Methyl tertiary butyl ether (MTBE), the most common oxygenated fuel additive, has been detected in several drinking water supplies in California. MTBE levels as high as 610 g/L in the groundwater of the City of Santa Monica were reported. An action level of 35 g/L for drinking water has been established by the State of California Department of Health Services. In addition to the risk associated with human exposure through drinking water, unpleasant taste and odor should not be detected under this action level.

Removal of MTBE from drinking water can be achieved through several water treatment processes such as air stripping with adsorption of collected material, advanced oxidation, membrane separation, and sorption. Since MTBE is highly water soluble polar compound, high air to water ratios are required in air stripping process. Consequently, the use of the process may not be economical. Membrane separation is considered too expensive for the use in general water treatment applications. Advanced oxidation processes, such as ozone and ozone/peroxide, are very effective in removing MTBE from drinking water; however, bromate is a by-product of these processes. The objective of this research is to determine the cost and effectiveness of sorption process to remove MTBE from drinking water.

Currently, isotherm studies at low to moderate concentrations of MTBE (< 1000 g/L) adsorption, are being conducted. Sorbents used in these studies include granular activated carbons (bituminous, lignite, wood, peat, and coconut), XAD-4 and XAD-8 resins (Amberlite), and XE-572 resin (Ambersorb). Non-traditional sorbents, such as modified clay materials, will also be tested. Competitive studies will be conducted with humic materials and two major oxidation by-products: tertiary butyl alcohol (TBA) and tertiary butyl formate (TBF). The evaluation of sorbents will also consider their use as a polishing method for advanced oxidation system. Based on the results from isotherm studies, effective sorbents will be studied using the laboratory scale rapid small-scale column tests (RSSCT). The RSSCT can simulate the full scale granular activated carbon column performance and the RSSCT results can be used to scale up the columns as well as to evaluate the cost of the process.