College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, China.
Water Environ Res. 2012 Aug;84(8):656-61. doi: 10.2175/106143012x13373550427390.
It is well known that model-building of chlorine decay in real water distribution systems is difficult because chlorine decay is influenced by many factors (e.g., bulk water demand, pipe-wall demand, piping material, flow velocity, and residence time). In this paper, experiments were run to investigate the kinetic model of chlorine decay and the formation model of trihalomethanes (THMs) in pilot-scale water distribution systems. Experimental results show that the rate constants of chlorine decay, including wall decay and bulk decay, increasing with temperature. Moreover, the kinetic model of chlorine decay and the formation model of THMs describe experiment data of pilot-scale water distribution systems. The effect of different piping material on chlorine decay and THMs formation were also investigated. The rate constants of chlorine decay are ranked in order: stainless steel pipe, ductile iron pipe, and last, polyethelene pipe because wall decay is the largest in stainless steel pipe than that in other piping material. Correspondingly, the rate of THMs formation follows the order of stainless steel pipe, ductile iron pipe, and last, polyethelene pipe because of less chlorine in bulk water reacting with the trihalomethane formation potential (THMFP).
众所周知，由于氯的衰减受到许多因素的影响（如总需水量、管壁需求、管道材料、流速和停留时间），因此很难对实际供水管网中的氯衰减进行建模。本文通过实验研究了在中试规模供水管网中氯衰减的动力学模型和三卤甲烷（THMs）的形成模型。实验结果表明，包括壁衰减和体衰减在内的氯衰减速率常数随温度升高而增加。此外，氯衰减的动力学模型和 THMs 的形成模型描述了中试规模供水管网的实验数据。还研究了不同管道材料对氯衰减和 THMs 形成的影响。氯衰减速率常数的顺序为：不锈钢管、球墨铸铁管、最后是聚乙烯管，因为不锈钢管中的壁衰减比其他管道材料大。相应地，由于与三卤甲烷生成潜力（THMFP）反应的总需水中的氯较少，THMs 形成的速率遵循不锈钢管、球墨铸铁管、最后是聚乙烯管的顺序。
