Orion Environmental Inc. and Applied Process Technology, Inc. announce the installation and startup of an innovative groundwater treatment process for destruction of 1,4-dioxane at a pump-and-treat project in southern California. Orion selected Applied Process Technology, Inc.'s HiPOx Advanced Oxidation Process, or AOP, technology to retrofit this groundwater treatment project. During the last five years, an air stripping system treated chlorinated solvents (DCA, DCE, PCE, TCA, and TCE) at the site. When the State of California added 1,4-dioxane to its "emerging contaminants list" and began requiring analysis for the compound, Orion found 1,4-dioxane concentrations of over 500 ppb.
1,4-dioxane is one of the most difficult-to-treat toxic contaminants found in groundwater and subsurface environments. A high-volume ether chemical used as a stabilizer, 1,4-dioxane appears at sites where common chlorinated degreasing solvents like TCA and TCE are present. It is very miscible in water and does not biodegrade. Therefore, it moves quickly through aquifers, threatening neighboring water sources. Until recently, detection of 1,4-dioxane was difficult at lower concentrations because of limitations in analytical techniques. As laboratory analysis has improved, the number of 1,4-dioxane detections has been increasing.
Because neither air stripping nor carbon treatment removes 1,4-dioxane, Orion and Applied sized a 70-gpm HiPOx unit to operate at the site. Applied's pilot test showed that placement of the HiPOx unit ahead of the existing air stripping system would be most cost-effective. With this placement, HiPOx destroys the 1,4-dioxane to less than 2 ppb plus over 99 percent of the DCE, PCE, and TCE in the contaminated water. The existing air stripping system now operates with much lower loading, having only to remove the remaining DCA and TCA.
For more information, call Michael Purchase, Orion (562) 988-2755, or Chuck Borg, Applied (925) 977-1811, extension 206.