Oxidation of MTBE by ozone and peroxone processes

Initial pilot-scale investigations demonstrated that both ozone as peroxone ) can remove methyl tertiary butyl ether (MTBE) from one and a combination of ozone and hydrogen peroxide (known water sources used by the Metropolita n Water District of Southern California. Under the tested conditions, perox one more effectively removed MTBE than did ozone alone. In pilot tests, per oxone (here, 4 mg/L ozone and 1.3 mg/L hydrogen peroxide) removed an averag e of about 78 percent of the MTBE from water samples taken from the Califor nia State Water project and the Colorado River. However, in peroxone-treate d samples from both water sources at ambient conditions, bromate was produc ed at concentrations above the maximum contaminant level of 10 mu g/L for b romate in drinking water. A lower pH of 6.5 reduced bromate formation by ab out 20 percent in samples from both water sources, but it did not reduce th e bromate concentration below 10 mu g/L (the water sources contained about 0.1 mg/L bromide). Further optimization of the peroxone process may minimiz e bromate formation while providing acceptable MTBE removal and disinfectio n.