OXIDATION OF METHYL TERTIARY-BUTYL ETHER (MTBE) BY OZONE AND PEROXONE AND IDENTIFICATION OF BY-PRODUCTS

摘要

A study was conducted to investigate the impact and significance of oxidation of ozone andPEROXONE (ozone combined with hydrogen peroxide) for methyl tertiary-butyl ether (MTBE)removal from the City of Santa Monica’s groundwater. Experiments conducted in a semi-batchreactor demonstrate that PEROXONE (a PEROXONE ratio of 1.0 and applied ozone doses up to10 mg/L) was consistently effective in oxidizing MTBE than was ozone alone. However,appliedozone doses greater than 10 mg/L are necessary for both spiked MTBE concentrations at approximately200 and 2,000 μg/L to achieve MTBE levels below the California drinking water secondarystandard of 5 μg/L. Both ozone and PEROXONE can degrade MTBE into biodegradableproducts such as t-butyl formate,t-butyl alcohol,acetone,and aldehydes (including formaldehyde,acetaldehyde,heptaldehyde,glyoxal,and methyl glyoxal). In addition,PEROXONE canoxidize MTBE more rapidly than ozone alone. When PEROXONE was used,the formationof bromate ranged from “not detected” (N.D.) to 13 μg/L (waters containing approximately0.3 mg/L bromide) exceeded the maximum contaminant level (MCL) of 10 μg/L. It appearedthat bromate formation can be effectively controlled with hydrogen peroxide-to-ozone ratiosgreater than 1.0. Therefore,PEROXONE may be a suitable alternative for the removal of MTBEfrom contaminated groundwater in the future.