DEGRADATION OF TRIETHYLENE GLYCOL DIMETHYL ETHER BY OZONATION COMBINED WITH UV IRRADIATION OR HYDROGEN-PEROXIDE ADDITION

Ozonation of pure aqueous solutions of the polar aliphatic refractory triethylene glycol dimethyl ether (TEGDME) which is a typical represen tative of organic solutes of oil reclaiming wastewaters does not lead to effective mineralization unless high ozone doses are applied. Small doses of UV irradiation do not markedly increase TEGDME mineralizatio n by ozonation, but transformation to more oxidized products (mainly c arboxylic acids containing methoxy and/or ethoxy groups) which are bio degradable to a higher degree than TEGDME. Addition of high concentrat ions of hydrogen peroxide during ozonation results in efficient increa se of TEGDME mineralization, however. The presence of humic acids - wh ich is a consequence of biological treatment of wastewaters containing biodegradable organic constituents - has a beneficial effect on trans formation of TEGDME during ozonation or ozone/UV treatment because hyd rogen peroxide is formed during ozonation of humic acid C-C double bon ds. (C) 1997 IAWQ. Published by Elsevier Science Ltd.