Abstract:

By using pollution source survey data, sewage treatment plant data, sediment monitoring results and SWMM, this study estimated the non-point source and overflow load of the basin. By analyzing the spatial and temporal distribution of major pollutants, the following results were obtained. 1) The chemical oxygen demand (COD), ammonia nitrogen (NH₃-N) and total phosphorous (TP) loads in Shenzhen River basin in 2015 were 36760 t/a, 5715.65 t/a and 494.36 t/a, respectively. The COD, NH₃-N and TP loads of the point source were 26300 t/a, 5496.9 t/a, and 463.55 t/a. The point source accounts for 72% of COD, 96% of NH₃-N, and 94% of TP of the whole year. The COD, NH₃-N and TP loads of the non-point source were 8608 t/a, 99.8 t/a and 18 t/a. The COD, NH₃-N and TP loads of the overflow in rainy season (April to September) were 1894.05 t, 118.95 t and 12.81 t. 2) The COD, NH₃-N and TP loads in Shenzhen Bay basin in 2015 were 116.5 t/d, 15.75 t/d and 1.412 t/d; the sewage outlets and the leakage sewage to tributary were the largest proportion of all source during the dry season. The COD, NH₃-N and TP loads of the point source were 71.94 t/d, 15.06 t/d, and 1.27 t/d during the dry season. During the rainy season, the non-point source COD accounted for the largest proportion (34.21%), followed by and the leakage sewage to tributary and the sewage outlets, which were 28.73% and 22.3%. 3) Due to a large amount of pollutant load were transported into the waterbody, the pollutant load from non-point source and overflow considerably effected the water quality during the rainy season that could not be ignored, especially in the rainy days, and it took a long time to return to normal water quality.

Key words: Shenzhen Bay basin, water source apportionment of pollution, SWMM, non-point source pollution

摘要：

利用污染源调查资料、污水处理厂运行数据、底质监测结果、SWMM的非点源污染模型和截排系统溢流模型, 估算深圳河湾流域的非点源和溢流污染负荷, 解析流域主要污染物的时空分布和来源, 得到如下结论。1) 2015年深圳河湾流域全年入河负荷量为COD 3.676 万 t/a, 氨氮 5715.65 t/a, TP 494.36 t/a, 其中点源为COD 2.63 万 t/a, 氨氮 5496.9 t/a, TP 463.55 t/a, 占全年的比例分别为72%, 96%和94%。非点源负荷为COD 8608 t/a, 氨氮 99.8 t/a, TP 18 t/a。雨季(4—9 月)溢流总负荷为COD 1894.05 t, 氨氮 118.95 t, TP 12.81 t。2) 深圳河湾流域单日入河负荷为COD 116.5 t/d, 氨氮 15.75 t/d, TP 1.412 t/d; 旱季污染源中漏排污水, 各指标负荷属排污口和支流漏排占比最大; 旱季点源总COD为71.94 t/d, 氨氮为15.06 t/d, TP为1.27 t/d。雨季中, 非点源的COD占比最大(34.21%), 其次是支流漏排(28.73%)和排污口(22.3%); 3) 雨季非点源和溢流的负荷对水质的影响不能忽略, 尤其是暴雨天, 虽然时间短, 但大量负荷对水质冲击的影响极其严重, 恢复到正常水质需较长的时间。

关键词: 深圳河湾流域, 污染源解析, SWMM, 非点源