Ex Situ Treatment of MTBE-Containing Groundwater by a UV Peroxide System

This article describes the design, implementation, and operating results for an ex situ ultraviolet/hydrogen peroxide (UVP) system to treat methyl tert-butyl ether (MTBE) in extracted groundwater. The UVP modification was designed to reduce the operation and maintenance costs of an existing groundwater pump-and-treat treatment system that relied on air stripping and carbon adsorption. The UVP system is relatively inexpensive and can easily be scaled to cope with different groundwater extraction rates up to 80 gpm by adding UV lamps in series or in parallel at the higher groundwater extraction rates. The MTBE concentration in the effluent from the UVP system to the carbon vessels decreased from an average of 590 µg/L to approximately 2 µg/L on average over 33 months of operation of the UVP. Incorporation of this UVP modification as a second-stage treatment to the groundwater pump-and-treat/soil vapor extraction system, after the air stripper and prior to the carbon vessels, significantly increased the usable life of the carbon (from two months previously to about two years after installation) and completely resolved the issue of frequent MTBE breakthroughs of the carbon that had plagued the remediation system since its inception. © 2006 Wiley Periodicals, Inc.