鄱阳湖入湖河流氮磷水质控制限值研究

鄱阳湖近年氮磷营养物浓度逐步升高，入湖河流是鄱阳湖氮磷输入的重要途径.采用BATHTUB模型建立了鄱阳湖入湖河流与湖区ρ（TP）、ρ（TN）的响应关系，模拟了入湖河流执行GB 3838—2002《地表水环境质量标准》中不同氮磷标准限值对湖区水质的影响，发现当入湖河流ρ（TP）执行河流Ⅲ类标准限值或超过Ⅲ类标准限值时，对应湖区ρ（TP）超标；入湖河流执行Ⅲ类及以上湖泊水质标准限值时，湖区水质可以达到Ⅲ类保护目标，但对入湖河流存在一定的过保护现象.因此，以满足现行湖泊水质达标为情景，以湖泊ρ（TP）、ρ（TN）各类别标准限值为目标，试算了入湖河流氮磷控制限值，提出了鄱阳湖入湖河流的氮磷控制限值建议方案，其中鄱阳湖湖体水质目标为Ⅲ类时，入湖河流ρ（TP）、ρ（TN）控制限值分别为0.075和1.20 mg/L，此时入湖河流氮磷控制限值方案既能保证湖泊水质达标，又不会造成对河流的水质控制过于严格.研究显示，基于湖泊水环境质量达标情况试算的入湖河流氮磷所需控制限值，建议可作为解决入湖氮磷污染控制问题的参考. 

Water Quality Limits of Nitrogen and Phosphorus in the Inflow Rivers of Poyang Lake

In recent years, the concentration of nitrogen and phosphorus in Poyang Lake has gradually increased, and river nutrient input is an important way for nitrogen and phosphorus in Poyang Lake. The BATHTUB model was used to simulate the relationship between TP and TN in the rivers and lake, and the effects of different nutrient standard limits on the water quality of the rivers entering lake. The study found that when ρ(TP) in rivers into Poyang Lake implemented or exceeded Class Ⅲ (Environmental Quality Standards for Surface Water(GB 3838-2002) of standard river limits), ρ(TP) in Poyang lake would exceed the standard. When the nutrient in rivers entering Poyang Lake implemented the standard values of lakes of Class Ⅲ and above, it could meet the standards, but there was a certain over-protection phenomenon. Therefore, in order to meet the current lake water quality standards, taking the different standard limits of TP and TN in lake as targets, calculate nutrient control limits for rivers entering lakes, and recommendations for the water quality control limits of the rivers entering Poyang Lake are proposed. The TP and TN control limits of the rivers entering the lake should be 0.075 and 1.20 mg/L respectively if the water quality target of Poyang Lake is Class Ⅲ, which can ensure that the water quality of the lake meets the standards and avoid that the control limits of the rivers are too strict. Studies have shown that the calculated control limits of nitrogen and phosphorus in lakes can be suggested as a reference for solving the problems of nitrogen and phosphorus pollution control in lakes, based on lake water environmental quality standards.