深圳河湾流域溢流污染规律及其对海湾水质的影响

以深圳河湾流域为研究对象, 基于流域降雨径流污染?沿河截排系统溢流?海湾水动力水质联合模型, 分析研究区溢流污染输出的时空变化规律及其对海湾水质的影响。结果表明, 全年流域主要污染源为污水处理厂尾水污染和溢流污染; 溢流污染占入河湾总污染负荷的30%左右, 雨季升至50%左右, 成为深圳河湾流域雨季最主要的污染源; 溢流污染负荷季节差异性显著, 雨季占全年总负荷的85%以上; 溢流污染负荷随降雨量增加而增加, 当降雨强度相差不大的时候, 雨前干旱时间越长, 溢流污染负荷越大; 深圳湾内湾水质比外湾差且波动更明显, 雨季内湾及湾中水质比旱季差且波动更大; 在场次降雨情况下, 内湾水质波动受溢流污染冲击影响最严重, 湾中及外湾水质波动主要受潮汐作用影响; 在降雨重现期为0.25~0.5 年(2小时降雨约45~60 mm)时, 深圳湾水质超标最明显, 水质受溢流污染冲击影响的持续时间为12~20天。

Impact of Overflow Pollution on Water Quality in Shenzhen Bay

This study takes the Shenzhen Bay Basin as the research object, based on the combined model of rainfall runoff pollution, overflow from sewer interception system and hydrodynamic water quality in the bay, the temporal and spatial variation of overflow pollution and its effect on water quality in the bay were analyzed. The results show that in the whole year, the main pollution sources of the basin are the pollution of the wastewater treatment plant and the overflow pollution. The overflow pollution accounts for about 30% of the total pollution load, rises to about 50% in the rainy season, and becames the main pollution source in the rainy season in Shenzhen Bay Basin. The overflow pollution load in rainy season accounts for more than 85% of the total overflow pollution load in the whole year. The pollution load of overflow increases with the rainfall. When the rainfall intensity is similar, the longer the dry time before rain, the greater the overflow pollution load. In terms of water quality in the bay, the water quality in the Inner Bay is worse than that in the Outer Bay and the fluctuation is more obvious, In rainy season, the water quality in Inner Bay and Middle Bay is worse and fluctuates more than that in dry season. In the event of rain, the water quality fluctuation in the inner bay was most seriously affected by the impact of overflow pollution, while the middle and outer bays was mainly affected by the tidal action. When the return period of rainfall is 0.25 to 0.5 years, the water quality in Shenzhen Bay exceeds the standard most obviously, and the duration of water quality affected by overflow pollution is 12 to 20 days.