原型观测法在确定九龙滩水库污染物降解系数中的应用

摘要

In order to determine the degradation coefficients of pollutants, field observation of water quality in the Jiulongtan Reservoir was conducted during a low water period;the concentration distributions of main water quality factors, such as BOD5 , CODCr , and NH3-N, in specific sections were obtained through water quality sampling and laboratory experiments;and the longitudinal degradation coefficients of water quality factors in the Jiulongtan Reservoir were calculated using three cross-sectional characteristic concentration values. The results show that the degradation coefficients calculated by the perpendicular bisector surface concentration and section-averaged concentration are close, while the one calculated by the surface-averaged concentration presents a larger deviation, which is considered to be the result of combined influence and interaction of various complicated factors. When prototype observation is used to determine the degradation coefficients of pollutants in reservoirs of low-dam and run-of-river hydropower stations without branches or sewage inlets and there is a large number of monitoring sections, in order to improve the work efficiency, it is feasible to obtain the degradation coefficients only from the water samples at the perpendicular bisector surface of cross-sections based on verification in advance.%为了确定水体的降解能力，进行九龙滩电站库区枯水期水质原型观测，结合水质采样和室内试验计算得到库区特定断面的BOD5、CODCr、NH3-N等水质因子的浓度分布，并采用3种断面特征浓度值计算各水质因子的沿程降解系数。计算结果表明：按断面中垂线水面浓度值和断面浓度均值计算的平均降解系数比较接近，而按水面浓度均值计算的结果偏差较大；当采用原型观测法确定类似沿程无支流及排污口汇入的低坝径流式电站库区水体的降解系数且观测断面较多时，为提高工作效率，在先行验证的基础上，可以仅采集断面中垂线水面处的水样进行分析与计算。