潼湖流域污染负荷与水环境容量

Pollution Load and Environment Capacity in Tonghu Lake Basin

以广东省潼湖流域为研究区,综合环境监测和统计数据,运用排污系数法,对流域内6种污染源的污染排放情况进行分析;在水质监测的基础上,核算了流域水环境容量。结果表明,2014年潼湖流域化学需氧量入湖污染负荷为5 098.34 t/a,铵态氮入湖污染负荷为519.87 t/a,总氮入湖污染负荷为1 011.43 t/a,总磷入湖污染负荷为66.25 t/a。城镇生活污染物为潼湖流域的主要污染源,其对化学需氧量、铵态氮、总氮和总磷的贡献分别占污染负荷总量的42.0%、41.2%、48.3%和40.7%;其次是农业种植污染物,4种污染物分别占负荷总量的26.4%、38.7%、37.0%和19.7%;再次是工业污染物,分别占负荷总量的25.9%、13.1%、15.0%和18.7%;畜禽养殖、水产养殖和农村生活污染物对化学需氧量、铵态氮和总氮的贡献率很小,对总磷贡献率较大,分别占总磷污染负荷总量的8.1%、8.5%和4.4%。马过渡河、社溪河和甲子河流域的污染最严重;对污染负荷贡献最大的乡镇是陈江街道,其次是惠环街道。

The study of pollution load and environment capacity is one of the key issues in water environment,water resources management and allocation in watershed. In this paper, a comprehensive analysis of water pollution load and environment capacity was conducted by the case study in Tonghu Lake basin, Guangdong province. Various sources of water pollution were quantitatively analyzed by plentiful of monitoring and statistic data as well as discharge coefficient. The coefficients, including export coefficient model, simplified one-dimension model, vollenwelder model and dillion model, were used to estimate environmental water capacity of Tonghu Lake and the sub-rivers. The results indicated that, 5 098.34 tons of chemical oxygen demand, 519.87 tons of ammonium nitrogen, 1 011.43 tons of total nitrogen, and 66.25 tons of total phosphorus were discharged into Tonghu Lake in 2014. Water pollution was mainly ascribed to urban domestic sewage,about 40% of the chemical oxygen demand, ammonium nitrogen, total nitrogen and total phosphorus. The industrial pollution also contributed significantly to the total pollution load caused by surface runoff pollution from cropland and urban construction land. Besides these, pollution from livestock, aquiculture and rural residents made relative small contributions to chemical oxygen demand, ammonium nitrogen, total nitrogen except total phosphorus. The results also show that, the Maguodu River and Shexi River were more serious than that in other rivers in Tonghu Lake basin. Chenjiang Street is the biggest pollution contributor, followed by Huihuan Street among the seven towns in the study area. The results show that, pollution in the rivers and lakes in Tonghu Lake basin were far in excess of its diminished capacity according to the current water quality management target. The discharges of total nitrogen and total phosphorus in Shexi River, Jiazi River and Maguodu River even exceeded 10 times of the environmental constrains. Therefore, more measures need to be taken to maintain the total quantity control of pollutants.