Removal of alizarin red from aqueous solution by ethyl acetate green nanoemulsions

Abstract

The objective of the present study was to develop ethyl acetate (EA) green nanoemulsions for removal of alizarin red (AR) from water. Developed formulations were characterized in terms of thermodynamic stability, self-nanoemulsification efficiency, droplet size, polydispersity, viscosity, refractive index and per cent transmittance. Adsorption studies were performed by mixing small amounts of green nanoemulsions (1 ml) with relatively large amounts of AR solution (10 ml). It was observed that the droplet size, viscosity and % AR removal efficiency were influenced significantly by EA concentration of green nanoemulsions. However, contact time had negligible influence on % AR removal. Based on lowest droplet size (21.3 nm), lowest viscosity (19.3 Pa.s) and highest % AR removal efficiency (72.5%), green nanoemulsion E1 containing 4.0% w/w of EA, 16.0% w/w of Triton-X100, 8.0% w/w of ethylene glycol and 72% w/w of water was optimized as the best green nanoemulsion composition for removal of AR from its bulk aqueous solution.