EXTRACTION OF TEXTILE DYES USING TWO-PHASE AQUEOUS SYSTEMS COMPOSED OF 2-PROPANOL AND SULFATE SALTS

Aqueous Two Phase Systems (ATPS) composed of 2-propanol + inorganic salt (Na2SO4/MgSO4) + water, at different temperatures T = (20, 30, 40 and 50) °C were applied in the partition studies of the textile dyes Yellow, Blue Royal and Red Dianix CC. The thermodynamic parameters of the free transfer energy (∆Gtr), enthalpy (∆Htr) and entropy (∆Str), respectively, were determined for dye partitioning, using the Van’t Hoff equation. The values of the partition coefficients of textile dyes Yellow, Royal Blue and Red Dianix CC, ranged from 14.21 to 1610.00, 15.15 to 994.00 and 17.32 to 311.75, respectively; and with dye extraction yields ranging from 93.17 to 99.93; 94.53 to 99.89 and 97.19 to 99.64, respectively. Based on the ∆Gtr results, it was verified that the dyes partition process was thermodynamically spontaneous, in all evaluated systems. For the 2-propanol + sodium sulfate ATPS, there was a prevalence of the enthalpic contribution over the entropic contribution (∆Htr > ∆Str), while for the 2-propanol + magnesium sulfate systems, a greater predominance of the entropic contribution was observed (∆Htr < ∆Str). The recovery yields (Y) values obtained were above 90% for all systems.