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Vapor−liquid−liquid equilibrium data for the binary systems 2-methyl-1,3-dioxolane + water and 2,4-dimethyl-1,3-dioxolane + water were collected by using a modified Othmer still vessel at 1 atm of pressure. The UNIQUAC equation of state was fitted to the experimental T−x−x−y data to generate the coefficients of the binary interaction parameters for each system. Vapor pressures for pure 2,4-dimethyl-1,3-dioxolane and 2-methyl-1,3-dioxolane were also measured and used to calculate the constants in Antoine's equation and pure component parameters for each dioxolane. The enthalpy of vaporization calculated from vapor pressure data via the Clausius−Clapeyron equation was in good agreement with the literature value.

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To address problems associated with treatment of an aqueous waste stream from a reactive dye house, a model dye, turquoise blue CI25, was studied. A hybrid technology, membrane separation followed by sonication and wet oxidation, has been demonstrated to treat the wastewater for reuse and discharge. Experiments were first performed with the reactive dye solution in water. A nanofiltration membrane (MPT 30) was found to be suitable to concentrate the dye. The concentrate was then treated with a wet oxidation process. Kinetics studies were performed with and without catalyst, in the temperature range of 170-215°C. The color destruction achieved was >99%. After process parameters were fixed, studies were conducted with the actual dye waste stream. The actual waste stream was found to be refractory for wet oxidation under the above conditions. Sonication of the concentrate obtained after membrane filtration, in the presence of CuSO 4 , made the waste stream amenable to wet oxidation. Sonication followed by wet oxidation was found to be more effective at near neutral conditions as compared to basic conditions.