Charlotte, NC, Oct. 3, 2002 -- WEDECO-Ideal Horizons, an ultraviolet disinfection systems manufacturer, has been selected by the City of Auburndale, Florida to supply a TAK-55 UV system for the Raymond Allred WWTP to treat wastewater for reuse as cooling water at a local energy center.
WEDECO-Ideal Horizons was selected by Auburndale due to their experience in and UV technology of disinfecting wastewater. A very important aspect in the evaluation was also WEDECO-Ideal Horizons being the first and so far the only UV manufacturer who has received conditional approval by the California DHS (Department of Health Services) and Hawaiian DOH (Department of Health) for the TAK-55 UV system for the disinfection of filtered wastewater for water recycling.
In California the Water Recycling Criteria - internationally known as Title-22 - requires disinfected filtered reclaimed water to be essentially pathogen-free. Treated effluent meeting these stringent microbiological standards can be used for cooling water, irrigation of food crops, parks, playgrounds, golf courses, etc.
Chastain Skillman of Lakeland, Florida, leading consulting engineers in water treatment plant design, worked extensively with the engineers at the Allred WWTP and WEDECO to provide the best solution for their needs.
As Florida's population continues to grow by about 4,500 persons each week, the demand for fresh, clean water also increases - a fact that is leading to more widespread, severe, and more prolonged, water shortages. Nearly 75 percent of the 15 million people in Florida live close to the coast, and the population growth continues to center on coastal areas.
Near the coast, ground water supplies are limited, shallow, and vulnerable to overdraft, contamination, and salt-water intrusion. Reuse is helping conserve potable water supplies since reclaimed water is used in place of potable water for certain purposes. In addition, many reuse activities can help recharge ground water supplies.
Ultraviolet technology provides a proven, accepted and environmentally friendly method of disinfecting wastewater. When exposed to UV-C light, microorganisms are inactivated within seconds through a physical reaction with the organisms' DNA. In contrast to chemical disinfection, UV produces no harmful by-products. It also eliminates the risk to operators associated with handling dangerous chemicals.
Two major advantages of UV disinfection versus chemical methods are increased disinfection effectiveness (especially against viruses) as well as space-savings due to shorter reaction times. Since no chemicals are introduced into the water, no "post-treatment" is required to remove these chemicals before discharge to the environment or for secondary use elsewhere.
The WEDECO TAK55 UV system for the Allred WWTP is designed to treat a flow rate of 2 MGD (315.5 m3/h). In order to meet the NWRI/AWWARF guidelines for wastewater reuse, WEDECO designed the system to deliver a UV dose of 100 mJ/cm2.
The 5-bank, 2 channel system (4-banks duty, 1 stand-by) utilizes proprietary Spektrotherm® low-pressure high-intensity lamps. These highly effective lamps emit more than 95% of the UV energy produced at the single wavelength of 254 nm.
A single Spektrotherm® Lo-Hi lamp will deliver four to five times more UV energy that a typical low-pressure mercury lamp while maintaining the same electrical efficiency. The results are fewer lamps required versus competitors, reduced design/construction costs, savings in operating and maintenance and lower installation costs.
One of the most important features in state-of-the-art UV systems is automatic cleaning to keep the equipment performing day-in and day-out. The TAK automatic wiping system performs this function like no other. Employing specially designed wiper rings, it prevents organic and inorganic deposits from accumulating on the lamp protective quartz tubes. This ensures that the UV light consistently reaches all microorganisms within the effluent.
The UV intensity to which an organism is exposed is dependent on the lamp output, quartz tube cleanliness and effluent UV transmittance. By using dedicated UV sensors mounted within the lamp arrays, each of these variables is automatically incorporated into the measured intensity value. Another factor in designing the UV system for the Allred WWTP was the water quality and determining a way to monitor it.
Of particular importance is the UV transmittance, or the ability of the UV light to pass through the water, which is to be disinfected. To measure the UV transmittance at the Allred WWTP, WEDECO will provide their patented HIPPO transmittance monitor specifically for measurement in wastewater. The HIPPO is specially designed for continuous on-line monitoring of UV transmittance at 254 nm during system operation.
The HIPPO consists of a measuring device, which is partially immersed in the effluent, and a separate control box with display, so that the Allred WWTP engineers can constantly monitor the water quality.
John Marrino, WEDECO-Ideal Horizon's president said, "We are thrilled to have been selected by the City of Auburndale to provide this system. UV continues to play an increasingly important role in wastewater reuse. Many wastewater treatment plants are beginning to evaluate and implement alternative disinfection methods, with UV disinfection technology among the most popular. UV has long been recognized as an effective disinfectant. However, unlike chlorine, UV does not pose disinfection byproducts, toxicity, or hazardous materials concerns."
John added, "Our TAK-55 system represents state-of-the-art in terms of reliability and performance. The Allred WWTP will continue to benefit long after the system is commissioned as a result of the lower operating, maintenance costs and of course consistently disinfected water."
WEDECO-Ideal Horizons is a member of the WEDECO AG - a supplier of UV systems worldwide with more than 200,000 delivered units.
For more information, visit http://www.pci-wedeco.com.
