深圳河河口近10年典型污染物通量变化研究

根据2008—2017年连续水文观测数据和逐月水质监测数据, 采用LOADEST模型模拟估算主要污染物COD、氨氮、总氮和总磷的净通量, 得到深圳河河口近10年主要污染物通量的变化规律。结合降水和流域内污水处理厂运行情况, 分析影响污染物通量变化的自然因素和人为因素, 得到以下结论。1) 2008—2017年深圳河河口断面各污染物入湾净通量呈现明显的下降趋势, 总体水质情况有所好转, 但仍未达到《地表水环境质量标准》(GB3838—2002)中V类水目标要求。2) 2008—2017年各污染物净通量的季节性差异逐年变小。3) COD净通量与降雨量的相关性较强, 说明其污染来源多为非点源; 总氮、氨氮和总磷净通量与降水量的相关性相对较弱, 说明其污染来源多为点源。4) 污染物净通量与污水处理量明显负相关, 说明提高污水处理厂日处理能力和污水出水水质有助于河流水质的改善。

A Study of Pollutant Loads Variations in Shenzhen River Estuary in Recent Decade

This study applies a LOADEST model to hydrology and water quality data from 2008 to 2017 to examine the variation of pollutant loads in Shenzhen River estuary. These investigated pollutants include COD, NH3-N, TN and TP. The result from the LOADEST model, alone with situation of both precipitation and wastewater treatment plants, are used to analyze both natural and artificial impacts on the pollutants. The research concludes the following statements. 1) The net pollutant loads in Shenzhen River decreased significantly from 2008 to 2017, but still not enough to reach level V for river water quality standard (GB3838–2002). 2) The seasonal variations of net pollutant loads reduced from 2008 to 2017. 3) There is a strong correlation between precipitation and COD net load, which indicates that this pollutant is mainly originated from non-point sources. Precipitation and NH3-N, TN and TP net loads have weak correlations, which means that point sources are the main contributors of these pollutants. 4) There is a negative correlation between net pollutant loads and the amount of treated wastewater. This illustrates the enhanced capacity of waste water treatment plants, as well as the improved quality of discharged treated water will contribute to better water quality in Shenzhen River.