Extraction of chromium (III) from aqueous waste solution in a novel rotor-stator spinning disc reactor

Abstract

In this work, the removal of chromium (III) from aqueous waste solution by solvent extraction with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl (P507) as extractant is investigated in a novel rotor-stator spinning disc reactor. The effect of rotational speed, volumetric flow rate and rotor-stator distance on extraction efficiency and volumetric mass transfer coefficient are studied. Experimental results indicates that the maximum values of extraction efficiency and volumetric mass transfer coefficient are 97.2 % and 0.40 1/s, respectively. The mass transfer performance inside the rotor-stator spinning disc reactor exceeds that of conventional reactors. Moreover, it is found that the extraction efficiency increases with the increase of rotational speed but with the decrease of volumetric flow rate and rotor-stator distance. The Volumetric mass transfer coefficient increases as both the rotational speed and volumetric flow rate increase, but decreases with the increase of rotor-stator distance. Furthermore, an analysis on the relationships between volumetric mass transfer coefficient and various parameters is launched by the grey correlation method. The calculation result shows good coincidence with the experimental data.