不同污水排海方式对南通通州湾海域水质的影响

采用数值模拟的方法，在污水排放规模为10万m3/d，COD浓度为50 mg/L的情况下，计算并分析了24 h连续排放、高潮时至落急、高潮时至低潮时3种排污时段下分别位于-4 m、-6 m、-8 m和-10 m 4个水深位置的不同污水排海方式情况下，污染物输移扩散对南通通州湾海域的影响。结果表明，由于水动力条件的不同，不同位置排放口的绝对影响范围也产生变化，且随着水深的增加，水交换能力越强，污染物影响范围越小；在排放总量一定的情况下，不同时段排放时，污染物影响范围也不同，24 h连续排放对水环境影响最小，高潮时到落急、高潮时至低潮时时段排放时一定程度上控制了高浓度污染物扩散对近海海域的影响。

Effect of different sewage discharge methods on sea water quality of Tongzhou bay in Nantong

The effect of sewage discharge on sea water quality in Tongzhou bay is calculated and analyzed by the numerical simulation method. Sewage water is assumed to discharge at the water depth of -4 m, -6 m, -8 m and -10 m during whole day、from high water stand to fastest ebb、from high water stand to low water stand while the sewage discharge rate is 100000 m3/d and the concentration of COD is 50 mg/L.The results show that the affected areas are different because of different hydrodynamic conditions.With the increase of water depth, the water exchange capacity is stronger, and the affected areas become smaller; Under the certain amount of sewage, the affected areas are also changed while sewage is discharged in different time period. The effect is minimal when sewage water is discharged during whole day, but discharging sewage from high water stand to fastest ebb and from high water stand to low water stand prevents sewage from polluting coastal waters to a certain extent.