Assessment of ultraviolet disinfection for unfiltered water supplies

饮用水的紫外线消毒是一种有效且日益流行的灭活氯抗性病原体的方法。在加拿大，紫外线处理了超过21%的饮用水，最近对处理设施的调查表明，这项技术是提高消毒效果的首选。由于天然水中的微粒和其他物质会阻挡或反射光，从而干扰消毒过程，因此建议过滤后使用紫外线。然而，过滤并不是普遍实行的，一些未经过滤的水供应利用紫外线消毒。关于未经过滤的水的紫外线有效性的知识存在空白，为了保护公众健康，必须在一系列条件下充分了解其性能。

Ultraviolet (UV) disinfection of drinking water is an effective and increasingly popular method to inactivate chlorine-resistant pathogens of public health concern. In Canada, UV treats over 21% of all drinking water, and recent surveys of treatment facilities identify this technology as a top choice for increasing disinfection effectiveness. Since particulates and other material in natural waters can interfere with the disinfection process by blocking or reflecting light, it is recommended that UV be applied after filtration. However, filtration is not practiced universally, and several unfiltered water supplies utilize UV for disinfection. There are gaps in knowledge regarding UV effectiveness for unfiltered waters, and performance must be well understood under a range of conditions for the protection of public health. The proposed work aims to address knowledge gaps by quantifying relationships between a wide range of unfiltered water quality conditions and UV effectiveness. Two full-scale treatment facilities that apply UV to unfiltered waters will be used as models and to provide representative samples. Disinfection achieved will be identified through standardized microorganism bioassays after exposure to collimated UV light. Using experimental data, the adequacy of current monitoring and operational practices will be considered. This work will also look at ways to improve the accuracy of UV monitoring protocols to ensure that disinfection can be achieved even with challenging source water conditions. Project outcomes will include new data to advance industry best practices in UV disinfection of unfiltered water supplies at Canadian facilities.