title: Assessment of a low-cost, point-of-use, ultraviolet water disinfection technology.
abstract: We describe a point-of-use (POU) ultraviolet (UV) disinfection technology, the UV Tube, which can be made with locally available resources around the world for under $50 US. Laboratory and field studies were conducted to characterize the UV Tube's performance when treating a flowrate of 5 L/min. Based on biological assays with MS2 coliphage, the UV Tube delivered an average fluence of 900+/-80 J/m(2) (95% CI) in water with an absorption coefficient of 0.01 cm(-1). The residence time distribution in the UV Tube was characterized as plug flow with dispersion (Peclet Number = 19.7) and a mean hydraulic residence time of 36 s. Undesirable compounds were leached or produced from UV Tubes constructed with unlined ABS, PVC, or a galvanized steel liner. Lining the PVC pipe with stainless steel, however, prevented production of regulated halogenated organics. A small field study in two rural communities in Baja California Sur demonstrated that the UV Tube reduced E. coli concentrations to less than 1/100 ml in 65 out of 70 samples. Based on these results, we conclude that the UV Tube is a promising technology for treating household drinking water at the point of use.
authors.affiliation: Sustainable Organic Integrated Livelihoods, Berkeley, CA, USA.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Brownell
authors.forename: Alicia R
authors.initials: AR
authors.lastname: Chakrabarti
authors.forename: Forest M
authors.initials: FM
authors.lastname: Kaser
authors.forename: Lloyd G
authors.initials: LG
authors.lastname: Connelly
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Peletz
authors.forename: Fermin
authors.initials: F
authors.lastname: Reygadas
authors.forename: Micah J
authors.initials: MJ
authors.lastname: Lang
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Kammen
authors.forename: Kara L
authors.initials: KL
authors.lastname: Nelson
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D002070:Butadienes / Q000737:chemistry; D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli; D017909:Levivirus / Q000528:radiation effects*; D008962:Models, Theoretical; D011137:Polystyrenes / Q000737:chemistry; D011143:Polyvinyl Chloride / Q000737:chemistry; D013232:Steel / Q000737:chemistry; D014466:Ultraviolet Rays; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
chemical_list: D000180:Acrylic Resins; D002070:Butadienes; D011137:Polystyrenes; D013232:Steel; D011143:Polyvinyl Chloride; C024636:ABS resin