基于污染带特征指标控制的秃尾河流域总量研究

秃尾河作为黄河上游主要一级支流,是陕西省内重要的水源及纳污河段,故开展秃尾河总量控制研究对保护流域内水环境质量及维持西北、华北区域社会经济稳定具有重要意义.提出了以污染混合带长度与污染混合均匀断面水质质量浓度等污染带特征指标作为控制因子来进行污染控制总量确定的方法,并利用已率定验证合理的秃尾河二维水环境数学模型,分别对现状排污方案、区域环评规划排污方案及后续水环境研究专题报告专家推荐削减方案等3套不同方案进行水质模拟,通过对不同方案形成的污染带特征进行分析,得到以下结论:根据秃尾河流域水质、水文同步监测数据率定秃尾河水环境数学模型,确定了二维模型参数,其中糙率R为0.029~0.033;COD的降解系数为0.10~0.14 d-1,氨氮降解系数为0.09~0.12 d-1,污染物横向扩散系数为0.88 m2/s.根据模型计算结果,确定专家推荐削减方案可满足控制条件,即基于污染带特征指标控制下的秃尾河流域控制排放总量分别为氨氮0.185 t/d,COD 1.25 t/d.

Total Amount Control in Tuwei River Basin Under the Control of Characteristic Parameters of Pollution Zone

As the first grade tributary of the Yellow River basin, Tuwei River is significant because it is not only an important water source but also a pollutant receiving river in the basin. It is urgent to carry out researches on total amount controlling in Tuwei River to maintain the water quality. In this paper,the length of pollution mixing zone and pollutant concentration of pollution mixing section were used as the control parameters to quantify the total pollutant amount. A two-dimensional mathematical model of water environment which had been suitably calibrated and validated was applied to simulate 3 different kinds of water environmental situations at different conditions: the current situation without any pollutant reduction, the situation with pollutant reduction proposed by government and the situation with pollutant reduction proposed by experts. The results showed that:1 ) the bed roughness of Tuwei River basin was from 0. 029 to 0. 033 , the degradation coefficient of COD was 0. 10 - 0. 14 d-1 , the degradation coefficient of NH3-N was 0. 09-0. 12 d-1 , and the transverse diffusion coefficient of pollutants was 0. 88 m2/s. 2) it was also found that only the pollution reduction condition proposed by experts could reach the standard with the total amount of NH3-N 0. 185 t/d and COD 1. 25 t/d.