镇江水厂前置调蓄池污染物扩散数值模拟

NUMERICAL SIMULATION OF DIFFUSION OF CONTAMINANT IN PRESTORAGE BASIN IN ZHENJIANG WATERWORKS

以镇江水厂水源安全保障工程前置调蓄池为对象,采用水环境模拟软件EFDC建立调蓄池三维数值模型,开展水动力学和污染物迁移数值模拟,预测不同流量工况下污染物进入调蓄池后到达取水口时间,分析了污染物的输移规律。研究结果表明:若发生污染事件,污染物基本沿着调蓄池水流方向扩散,污染云团面积逐渐增大,浓度逐渐减小;随着扩散距离逐渐增大,污染物扩散速度逐渐减小;3种不同流量工况下,污染物扩散至调蓄池出水口时间都在10 h以上,满足设计要求。建设前置调蓄池能够在突发事故时延缓污染水体进厂,给应急处置提供时间,对保障供水安全具有重大意义。

Taking the prestorage basin( a safety assuring facility) of Zhenjiang waterworks improvement project as the example,simulation and calculation on hydrodynamic and pollutants transportation of the prestorage basin was carried out,through a three-dimensional numerical model built by EFDC software. We predicted the time points of pollutants entering the outlet of storage basin under different flow conditions,analyzed the transport law of pollutant diffusion. The results showed that,if contamination accident happened,the pollutants basically spread along the direction of the water flow;the area of the pollution cloud increased and the concentration decreased gradually;as the diffusion distance of pollutants increased,the diffusion rate decreased gradually;under three different flow conditions,the pollutant diffusion time of water outlet was all above 10 h,meeting the design requirements. Prestorage basin was proved to be able to delay the pollutant entering the waterworks and provide the emergency treatment time,so it was significant to construct the prestorage basin for assuring the water supply safety.