Abstract

The HiPOx technology is an advanced oxidation process that incorporates high-precision delivery of ozone and hydrogen peroxide in order to chemically destroy organic contaminants while minimizing bromate formation. Ground water contaminated with methyl tertiary butyl ether (MTBE) from the Ventura County Naval Base in Port Hueneme, California, was used to evaluate this technology.

Due to extremely high concentrations (1.3 milligrams per liter [mg/L]) of bromide in the feed water and the desire to limit bromate formation, an experimental system was operated with 630 ozone injector ports in series. In all trials, the HiPOx system reduced MTBE from 748 grams per liter (g/L) to below its regulatory limit of 5 g/L. However, bromate was not maintained below its regulatory limit of 10 g/L. Both MTBE and bromate were under their regulatory limits at intermediate sampling ports that corresponded to 330, 470, and 540 injector ports for the three runs. The oxidative intermediate tert-butyl alcohol (tBA) was below its regulatory effluent limit of 12 g/L in two of the three trials. To control tBA, more injection ports were required.

As shown above, additional injection ports increased the bromate concentration above its regulatory limit. Therefore, the experimental HiPOx system was not fully successful with this atypical water at the chosen oxidant doses.

A model calculation is presented. The calculation uses many simplifying assumptions to show that this HiPOx system might have been fully successful at this location under the chosen oxidant doses if the influent bromide concentration had been 0.56 mg/L or less. Because a bromide concentration of 0.56 mg/L is still extremely high for a drinking water source, the HiPOx system appears to hold promise for destroying MTBE and its oxidative by-product tBA while controlling bromate formation, even in waters that have high bromide concentrations.

Before application to other sites, pilot testing will be needed due to the uncertainty in performance resulting from source water quality differences.

Contact

Thomas Speth

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