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Toseparate a salt mixture (mainly consisting of Na2CO3and Na2SO4) which is formedfrom the 4,4′-diaminostilbene-2,2′-disulfonic acid wastewatertreatment, the solubility data of Na2CO3andNaHCO3in Na2SO4–water solventmixtures were measured using a dynamic method over the 275–335K temperature range. The solute-free mass fraction of Na2SO4in the solvent mixtures extended from 0 to 0.25. Thesolubility of Na2CO3and NaHCO3inNa2SO4–water solvent mixtures decreasedwith addition of Na2SO4. With rising temperature,the solubility of NaHCO3increased while the solubilityof Na2CO3increased at first and then decreasedafter transition points. The experimental data were correlated withthe electrolyte nonrandom two-liquid model. The root-mean-square deviationsof solubility temperature varied from 0.35 to 1.50 K. Based on thesolubility data of this work, a new strategy for separating the Na2CO3and Na2SO4mixture wasproposed theoretically. [ABSTRACT FROM AUTHOR]

Solubilities of nonanedioic acid in binary ethanol + water solvent mixtures have been determined by the dynamic method using a laser monitoring observation technique over a temperature range from (292.35 to 345.52) K and a solvent composition, mole fraction of ethanol of solute-free x20, range from 0.0 to 1.0. The experimental results showed that in pure water the solubility of nonanedioic acid increased slowly with temperature below 342.77 K but increased significantly above 342.77 K. The nonanedioic acid + ethanol + water system was found to exhibit a synergistic effect on solubility. The fusion enthalpy and melting temperature of nonanedioic acid were measured by differential scanning calorimetry. The modified λhequation, the Wilson equation, and the NRTL equation have been applied to correlate a subset of the experimental data. These models can successfully describe the solubility of nonanedioic acid in the binary mixtures with an ethanol mole fraction higher or equal to 0.2811. [ABSTRACT FROM AUTHOR]

The solubilities of sebacic acid in mixed solvents n-propanol + water have been measured by a dynamic method using a laser monitoring observation technique over a temperature range (288 to 351) K. A synergistic effect on solubility was found to occur in sebacic acid + n-propanol + water mixed systems. To detect the synergistic effect, solubilities of sebacic acid in 14.35 %, 36.97 %, 79.81 %, and 90.00 % mole fraction ethanol aqueous solution were determined to supplement our previous report. A weak synergistic effect was found for sebacic acid + ethanol + water mixed systems. The solid−liquid equilibrium (SLE) data have been fitted using the λhequation, the Wilson equation, and the NRTL equation. The comparison between the experimental and the calculated solubilities for the three models is reasonable, and the root-mean-square deviations for each system range from (0.30 to 1.95) K. [ABSTRACT FROM AUTHOR]