[Variations and transformations of nitrogen pollutants in source and tap water of D-lake]

Ammonia, nitrite and nitrate pollutions and variations in source water and tap water of D-Lake are investigated. The removal effects of nitrogen in routine proceeding of water production and the transformations of the different forms of nitrogen in natural condition with simulated test are studied at the same time. The results show that the nitrogen pollutions in source and tap water of D-waterworks are higher than T-waterworks', although both waterworks have same resource. Compared with D-waterworks, the nitrogen pollutions of source and tap water in Z-waterworks are lower than D-waterworks' and they have different variation and distribution. The forms of nitrogen could be partly transformed during the routine production, but the total percentage of nitrogen removal efficiency is not significant (just about 20%). The simulate test shows that NH4+(-)N could change into NO2-(-)N, while No2-(-)N into NO3-(-)N, which is partly transformed into nitrogen gas by microorganism and majority of which are remained in tap water by form of NO3-(-)N.