合流制排水系统溢流污染控制策略的系统动力学分析

System dynamics analysis on the strategy for controlling the pollution of the combined sewer overflow

为了探索城市合流制排水系统溢流污染的控制策略,基于合流制排水系统结构特征,应用系统动力学方法构建了溢流污染控制系统动力学模型。该模型分为污染源产生子系统、收集运输子系统、污水溢流子系统、污水处理子系统及受纳水体子系统5部分,每个子系统相互作用构成完整的系统动力学模型。将该模型应用于镇江市老城区合流制排水系统溢流污染控制规划,从排水系统的源-流-汇三方面(包括源头减污、过程控污、末端治污和综合集成),模拟分析各种溢流污染控制策略的效能。

The present paper intends to propose a system dynamic model as a set of strategies for controlling the pollution of the com- bined sewer system overflow. Thus, it can be said oriented in explor- ing the possibilities to effectively control the overflow pollution in the combined sewer system network by taking the old areas of Zhenjiang city, Jiangsu, as a case study sample. The model of ours intends to be divided into five subsystems, that is, the pollution sources subsys- tem, the collection and transportation subsystem, the overflow subsys- tem, the sewage processing subsystem and the receiving water body subsystem, with each one of them made to interact with each other.In proceeding with our research, we have managed to simulate the ef- ficiency of the various kinds of strategies for controlling the said sewer overflow pollution from the pollution source, the stream and the col- lection, including in detail the pollution-reducing points, the poilu- tion-controlling in processing, and the pollution-treating in the final and integrated control and management. The final results of our model tell us that the strategies to reduce runoff coefficient can effectively reduce the sewage volume and COD load by 26 % and 7 % . Although the strategies to reduce pollution load of the earth＇ s surface can help to reduce COD load of overflow by 50% at the peak, merely reduce 15% of the total COD load. It means that the pipeline flush can re- duce over half of COD load and 45 % for the total COD load. Be- sides, the strategies to repair the pipeline for controlling the permeat- ing are beneficial to control overflow. The strategies to adjust the in- tercepting multiple from one to three can reduce only 3 % total over- flow pollution volume, 15% COD load of overflow at the peak. On the condition that the additional treating equipment is set up, the strategies can be expected to reduce the total COD load by 58.6% . Furthermore, the comprehensive strategies can also be promising to reduce 1/3 of the sewage volume, including over 40% of COD load. All these advantages of this model can surely find itself in offering a technical reference to the sewer network management and transforma- tion of Zhenjiang city, even a reference to other similar areas.