Nonionic microemulsion systems applied for removal of ionic dyes mixtures from textile industry wastewaters

A series of physical-chemical parameters (initial dye concentration, pH, salt and sequestrant concentrations) with significant influence on the dye removal efficiency of water/nonionic surfactant/ethyl acetate ternary system has been studied in order to find out the optimal compositions for an efficient extraction of cationic and anionic dyes from aqueous media. The optimum extraction conditions for this system correspond to pH > 5, surfactant concentration around 8% (w/w) and organic phase concentration around 13% (w/w), resulting in extraction efficiencies around 90%. By adding sodium chloride (concentration > 60 g/L) in the ternary system the removal efficiency was improved.