Silvestry-Rodriguez Nadia, Bright Kelly R, Uhlmann Donald R, Slack Donald C, Gerba Charles P
Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, Arizona, USA.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2007 Sep;42(11):1579-84. doi: 10.1080/10934520701517689.
This study was conducted to assess the efficacy of silver as a secondary disinfectant to replace or reduce the level of chlorine utilized in water distribution systems. Pseudomonas aeruginosa and Aeromonas hydrophila are opportunistic pathogens present in drinking water and have been associated with waterborne disease. After 8 hours of exposure to 100 microg/L of silver, there was a >6-log10 reduction in P. aeruginosa in tap water at room temperature at pH7 and a 5.55-log10 reduction in the presence of 3 mg/L humic acid. Similar reductions were observed at pH9. At 4 degrees C, reductions greater than 4-log10 were observed after 24 hours. For A. hydrophila, a >6-log10 reduction occurred at both pH7 and pH9 within nine hours. The World Health Organization has determined that this amount of silver could be used for water disinfection without health risks. Furthermore, silver shows promise as a secondary disinfectant, even in the presence of organic matter in concentrations that would reduce the effectiveness of free chlorine.
本研究旨在评估银作为二级消毒剂替代或降低配水系统中氯使用水平的效果。铜绿假单胞菌和嗜水气单胞菌是饮用水中存在的机会致病菌，与水源性疾病有关。在室温pH7条件下，自来水暴露于100μg/L银8小时后，铜绿假单胞菌数量减少>6个对数级；在存在3mg/L腐殖酸的情况下，减少5.55个对数级。在pH9时也观察到类似的减少。在4℃时，24小时后减少量大于4个对数级。对于嗜水气单胞菌，在pH7和pH9时，9小时内数量减少>6个对数级。世界卫生组织已确定该量的银可用于水消毒且无健康风险。此外，即使存在会降低游离氯有效性的有机物，银作为二级消毒剂也显示出前景。
