Development of dilutable green nanoemulsions for removal of Eriochrome black T from aqueous solution and optimization by Box-Behnken design

In present study, attempts were made to develop green nanoemulsions for removal of Eriochrome black T (EBT) from its aqueous solution. Box-Behnken design was applied for optimization of nanoemulsion compositions for maximum removal of EBT. Adsorption studies were performed for contact time of 10, 15 and 20 min by mixing small amounts of concentrated green nanoemulsions with relatively large amounts of bulk aqueous solution of EBT. Droplet size, viscosity and % removal were significantly influenced by ethyl acetate & surfactant concentrations and contact time had negligible/little impact on these parameters. Based on lowest droplet size (13.8 nm), lowest viscosity (10.9 cp) and highest % EBT removal efficiency (99.6%), the nanoemulsion N-9 was optimized as the best formulation for removal of EBT. These results indicated that nanoemulsions could be applied successfully for the removal of toxic dyes such as EBT from its aqueous solution via liquid-liquid adsorption. (C) 2014 Elsevier B.V. All rights reserved.