广东大中型供水水库的氮污染与富营养化分析

20 0 0年丰水期和枯水期对广东大中型水库的氮污染和富营养化现状进行了调查。结果表明 ,在调查的 2 0个大中型供水水库中 ,水质现状总体较好 ,70 %的水库处于中营养状态以下 ,30 %的水库开始出现富营养化现象。水库的总氮浓度普遍偏高 ,氮污染成为水库富营养化的重要原因。水库的总氮和DIN浓度存在地区性差异和季节性差异。枯水期水库的总氮及DIN浓度与叶绿素a的相关性极显著 ,而丰水期则无明显相关性。NO3 N是水体无机氮的主要组成部分 ,平均占DIN的 72 6 % ,而水库的NH3 N含量明显低于NO3 N ,平均占DIN的2 5 5 %。NO2 N的含量一般很低。水库的总氮、DIN和有机氮含量是判断水库营养状态的重要指标 ,而NO3 N和NH3 N在DIN中所占比例则是推测污染物来源的重要依据

Analysis on nitrogen pollution and eutrophication of the large and medium reservoirs for water supply in Guangdong Province

Investigation and monitoring on nitrogen pollution and eutrophication status of the large and medium reservoirs for water supply in Guangdong Province were carried out in flood season and dry season of 2000.Water temperature,DO,pH,chlorophyll a,COD Mn,turbidity,TN,TP,NO 3-N,NH 3-N,NO 2-N and PO 4-P were determined synchronized with phytoplankton.The study revealed that the water quality of the reservoirs was still generally good.Among the 20 reservoirs,70% of them were situated in oligotrophic to medium trophic status,and 30% of them showed eutrophic features.The concentration of TN was generally higher,and nitrogen pollution was one of the important factors involved in eutrophication.TN and DIN fluctuated with the area as a result of the difference in character and environmental status.Seasonal dissimilarity existed too.Statistical analysis revealed that the concentrations of TN and DIN were positively related to chlorophyll a in dry season.However the relationship was not obvious in flooding season.As the primary composition of DIN in water body,NO 3-N accounted for 72 6% of DIN on the average.The concentration of NH 3-N was obviously lower than that of NO 3-N which constituted 25 5% of DIN on the average.The concentration of NO 2-N was relatively low.The concentration of TN,DIN and organic nitrogen were important targets used to distinguish the trophic status of the reservoirs.And the percentage of NO 3-N and NH 3-N among DIN was important basis used to estimate the source of the pollution.