New improvements in ultraviolet sterilization of desalted and reuse water

Abstract

Ultraviolet water sterilization inherently has the advantage that it adds nothing and does not change the chemical composition Of the fluid. However, the process has not been widely used because of operation and maintenance problems linked to quartz tubes which separate the ultraviolet source from the water. The Ultraviolet Technology, Inc. (UTI) process overcomes these problems by using ultraviolet transmitting fluorocarbon tubes to contain the water during sterilization. The fluorocarbon tubes are chemically inert, non-wetting, and resistant to fouling, USFDA approved for drinking water, and stable to ultraviolet as demonstrated in a 15 year exposure test. Commercial installations have been in continuous operations on turbid seawater for over 3 years without any need for cleaning. The largest plant in operation has a capacity of 1.3 MGD. Capital costs with the UTI process are less than 1 2 those of quartz tubes ultraviolet sterilizers. Operating costs are typically less than 1 cent per 1,000 gallons.