To promote the development of crystallization
technology for recovering
salt from high salinity wastewater, the effect of organic impurity
on crystallization of sodium sulfate was investigated by using phenol
as a representative organic impurity. The effect of phenol on crystallization
thermodynamics of sodium sulfate was evaluated by measuring solubility
data of sodium sulfate in water in the presence of phenol. It was
found that the existence of phenol could suppress the solubility of
sodium sulfate in water. The effect of organic impurity on crystal
nucleation was performed by measuring the metastable zone width (MSZW)
and induction time of sodium sulfate. Two models (self-consistent
Nývlt-like equation and Classical 3D nucleation theory) were
used to analyze the experimental data. It was found that Classical
3D nucleation theory (3D CNT) can better explain the effect of phenol
on nucleation. From both MSZW data and induction time data, it was
found that the existence of phenol will apparently increase the interfacial
energy γ, which will result in higher nucleation Gibbs energy
barrier and thus lower nucleation rate. Furthermore, the existence
of phenol will increase the critical nucleus radius r* and the critical Gibbs energy ΔG*, which
means that the formation of the nuclei will be more difficult in the
presence of phenol. According to the above analysis, the possible
mechanism of influence of organic impurity on crystallization of sodium
sulfate was proposed.
The solubility of hydroxyacetic acid in five pure organic solvents and two binary solvent mixtures were experimentally measured from 273.15 K to 313.15 K at atmospheric pressure (p=0.1 MPa) by using a dynamic method. The order of solubility in pure organic solvents is ethanol > isopropanol > n-butanol > acetonitrile > ethyl acetate within the investigated temperature range, except for temperature lower than 278 K where the solubility of HA in ethyl acetate is slightly larger than that in acetonitrile. Furthermore, the solubility data in pure solvents were correlated with the modified Apelblat model, NRTL model, and Wilson model and that in the binary solvents mixtures were fitted to the CNIBS/R-K model and Jouyban-Acree model. Finally, the mixing thermodynamic properties of hydroxyacetic acid in pure and binary solvent systems were calculated and discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.