Applications for Ultraviolet Water Purification

by Ann M. Wysocki, Marketing Director of Atlantic Ultraviolet

Ultraviolet water purification is a unique and rapid technique to rid water of bacteria, mold, virus and algae without the use of heat or chemicals. This method of water disinfection is ideal for many applications because nothing is added to the water. In addition to excellent disinfection performance, this process is simple, inexpensive, requires low maintenance and is more reliable when compared to other methods of water disinfection.

HOW IT WORKS
1. The water enters the purifier and flows into the annular space between the quartz sleeve and the chamber wall.
2. The wiper segments induce turbulence in the flowing liquid to insure uniform exposure of suspended microorganisms to the lethal ultraviolet rays.
3. The sight port enables visual observation of lamp operation.
4. The wiper assembly facilitates periodic cleansing of the quartz sleeve without any disassembly or interruption of purifier operation.
5. Water leaving the purifier is instantly ready for use.

ADVANTAGES OF THE ULTRAVIOLET METHOD
Effective - All microorganisms are susceptible to ultraviolet disinfection.
Economical - Hundreds of gallons can be purified for each penny of operating cost.
Safe - No danger of overdosing, no addition of dangerous chemicals.
Fast - Water is ready for use as soon as it leaves the purifier - no further contact time is required.
Easy - Simple installation and maintenance. Compact units require minimum space.
Automatic - Provides continuous or intermittent disinfection without special attention or measurement.
No Chemicals - No chlorine taste or corrosion problems.

APPLICATIONS
• Farms and Ranches: Bacteria free animal drinking water increases production by eliminating losses due to water-borne infection. Improved sanitation promotes healthier stock and higher yields.
• Water Wells: Eliminates bacteria which may build up from time to time from seepage of surface water or sewage.
• Bottling Manufacture: Insures bacteria-free water for use in product at breweries, wineries, soft drink and water bottling facilities.
• Pharmaceutical and Cosmetic Industries: Bacteria-free water insures compliance with strict water treatment standards necessary for product quality control.
• Laboratories: Provides ultrapure water required for accurate testing and research.
• Hospitals: Insures ultrapure water for pathology labs, kidney dialysis and post disinfection rinses where bacteria-free water is essential.
• Electronics Industry: Insures bacteria-free water for use in conjunction with deionized and high purity water systems.
• Food Industries: Insures bacteria- free water as an additive to product and also as a rinse before packaging to guard against waterborne bacteria spoilage in vegetables, fruits, meats, fish and other products.
• Private Homes, Trailer Parks, Recreation Vehicles, Schools, Hotels, Airplanes: Provides safe, germ-free drinking water. Destroying bacteria, a serious problem for rural water supplies, prevents disease.
• Aquariums and Hatcheries: Bacteria-free water prevents disease organisms from growing or spreading without producing by-products toxic to marine life.
• Wastewater Treatment Plants: Affords an excellent post water treatment of secondary effluent to reduce bacterial concentrations to safe levels without introducing a toxicant to fish and other marine life in the receiving waters.
• Nurseries: Bacteria-free water minimizes losses from widespread root rot infection, a common problem in trees and plants caused by a diseased water supply.
• Swimming Pools: Helps control bacteria, algae and slime formation. Ultraviolet water purification allows the user to substantially reduce the chlorine usage.
In 1966 the Dept. of Health, Education & Welfare, Public Health Service, Division of Environmental Engineering and Food Protection, released a Policy Statement on the use of ultraviolet for disinfection of water. According to the Public Health Service "The use of the ultraviolet process as a means of disinfecting water to meet the bacteriological requirements of the Public Health Drinking Water Standards is acceptable provided the equipment used meets the listed criteria."

Criteria for the Acceptability of an Ultraviolet Disinfecting Unit
1. Ultraviolet radiation at a level of 2,537 Angstrom units must be applied at a minimum dosage of 16,000 micro-watt-seconds per square centimeter at all points throughout the water disinfection chamber.
2. Maximum water depth in the chamber, measured from the tube surface to the chamber wall, shall not exceed three inches.
3. The ultraviolet tubes shall be:a.) Jacketed so that a proper operating tube temperature of about 105 Degrees Fahrenheit is maintained, and b.) The jacket shall be of quartz or high silica glass with similar optical characteristics.
4. A flow or time delay mechanism shall be provided to permit a two-minute tube warm-up period before water flows from the unit.
5. The unit shall be designed to permit frequent mechanical cleaning of the water contact surface of the jacket without disassembly of the unit.
6. An automatic flow control valve, accurate within the expected pressure range, shall be installed to restrict flow to the maximum design flow of the treatment unit.
7. An accurately calibrated ultraviolet intensity meter, properly filtered to restrict its sensitivity to the disinfection spectrum shall be installed in the wall of the disinfection chamber at the point of greatest water depth from the tube or tubes.
8. A flow diversion valve or automatic shut-off valve shall be installed which will permit flow into
the potable water system only when at least the minimum ultraviolet dosage is applied. When power is not being supplied to the unit, the valve should be in a closed (fail safe) position, which prevents the flow of water into the potable water system.
9. An automatic audible alarm shall be installed to warn of malfunction or impending shutdown if considered necessary by the Control or Regulatory Agency.
10. The materials of construction shall not impart toxic materials into the water either as a result of the presence of toxic constituents in materials of construction or as result of physical or chemical changes resulting from exposure to ultraviolet energy.
11. The unit shall be designed to protect the operator against electrical shock or excessive radiation. As with any potable water treatment process, due consideration must be given to the reliability, economics, and competent operation of the disinfection process and related equipment, including:

1. Installation of the unit in a protected enclosure not subject to extremes of temperature which could cause malfunction.
2. Provision of a spare UV tube and other necessary equipment to effect prompt repair by qualified personnel properly instructed in the operation and maintenance of the equipment.
3. Frequent inspection of the unit and keeping a record of all operations, including maintenance problems. As a minimum, the initial purchase of an ultraviolet water purifier should include a mechanical wiper mechanism to insure compliance with the Federal Guidelines. It is important to note that many ultraviolet water purifiers on the market today are not equipped with a wiper feature making compliance impossible as this feature cannot be retrofitted later on, as other accessories required in the guidelines can.
The wiper allows the user to clean the quartz (a critical component of the system as it houses the germicidal lamp) without shutdown or disassembly of the unit and insures the user maximum effectiveness from the lamp since cleaning of the quartz sleeve can be done on routine basis with the pull of the knob.

Reprinted by Permission from Water Conditioning Magazine.


Atlantic Ultraviolet Corporation
375 Marcus Blvd.Hauppauge, NY 11788
http://www.ultraviolet.com
info@ultraviolet.com
631-273-0500
Fax: 631-273-0771