Makuei Mehrnaz Soleimanpour, Peleato Nicolas
Department of Civil Engineering, University of British Columbia, Okanagan, Canada.
Sci Rep. 2025 May 22;15(1):17798. doi: 10.1038/s41598-025-01101-3.
The performance of ultraviolet (UV) disinfection is subject to the quality of water supplied to the reactor, which could often be poor in facilities lacking adequate pre-treatment. Particulate matter in low-quality water can interfere UV disinfection by shielding microorganisms from light through particle-microorganism (p-m) associations. This study investigates Zeta Potential (ZP) manipulation as a pre-treatment to improve UV effectiveness by reducing p-m associations. ZP manipulation is hypothesized to free microorganisms from particulate attachments, increasing their UV vulnerability. Water samples from a drinking water treatment plant applying UV disinfection without pre-filtration were altered for ZP, achieving five different ZP levels. A protocol was developed to distinguish between viable microorganisms attached to particles and free-floating microorganisms. UV experiments were conducted to establish the relationship between UV efficiency and ZP. Results indicated that neutral ZP results in the highest p-m association and lowest disinfection achieved. Disinfection kinetic studies revealed that highly negative ZP enhanced UV efficiency as delivered UV dose increased due to dominant repulsive forces. This study demonstrated that optimizing ZP effectively controlled the degree of p-m association for both viruses and bacteria, which could be a viable approach for mitigating p-m association and leveraged for advancements in UV disinfection.
紫外线（UV）消毒的效果取决于供应给反应器的水质，在缺乏充分预处理的设施中，水质往往较差。低质量水中的颗粒物会通过颗粒-微生物（p-m）结合，遮挡微生物使其免受光照，从而干扰紫外线消毒。本研究探讨了通过操纵zeta电位（ZP）作为预处理手段，减少p-m结合，以提高紫外线消毒效果。据推测，操纵ZP可使微生物从颗粒附着物上脱离，增加其对紫外线的敏感性。对一家未进行预过滤而采用紫外线消毒的饮用水处理厂采集的水样进行了ZP改变处理，实现了五种不同的ZP水平。制定了一个方案，以区分附着在颗粒上的活微生物和自由漂浮的微生物。进行了紫外线实验，以确定紫外线效率与ZP之间的关系。结果表明，中性ZP导致最高的p-m结合和最低的消毒效果。消毒动力学研究表明，由于主要的排斥力，随着紫外线剂量的增加，高度负的ZP提高了紫外线效率。本研究表明，优化ZP可有效控制病毒和细菌的p-m结合程度，这可能是减轻p-m结合的可行方法，并可用于推动紫外线消毒技术的进步。
