Examination of Disinfectant Residual Decay and Organochloramine Formation in Drinking Water Distribution Systems

消毒剂如氯或氯胺在进入分配系统之前被添加到经处理的饮用水中，以防止病原体入侵、生物再生长，并最终确保消费者获得安全的水。由于水在分配系统中花费的时间可能延长以及与管道材料的相关相互作用，水质从离开处理厂到被消耗时经常发生变化。纽马克特镇在其整个分配系统中保持足够的消毒剂残留方面遇到了问题，这导致了昂贵的维护活动并加快了其管道更换。迄今为止，已花费100多万美元来缓解这一问题。必须更好地了解消毒剂衰减的机制，以便制定有效的补救计划。拟议的研究将研究纽马克特配水系统中消毒剂残留的衰减和形态，作为水化学、管壁相互作用、温度和水力条件的函数。为了促进这项研究，多伦多大学的饮用水研究小组设计了能够复制分配系统条件的管段反应器，使得这些问题可以在实验室的受控条件下进行评估。为了验证和确认结果，管段反应器将与管道回路系统并联运行，管道回路系统将连续进料来自分配系统的水。这种方法的应用将使我们能够确定具体的机制，负责加速一氯胺衰减分配系统，并最终为未来的操作和维护活动提供指导。

Disinfectants such as chlorine or chloramine are added to treated drinking water prior to entering a distribution system to protect against pathogen intrusion, biological regrowth and to ultimately ensure that consumer's receive safe water. Due to the potential extended periods of time that water spends in a distribution system and associated interactions with pipe materials, water quality often changes from when it leaves a treatment plant to when it is consumed. The Town of Newmarket has experienced issues maintaining a sufficient disinfectant residual throughout their distribution system, which has led to costly maintenance activities and accelerated their pipeline replacement. To-date, more than $1-million has been spent to mitigate this issue. Mechanisms responsible for disinfectant decay must be better understood such that effective remediation plans may be developed.The proposed research will examine the decay and speciation of disinfectant residual in the Newmarket distribution system as a function of water chemistry, pipewall interactions, temperature and hydraulic conditions. To facilitate this research, the Drinking Water Research Group at the University of Toronto has designed pipe section reactors that are capable of replicating distribution system conditions such that these issues may be evaluated under controlled conditions in a lab. To validate and confirm results pipe section reactors will be operated in parallel to pipeloop systems which will be continuously fed with water from the distribution system. Application of this methodology will allow us to identify specific mechanisms responsible for accelerated monochloramine decay in distribution systems and to ultimately provide guidance for future operation and maintenance activities.