Loss of chlorine, chloramine or chlorine dioxide concentration following exposure to UV light

Abstract

Research Article| March 01 2008 Loss of chlorine, chloramine or chlorine dioxide concentration following exposure to UV light Jennie L. Rand; Jennie L. Rand 1Ivan Curry School of Engineering, Acadia University, Wolfville, NS, B4P 2R6, Canada Search for other works by this author on: This Site PubMed Google Scholar Graham A. Gagnon Graham A. Gagnon 2Department of Civil & Resource Engineering, Dalhousie University, Halifax, NS, B3J 1Z1, Canada E-mail: graham.gagnon@dal.ca Search for other works by this author on: This Site PubMed Google Scholar Journal of Water Supply: Research and Technology-Aqua (2008) 57 (2): 127–132. https://doi.org/10.2166/aqua.2008.027 Article history Received: April 17 2007 Accepted: June 07 2007 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Cite Icon Cite Permissions Search Site Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsThis Journal Search Advanced Search Citation Jennie L. Rand, Graham A. Gagnon; Loss of chlorine, chloramine or chlorine dioxide concentration following exposure to UV light. Journal of Water Supply: Research and Technology-Aqua 1 March 2008; 57 (2): 127–132. doi: https://doi.org/10.2166/aqua.2008.027 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex In a field study conducted previously in Pinellas County, Florida, implementing UV treatment following chemical disinfection hindered control of HPC bacteria and resulted in higher counts in most samples. It was believed that free chlorine and monochloramine were either decaying in the presence of UV light or that they were absorbing UV irradiation. These occurrences would both lead to a decrease in available disinfection and in turn lead to increased bacteria counts. A bench-scale study was conducted to further investigate interactions between UV light and chemical residuals in drinking water. Three separate water sources (surface water, blended water and deionized water) were treated with chlorine, monochloramine or chlorine dioxide at different concentrations, then exposed to low-pressure UV light. It was confirmed that chemical disinfectants decay when samples are exposed to UV light. Specifically, for deionized water free chlorine was lowered to approximately 95% of initial concentration following UV treatment. In contrast, free chlorine was decreased to 89% and 84%, on average, in the tested groundwater and surface water, respectively. A similar range in decreased disinfectant concentration was also observed for chlorine dioxide and chloramines. However, no significant absorption of UV irradiation by chemical disinfectants was observed. These results provide greater insight into the confounding effects between chlorine-based disinfectants and UV light, which may be important for utilities or institutions that are considering UV treatment of previously disinfected water. chloramines, chlorine, chlorine dioxide, disinfection, UV disinfection This content is only available as a PDF. © IWA Publishing 2008 You do not currently have access to this content.