岷江大桥控制单元水体氨氮和总磷源解析

Source Apportionment of Ammonia Nitrogen and Total Phosphorus of Minjiang Bridge Control Unit

采用单因素法对岷江流域国控断面的岷江大桥水体进行评价,从污染源分担率、污染物时空变化等方面解析污染物的主要来源与变化。结果表明,水体不达标的主要因子为氨氮和总磷;污染物的主要来自城镇生活污水和规模化畜禽养殖废水的不达标排放,按各个污染源占比统计,2个主要污染源对于氨氮和总磷的污染分担率分别是42.54%、35.31%;受上游来水、其他补给水源的影响,氨氮浓度集中在1~5月超标严重,在2013年4月份出现峰值,总磷在2011~2014年普遍超标严重,在2014年5月出现峰值,由于"十二五"期间治污力度的加强,2015年氨氮污染趋势得到控制,总磷浓度明显有所降低,MIKE 21二维水动力水质模型模拟显示只要汇入支流断面均达到要求、污染负荷得到有效控制,控制单元能满足达标要求;最后从源头减排、区域综合整治、全程监管3个方面构建了使控制单元水体达标的策略。

The Minjiang river bridge was a state-controlled unit of Minjiang basin, its water quality was assessed by the single-factor method, and its main pollution source and change were analyzed by the proportion of the pollution sources, and temporal and spatial changes of the pollutants. It was shown that the main over-standard factors were ammonia nitrogen and total phosphorus, mainly due to excessive discharge of urban sewage and livestock wastewater. By the proportion of the pollution sources, the two main sources ammonia nitrogen and total phosphorus contribute for 42. 54% and 35. 31% , respectively. Influenced by upstream and other inflow resources, the concentration of ammonia nitrogen was way beyond the standard from January to May, and peak at April,2013. The concentration of total phosphorus was generally beyond the standard in 2011 ？2014, and peak at May, 2014. Because of the reinforced control during the 12th five-year, the pollution tendency of ammonia nitrogen was controlled and the concentration of total phosphorus was reduced in 2015. MIKE 21 two-dimensional hydrodynamic model showed that the Minjiang river bridge section could reach the standard if the upstream branches met the requirements and the pollution load gets effective controlled. Finally, the strategy for the control unit was set up from the source reduction, regional comprehensive regulation and the whole process management.