title: Multiple-barrier disinfection by chlorination and UV irradiation for desalinated drinking waters: chlorine photolysis and accelerated lamp-sleeve fouling effects.
abstract: Experiments were conducted to quantify interaction effects between UV irradiation and chlorination for desalinated drinking water. The rate of chlorine photolysis in desalinated water was characterized using a low-pressure UV lamp and chlorine doses typical of drinking water treatment and was found to be lower than reported photolysis rates for treated surface water. Results indicate that, for most desalinated water applications, reduction in free chlorine is likely to be limited, but, depending on the UV dose used, not necessarily negligible. Investigation of the potential for reactor lamp-sleeve fouling included mineral speciation and solubility modeling and showed that chlorination of desalinated water before UV disinfection may increase lamp-sleeve fouling, particularly for point-of-use reactors. UV irradiation before chlorination may minimize fouling. Overall results point to the variable nature of UV lamp-sleeve fouling and chlorine photolysis and an intrinsic dependence on local water chemistry conditions.
authors.affiliation: American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates. iwait@aus.edu
authors.forename: Isaac W
authors.initials: IW
authors.lastname: Wait
mesh_terms: D002713:Chlorine / Q000737:chemistry* / Q000494:pharmacology; D004203:Disinfection / Q000295:instrumentation / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D004326:Drinking; D004866:Equipment Contamination; D010782:Photolysis; D012965:Sodium Chloride / Q000032:analysis / Q000302:isolation & purification*; D014466:Ultraviolet Rays; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*; D014881:Water Supply
chemical_list: D012965:Sodium Chloride; D002713:Chlorine