A full mechanistic and kinetics analysis of carbon tetrachloride (CCl4) sono-conversion: Liquid temperature effect

Abstract

In this study, a model of CCl4 sono-pyrolysis inside an acoustic bubble is used to provide a novel mechanistic and kinetics study of CCl4 conversion. The impact of fluid temperature (10-50 degrees C) on CCl4 conversion and the resulted products is illustrated for various aqueous CCl4 concentrations and acoustic intensities (0.7-1.5 W/cm(2)). With a concentration less than 3 x 10(-3) M, 1 W/cm(2) is sufficient for the complete degradation of CCl4 at 20 degrees C. However, at 10 degrees C, 1.5 W/cm(2) is much than enough to degrade CCl4 completely, regardless of its concentration in solution. The generation of reactive chlorine species (RCS) increased proportionately with the temperature rise when the intensity was 0.7 W/cm(2). In contrast, between 1 and 1.5 W/cm(2), increasing the liquid temperature from 10 degrees to 40 degrees C has a beneficial effect on the sonolytic activity of the cavity. However, this positive impact continues to be observed only for center dot OH radicals when the bulk liquid temperature is greater than 40 degrees C (the yield of RCS, H center dot, HCl, and HOCl is amortized). According to the simulation results, it was concluded that the rapid sonodegradation of nonvolatile pollutants in the presence of CCl4 was mainly due to the RCS and center dot OH radicals generated at the efficient bubble collapse.