Ultraviolet Light Disinfection in the Use of Individual Water Purification Devices

Abstract

PURPOSEThis information paper provides an in-depth review of ultraviolet (UV) light for use as a disinfection technology in potable water supplies. This paper is intended to assist the reader in evaluating the disinfection capabilities of UV light-using Individual Water Purification Devices (IWPDs) to inactivate disease-causing bacteria, viruses, and cysts. REFERENCESAppendix A contains a list of references. INTRODUCTION BackgroundUnderstanding the disinfection capabilities of UV light to inactivate disease-causing microorganisms is important in protecting Soldiers, who are considering using this technology, from acute health threats posed by these microorganisms. Soldiers deployed beyond traditional field drinking water supplies must have access to microbiologically safe water. Using IWPDs is one way to provide microbiologically safe water in these situations. These IWPDs must protect the Soldier from acute microbial health threats. The U.S. Environmental Protection Agency (EPA) Guide Standard and Protocol for Testing Microbiological Water Purifiers (reference 1) provides performance standards by which an IWPD that uses UV light can be evaluated. The performance standards are a minimum 6-log reduction/inactivation of bacteria, 4-log reduction/inactivation of viruses, and 3-log reduction/inactivation of protozoan cysts. UV-using IWPDs meeting these standards are considered effective against disease causing bacteria, viruses, and protozoan cysts. Some IWPD manufacturers test their devices using this protocol. This is the best way to evaluate the IWPDs disinfection capabilities. In the absence of that testing data, this information paper can be used to gain an understanding of UV light disinfection capabilities and help determine if an IWPD using UV light could successfully meet the EPA Guide's minimum performance standards. This information paper was developed primarily using information obtained from the EPA's Draft Ultraviolet Disinfection Guidance Manual (reference 2). The manual provides a comprehensive review of available scientific literature concerning UV disinfection in drinking water systems.b. History of UV Light in Potable Water Applications. The germicidal properties of UV light were discovered in 1887. The first application of UV light in drinking water occurred in Report Documentation PageForm Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing...

Ultraviolet germicidal irradiation in tap water contaminated by Aspergillus spp.

“…Our results confirm that 9 fungi belonging the Aspergillus genera , in particular A. flavus and A. niger , have a greater resistance to UV irradiation compared to other microorganisms, although the methodology used in our experiments is different from that proposed by other authors who employed continuous flow UV reactor testing or collimated beam testing [ 22 , 26-28 , 32 , 33 , 35 , 36 ]. Furthermore, higher resistance of A. flavus and A. niger is also described by other authors in tests conducted in water [ 23 ], whereas A. fumigatus showed the highest resistance in tests conducted in air [ 37 ].…”

“…Interest in using UV light treatment to disinfect drinking water is growing due to its ability to inactivate pathogenic micro-organisms without forming DBPs and its effectiveness against several pathogens that are resistant to commonly used disinfectants such as chlorine. Many investigations have been made to assess the dose of UV irradiation necessary for effective bacterial disinfection of drinking water [ 21 , 32 , 33 ], while less data are available concerning the effect of UV irradiation on fungi in potable water.…”

Advances in Ultraviolet Light Technology for Non-thermal Processing of Liquid Foods

“…Little information exists regarding the fate of mercury released to the water or liquid food product as a result of UV lamp breakage and potential health risks. Clarke (2006) indicated that the breakage of a UV lamp containing 150 mg mercury in a 50-L batch reactor resulted in a concentration of 2.5 μg/L of mercury in the reactor. However, it was not reported whether all 150 mg of mercury was recovered.…”

Occurrence and Control of Legionella in Recycled Water Systems

“…UV disinfection was not affected by temperature. UV efficacy was also independent of pH [ 103 ]. Legionella sp.…”