SURVEY ON DEGRADATION RATES OF TRICHLOROETHYLENE IN AQUEOUS SOLUTIONS BY ULTRASOUND

Sonochemical degradation of different compounds such as chlorinated aliphatic hydrocarbons is one of the recent advanced oxidation processes and it may be effective for removing low concentration organic pollutants from aqueous streams. Trichloroethylene (TCE) is one of these compounds that is mainly used as a degreaser. Important studies about TCE sonolysis have been focused at millimolar levels and natural pH, but in this study the ultrasonic degradation of TCE at different micromolar initial concentrations (30, 300 and 3000 µg/L) and 4 different initial pH with a 35 kHz frequency was investigated. Furthermore, the degradation of TCE by ultrasound with different concentrations of hydrogen peroxide at pH= 7 was also performed. Gas chromatography with FID detector was used for analyses of TCE. Results showed that the degradation of TCE increased with decrease in the initial concentration of TCE from 3000 to 30 µg/L at all initial pH. Initial pH of solution and different concentrations of H^sub 2^O^sub 2^ did not affect significantly the TCE destruction. [PUBLICATION ABSTRACT]