Frequently Asked Questions

UV Disinfection

How does UV disinfection work?

UV light interacts with the DNA of bacteria; viruses; and giardia and cryptosporidium occysts causing dimerization of adjacent thymine portions of the DNA. Once sufficient damage has been done to the DNA, the organisms can no longer reproduce and are therefore no longer infectious.

What are typical applications for UV disinfection?

The two largest applications for UV disinfection are drinking water and wastewater. As a result of Calgon Carbon’s groundbreaking research, the use of UV disinfection has won approval from the USEPA for the inactivation of cryptosporidium and giardia in drinking water. The elimination of chlorine use is one of the drivers in the wastewater market.

How is UV light generated for disinfection?

The most common way to generate UV light for disinfection is through the use of mercury vapor lamps. There are several types of mercury vapor lamps such as medium-pressure, low-pressure, and amalgam lamps. The choice of lamps depends on the specific application.

Are there ways to model the UV systems for my application?

For disinfection applications, a dose or log inactivation can typically be assured because of extensive third-party system validation. If needed, computational fluid dynamics (CFD) modeling can be used to bridge a suppliers validation to your specific layout.

Can we conduct a pilot test of the UV system before I buy one?

Pilot testing is available. Please contact your Regional Sales Manager to discuss the details.

What type of flow rates can be treated?

A wide range of flow rates can be treated. Depending on the specific application, individual UV disinfection systems can treat from a few hundred gallons per minute up to 40 million gallon per day. Multiple units can and are often used in parallel to achieve higher overall treatment volumes.

How much operator attention will be required?

Operator attention is generally minimal. With the inclusion of automatic cleaning systems on all of Calgon Carbon’s systems, maintenance involves changing UV lamps at regular intervals.

UV Oxidation

What is UV oxidation and how does it work?

UV oxidation utilizes hydroxyl radicals generated from the interaction of UV light with either hydrogen peroxide or ozone to oxidize a wide variety of organic compounds. Hydroxyl radicals are one of the most powerful oxidizing agent know and have the ability to destroy a wide variety of compounds.

What types of compounds are destroyed by UV oxidation?

Many contaminants can be treated with UV oxidation. The most common applications include NDMA, dioxane, chlorinated organic compounds, taste and odor compounds, BOD and COD.

Can UV oxidation be combined with other treatment technologies?

UV oxidation can be combined with other treatment schemes such as activated carbon adsorption, air stripping, etc. to result in a total system solution.

What types of flow rates can be treated?

The flow rates that can be treated vary with the application and treatment objective. Contact your Regional Sales Manager for more information.


What background compounds in the water do I need to be concerned about?

Several water constituents need to be taken into account when properly sizing a UV oxidation system. These include among others, compounds which strongly absorb UV radiation, nitrate and carbonate.

For more information on UV disinfection and oxidation applications, please call 724-218-7000 or e-mail info@calgoncarbon-us.com