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

控制分配系统中的微生物再生是饮用水工业公用事业的主要问题之一。在管道表面形成细菌簇或“生物膜”可导致致病微生物增加，管道材料的生物腐蚀和管道系统的headloss。消毒通常是控制管道系统生物污染的关键步骤。由于对消毒剂及其副产品的法规越来越严格（即USEPA II阶段D/DBP规则），供应商正在努力保持残留保护，控制生物膜形成和遵守饮用水标准之间的平衡。这似乎是合理的消毒剂组合可以形成一个综合的消毒策略，加强微生物病原体的去除进入配送系统。虽然该领域的研究有限，但兰德博士进行的初步研究表明，紫外线和含氯消毒剂在减少大量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在不增加化学消毒剂剂量的情况下实现更高的细菌去除率，从而从协同作用中受益。然而，在协同作用成为一种被接受和应用的理论之前，还需要进行更多的研究。兰德对使用替代消毒策略模拟分配系统感兴趣，以进一步研究使用实验规模设备的协同效应。环形反应器（ARs）由于其独特的促进生物膜形成的能力，同时独立控制水力停留时间和剪切应力，在饮用水工业中被广泛接受为模拟分配系统的工具。准直紫外线光束是获得精确剂量的有效方法，目前在加拿大大西洋地区还没有这样的设备。

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.