管材和水力条件对三卤甲烷形成的影响

Effects of pipe materials and hydraulic conditions on the formation of trihalomethanes

摘要:

针对管材和水力条件对氯消毒副产物(Disinfection By-Products,DBPs)产生过程的影响,研究了管材和水力条件对供水管网中典型的消毒副产物——三卤甲烷(Trihalomethanes,THMs)形成的影响情况,其中,管材对THMs生成的影响研究采用静态管段反应器来完成,水力条件对THMs生成的影响研究采用供水管网动态模拟装置来完成.静态试验的研究结果表明:在不同管材中,余氯衰减速率排序为球墨铸铁>PVC>不锈钢,而THMs的生成量排序为:PVC管>球墨铸铁管>不锈钢管.供水管网动态模拟试验结果表明:THMs的生成量与流速成正比,但相对于余氯的衰减速度,THMs的增加并不显著;当停留时间和流速同时对THMs的生成量产生影响时,THMs的变化取决于二者影响程度的大小;管径与THMs的生成量成正比;余氯、管材、流速和停留时间都是THMs形成的重要影响因素.

Abstract:

The effects of different pipe materials and hydraulic conditions on the formation of trihalomethanes(THMs) were investigated.Pipe section reactor was used for the research of pipe materials and dynamic simulation equipment of water distribution network was used for the research of hydraulic conditions.The results of pipe section reactor showed that the ranking of chlorine decay velocity in different pipe materials was ductile cast iron>PVC>stainless steel,while the ranking of THMs concentration was PVC>ductile cast iron>stainless steel.The results of dynamic simulation showed that a higher flow velocity of water caused higher THMs concentration,but it was not distinct compared with the decay of chlorine.When retention time and flow velocity affected the formation of THMs simultaneously,THMs concentration was dependent on the effect degree of the two factors.THMs concentration increased as pipe diameter was increased.Chlorine residual,pipe materials,flow velocity and retention time are all important effects for the THMs formation.