Modeling of sonochemical decomposition of CCl₄ in aqueous solutions

Abstract

In the context of removal of organic pollutants from wastewater, sonolysis of CCl₄ dissolved in water has been widely investigated. These investigations are either completely experimental or correlate data empirically. In this work, a quantitative model is developed to predict the rate of sonolysis of aqueous CCl₄. The model considers the isothermal growth and partially adiabatic collapse of cavitation bubbles containing gas and vapor leading to conditions of high temperatures and pressures in them, attainment of thermodynamic equilibrium at the end of col lapse, release of bubble contents into the liquid pool, and reactions in the well-mixed pool. The model successfully predicts the extent of degradation of dissolved CCl₄, and the influence of various parameters such as initial concentration of CCl₄, temperature, and nature of gas atmosphere above the liquid. In particular, it predicts the results of Hua and Hoffmann (Environ. Sci. Technol. 1996, 30, 864-871), who found that degradation is first order with CCl₄ and that Argon as well as Ar-O₃ atmospheres give the same results. The framework of the model is capable of quantitatively describing the degradation of many dissolved organics by considering all the involved species.