Ultraviolet (UV) Oxidation

Description

Ultraviolet (UV) oxidation is a destruction process that oxidizes organic contaminants in water. It works by the adding oxidizing agents such as ozone (O₃) or hydrogen peroxide (H₂O₂) to the contaminated groundwater. The contaminated solution is passed through a chamber where it is exposed to intense UV radiation. UV radiation is provided by UV light bulbs Oxidation of target contaminants is caused by direct reaction with the oxidizers (for example, see description of Peroxone), and through the action of UV light in combination with ozone and/or hydrogen peroxide.

Limitations and Concerns

A major success factor is how well UV light is transmitted to dissolved contaminants. High turbidity (e.g., cloudiness) of the water would cause interference.

The water should be relatively free of heavy metal ions and insoluble oil or grease to minimize the potential for fouling of the lights.

This system does not destroy some volatile organics such as trichloroethane (TCA). Instead, the contaminants may be vaporized and would need to be treated in an off-gas system.

Energy requirements are very high, and this is a large drawback to this technology.

Handling and storage of hydrogen peroxide requires special safety precautions.

Applicability

UV treatment is used to destroy VOCs and UXO (explosive compounds such as TNT) in groundwater. Typically, easily oxidized organic compounds, such as those with double bonds (e.g., TCE, PCE, and vinyl chloride), as well as simple aromatic compounds (e.g., toluene, benzene, xylene, and phenol) are rapidly destroyed in UV/oxidation processes. UV Oxidation can also be used to treat organic compounds in air treatment systems.

Technology Development Status

The UV/oxidation technology is a commercially available groundwater treatment technology that has been used for more than 10 years. A majority of these applications are for groundwater contaminated with petroleum products or with a variety of industrial solvent-related organics such as TCE, DCE, and vinyl chloride. Its use for destroying explosive compounds has been more limited. The US Army Environmental Center (AEC) evaluations have shown it to be 99.9% effective in destroying common explosives in groundwater.

Web Links

http://www.frtr.gov/matrix2/section4/4-45.html

http://www.frtr.gov/matrix2/section4/4-59.html

http://www.cluin.org/download/toolkit/uvox_o.pdf

Other resources

None have been identified. See description of Vapor Phase Oxidation.