The removal of methyl violet from water by solvent sublation

Methyl violet (M,V. C14H28N3Cl), a cationic dye was removed from an Aqueous solution by solvent sublation of methyl violet-sodium dodecylbenzulfonate (DBS) complex (sublate) into 2-pentanol. A stoichiometric amount of surfactant (surfactant:dye 1:1) was the most effective for the removal, with over 97% MV removed from the aqueous solution in 10 min by solvent sublation. The removal rate was somewhat enhanced by higher airflow rates and almost independent of the volume of the organic solvent floated on the top of the aqueous column. The effects of electrolytes (e.g., KCl), non-hydrophobic organics (e.g., ethanol), and pH of the solution on the process were studied. The comparison of air stripping and solvent extraction with them solvent sublation process was made. The solvent sublation process followed first-order kinetics. A characteristic parameter, apparent activation energy of attachment of the sublate to bubbles, was estimated at a value of 8.19 kJ/mol.