COD with immobilized nitrogen cycle bacteria were 75%

91.5% and 75% respectively. The results demonstrated that the optimum temperature of immobilized nitrogen cycle bacteria system was 28℃. Immobilized nitrogen cycle bacteria system was more resistance to low temperature (10℃). The disolved oxygen (DO) concentrations have effect on removal efficiencies for TN.