Photon energy produced by an ultraviolet (UV) light source is a powerful force with various applications in the field of water treatment. UV energy is transmitted in the form of light waves which appear on the electromagnetic spectrum between visible light and x-ray energy. Historically, UV technology has been most widely applied in the field of water treatment in the 254 nanometer (nm) wavelength for purposes of disinfection of water supplies. UV energy at 254 nm has been proven highly effective against bacteria as light energy interferes with the DNA structure of the organism, impairing its ability to reproduce. In addition to traditional disinfection applications, UV energy is also highly effective in breaking chemical bonds which bind molecules together. Therefore, UV energy is highly effective for destruction of organic compounds, ozone, chlorine, and chloramines within water supplies. Application of UV for destruction of these and various other compounds often found in water supplies is proliferating as proper UV light dosages and wavelengths are determined and empirically verified.
The use of UV for treatment of water supplies has several significant advantages over many other treatment technologies. Most notably, UV light energy does not add chemical compounds to the water supply which can impact taste, flavor, odor, color or pH of the water. Also, UV light energy does not generate harmful byproducts such as trihalomethanes (THMs) which are associated with the use of chlorine. Properly controlled light energy from UV systems is powerful, effective, fast-acting and environmentally friendly, particularly as compared to alternative water treatment technologies.
Dechlorination using UV light energy is one relatively new and exciting application of UV technology. Specifically, UV light applied at many times disinfection dosage has been proven to destroy free chlorine. UV light is also capable of destroying chloramine compounds, although the required dosage is significantly increased. The use of UV for dechlorination is particularly valuable for the electronics, pharmaceutical and beverage industries where bacterial control is imperative. UV dechlorination has several advantages over the use of activated carbon for dechlorination. First, bacterial colonization of activated carbon units is well documented and elimination of activated carbon units eliminates a significant venue for the growth of bacteria in a water system. Second, substituting UV dechlorination technology for activated carbon also affords the added benefit of a strong disinfection dosage during the dechlorination process. Disinfection of the water supply during the dechlorination process is a particularly valuable benefit where a downstream treatment unit such as a reverse osmosis processor is provided added protection from bio-fouling.
Watersolve offers conventional, quartz-sleeve UV technology in both 254 nm and 185 nm wavelengths, and with both low pressure and medium pressure lamps. Please contact the Watersolve factory for assistance with selection of the appropriate UV technology for a specific application. Examples of conventional, quartz-sleeve UV technology are as follows.
Sanitron Series for commercial applications. System features include a manual quartz sleeve wiper assembly, chamber housing constructed of 304 stainless steel, and polycarbonate sight port. Optional equipment includes UV monitor, elapsed run time indicator, time delay mechanism, wall mounting kit, and audio alarm. Available in flow rates from 2 GPM to hundreds of gallons per minute.
CSL Series with low-pressure lamp output designed for industrial, commercial and municipal application. System features include compact, one-piece design with 316L stainless steel treatment chamber and 304 stainless steel cabinet housing. Eleven standard models for UV disinfection in flow rates from 40 GPM to 520 GPM (on clear, fresh water), with TOC reduction and ozone destruction configurations also available. Optional equipment for the CSL Series includes UV sensor, 4-20 mA output, temperature safety control, and lamp out alert circuit. Similar system designs are also available for alternate flow rates and system applications, including UV dechlorination and applications requiring sanitary system design.
Medium-pressure arc tube systems are also available for disinfection, TOC destruction, and dechlorination applications in flow rates from 6 GPM to thousands of gallons per minute. Please contact the Watersolve factory for application-specific assistance.
TEFLON-COIL ULTRAVIOLET (UV) SYSTEMS
Beyond conventional UV technology, Watersolve has developed a Teflon-coil UV system which offers significant advantages over traditional quartz sleeve UV systems. Teflon, an extremely inert material, neither reacts with constituents contained in water nor imparts any constituents into the water, it has the lowest coefficient of friction of any solid material, it is highly resistant to degradation from UV light, and it is tolerant of temperatures from -275 F. to 500 F.
Of special note, Teflon's non-stick properties ensure that constituents of the water supply passing through Teflon tubing will not be deposited on its surface. This allows for consistent transmission of UV rays without cleaning. This distinguishes Teflon coil UV systems from traditional quartz tube systems which require frequent cleaning and which may suffer performance decline from degradation of UV transmission due to deposits on the quartz surface.
The coil configuration of the Teflon tubing around the UV bulb ensures that all water passes through the highest intensity UV zone, ensuring that the water is evenly dosed with UV rays and providing the highest possible kill rate through the complete water path. Also, the turbulent flow within the coiled tubing prevents shadowing which can block the transmission of UV rays to a particular organism and lower the effective kill rate.
Coils are available in 2 GPM to 5 GPM windings, with Teflon coil UV systems available in sizes from 5 GPM to hundreds of GPM.
Media filtration followed by eight, five GPM Teflon coils. System includes a chlorine injection system for addition of residual disinfectant.
Low-flow Teflon-coil unit designed for laboratory application. Units are available with Teflon/PVDF/PFA for all wetted surfaces.
UV disinfection up-stream of a compact reverse osmosis processor. UV pre-treatment results in significantly reduced bio-fouling potential of the RO membranes, resulting in reduced membrane cleaning requirements and enhanced long-term RO system performance.