Annular reactors and UV collimated beam apparatus for research of integrated disinfection of drinking water

控制供水系统中的微生物再生长是饮用水工业中公用事业公司主要关注的问题之一。如果在管道表面形成细菌聚集区，或称生物膜，会导致致病微生物的增加、管道材料的生物腐蚀和管道系统中的水头损失。消毒通常是控制管道系统中生物污垢的关键步骤。*由于对消毒剂及其副产品的监管越来越严格(即美国环保局第二阶段D/DBP规则)，供应商正在努力保持剩余保护和控制生物膜的形成和符合饮用水标准。消毒剂组合可以形成一个综合的消毒策略，加强对进入分配系统的微生物病原体的去除。尽管该领域的研究有限，但兰德博士进行的初步研究表明，紫外线和氯基消毒剂在减少散装水和生物膜细菌方面存在协同效益。饮用水行业的公用事业公司可以从协同作用中受益，在不增加化学消毒剂剂量的情况下实现更高的细菌去除。然而，在协同作用成为被接受和使用的理论之前，还需要更多的研究。兰德感兴趣的是使用替代消毒策略来模拟分配系统，以进一步利用实验室规模的设备来研究协同效应。环形反应器(ARs)作为模拟分配系统的工具被广泛接受，因为它们具有促进生物膜形成的独特能力，同时独立控制水力停留时间和剪应力。准直紫外光是实现准确剂量的有效方法，目前在大西洋加拿大还没有这样的设备。

The control of microbial regrowth in distribution systems is one of the primary concerns for utilities in the drinking water industry.  The formation of clusters of bacteria, or "biofilm", on pipe surfaces can lead to an increase in pathogenic microorganisms, biocorrosion of pipe material and headloss in the pipe system.  Disinfection is often the key step in controlling biofouling in pipe systems.  Due to increasingly stringent regulations on disinfectants and their byproducts (i.e., Stage II D/DBP Rule, USEPA), suppliers are struggling to maintain a balance between residual protection, control of biofilm formation and compliance with drinking water standards.It is plausible that disinfectants in combination can form an integrated disinfection strategy that enhances removal of microbial pathogens entering the distribution system.  Although research in the area is limited, preliminary studies conducted by Dr. Rand have shown that synergistic benefits exist between UV light and chlorine-based disinfectants in the reduction of bulk water and biofilm bacteria.  Utilities in the drinking water industry could benefit from synergy by achieving higher removal of bacteria without increasing chemical disinfectant dose.  However, much more research is required before synergy becomes an accepted and utilized theory.Dr. Rand is interested in simulating distribution systems using alternative disinfection strategies to further the research on synergistic effects using bench-scale equipment.  Annular reactors (ARs) are widely accepted in the drinking water industry as a tool to simulate distribution systems due to their unique ability to promote biofilm formation while independently controlling hydraulic retention time and shear stress.  Collimated UV beams are an efficient way to achieve accurate dosages, and no such equipment currently exists in Atlantic Canada.