Equilibrium studies on the extraction of Cr(VI) in various solvent phases have been performed. The organic solvent phase consists of Aliquat-336 (a cationic carrier) dissolved in kerosene/Shellsol TK (as an organic solvent) and hexanol (as a phase modifier). The values of the distribution coefficient for the extraction have been obtained by varying the following experimental conditions: feed solution pH (range 9-12); initial feed phase concentration (25 ppm ≤ Cr(VI) ≤ 1000 ppm); and composition of the organic phase (2 vol % ≤ Aliquat-336 ≤ 50 vol %). Re-extraction of Cr (VI) from the solvent phase was examined with an aqueous solution of HCl or NaCl by varying its pH (range 1-12) and concentration (0.5-2 mol·L-1). The values of the partition coefficient for this process are also presented. The extraction and re-extraction reaction coefficients were calculated by combining the experimental data and the kinetic expressions for the interfacial reactions. These values are presented and compared with the literature values.
ASJC Scopus subject areas
- Chemical Engineering(all)