UV treatment keeps bacteria out of wastewater receiving stream

When selecting equipment for a new wastewater treatment facility, the City of Fairfield, Ohio, wanted a non-chemical solution for the final disinfection of its treated wastewater.

ERLANGERr, Ky., March 23, 2004 -- When selecting equipment for a new wastewater treatment facility, the City of Fairfield, Ohio, wanted a non-chemical solution for the final disinfection of its treated wastewater.

The city chose In-Line Ultraviolet (UV) systems from wastewater and effluent re-use disinfection specialist, Aquionics. The closed vessel, medium pressure systems destroy fecal colliform bacteria in the plant's effluent stream before it is discharged to the Great Miami River.

Two In-Line systems were installed at the Fairfield Wastewater Treatment facility in April 2003 to handle a flow capacity of 15 million gallons per day (mgpd) during Ohio's disinfection season of May to October. Since installing the systems, the facility has realized treatment levels well within the limits specified by their NPDES permit for fecal coliform bacteria.

The two UV chambers deliver a dose of high-energy, medium-pressure UV disinfection, with fewer lamps than comparable low pressure, open-channel systems. This compact design significantly reduced the installation space requirements.

The UV system is simple to operate, leaves no chlorine residual in the treated water and doesn't require the use and storage of dangerous chemicals. According to plant Chief Operator, Bradley Abner, the ability to operate without using chlorine for disinfection is one of the greatest benefits of the new system.

Also an important consideration for the City of Fairfield was the minimal headloss provided by the system's closed chamber design. "We had a minimal amount of head available in this project," explains Drew Young, Superintendent, City of Fairfield WWTP. "We reviewed several competitive systems and the head loss for the Aquionics unit was about 60% of the other units."

The systems feature Aquionics' new UVTronic™ plc controls for ease of operation and reliability. This control unit records up to 12 months of operational data for record keeping and analysis with discrete fault alarms aid in diagnosis of performance problems. The controller can be fitted with a modem connection to perform remote diagnostics on the system for fast troubleshooting with minimal service interruption.

The In-Line is equipped with an automatic self-cleaning mechanism to remove organic deposits from the quartz sleeves for consistent performance with little maintenance. UV lamp life is expected to be 8000 hours, resulting in a four-year life cycle at the plant's daily flow rate of 5.3 mgpd.

Aquionics is a provider of UV technology for progressive, non-chemical disinfection and microbiological control. A member of the worldwide Halma group, the company offers unparalleled experience in the manufacture, application, and development of UV equipment. For more information about Aquionics and its family of products, visit their website at www.aquionics.com or call their offices at 800-925-0440.

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