Evaluation of Advanced Oxidation Processes for the Treatment of Methyl Tert-Butyl Ether Drinking Water Treatment in Small Systems

There are approximately 50,000 small community systems and 140,000 non-community systems serving over 25 million transient and non-transient populations of 3,300 people or less. Several of these small systems are having difficulty complying with the ever increasing number of regulations and regulated contaminants and it is estimated that small systems contribute 74 % of the Safe Drinking Water Act (SDWA) and its Amendments (SDWAA) violations annually. Nearly 90% of these are for Maximum Contaminant Level (MCL) violations. EPA conducts in-house technology development and evaluation to support the small communities. As part of this research effort, EPA has been evaluating Advanced Oxidation Processes (AOPs) for the treatment of Methyl tert-Butyl Ether (MTBE) contamination in Drinking Water. MTBE is a gasoline additive that has contaminated drinking water through spills. AOPs utilizing strong oxidants (such as hydroxyl radicals) provide a promising treatment option for the destruction of MTBE for small drinking water treatment systems through chemical transformation without transference to another media (such as an absorbent or to air). A pilot-scale study was conducted at the U.S.EPA Test & Evaluation (T&E) facility in Cincinnati, Ohio to evaluate the ability of three AOPs; hydrogen peroxide/ozone (H₂O₂/O₃), ultraviolet irradiation/ozone (UV/O₃) and ultraviolet irradiation/ozone/hydrogen peroxide (UV/O₃/H₂O₂) to destroy MTBE in drinking water on a pilot scale. The study compared low-pressure (LP) and medium-pressure (MP) UV lamps for their effectiveness in hydroxyl radical generation.