合流制溢流污染控制实践:以岳阳蛇皮套泵站为例

岳阳市蛇皮套泵站及调蓄池改造工程是典型的合流制溢流污染控制工程,设计通过科学的管网水力模型与系统的水文建模分析,基于海绵城市建设理念,在排口末端采用调蓄池与生态滤池组合工艺处理溢流水,达到精准治污的效果,并将处理设施结合景观设施进行设计,将黑臭水体改造为海绵公园。介绍了项目的基本情况以及泵站、调蓄池、生态滤池的设计规模和运行工况,并对设计方案进行长历时水文模型验证。模拟结果表明,在经济允许的情况下,采用该工艺措施可使受纳水体的溢流污染得到一定的控制,单位硬化面积的溢流COD污染负荷低于250 kg/(hm^2·a),生态滤池出水COD平均值为10.2 mg/L,生态滤池溢流频次为12.2次/年,调蓄池截流的COD污染负荷为2 343 t/a,生态滤池去除的COD污染负荷为105 t/a,分别占COD污染总量的48.2%和2.2%,而溢流污染量仅占2.3%,达到了一定的面源污染控制要求,生态环保效益明显。

Combined Sewer Overflow Control Engineering Practice: A Case Study of Shepitao Pumping Station in Yueyang City

Shepitao pumping station and storage tank reconstruction project in Yueyang City is a typical combined sewer overflow(CSO)control project.Based on the scientific drainage modeling and systemic hydrological modeling analysis and the concept of sponge city,the storage tank and retention biofilter at the end of drainage outlet were built in order to achieve accurate pollution control effect,and the treatment facilities were designed in combination with landscape facilities to transform the black odorous water body into a sponge park.The basic conditions,scale and operational conditions of the storage tank,pumping station and retention biofilter were introduced,and model verification through long-term rainfall hydrology simulation was carried out.The simulation results showed that,under the condition of economic permission,the CSO pollution of the receiving water body was controlled to a certain extent after adopting the process.The overflow COD pollution load per unit area was less than 250 kg/(hm^2·a),the COD average concentration in the effluent of the retention biofilter was 10.2 mg/L,and the overflow frequency of the retention biofilter was 12.2 times per year.The COD pollution load intercepted by the storage tank was 2343 t/a,and the COD pollution load removed by the retention biofilter was 105 t/a,accounting for 48.2%and 2.2%of the total COD pollution load,respectively.The overflow pollution only accounted for 2.3%,indicating that certain requirements for non-point source pollution control were achieved and the ecological and environmental protection benefits were obvious.