Removal of Dyes from Textile Effluent by Using Organic Solvents and Surfactants

Conventionally, dye adsorption and oxidation approaches are usually used to remove dyes from effluent. The new technique is based on liquid-liquid separation via reverse micelles, through which it is possible to recycle dye and solvent. Experiments were performed by mixing a certain amount of dye, aqueous phase, solvent phase and surfactant in a stirrer. Separation of the aqueous phase from the solvent phase containing the dye encapsulated in reverse micelles was carried out by gravity in a burette. The removal of methylene blue and direct red 21 from the aqueous phase was performed by using an anionic (LAS) or a cationic (CTAB) surfactant in benzyl alcohol solvent. Experimental results showed that the removal of dye from the aqueous phase increases by reducing the initial concentration of dye, so that a decrease in initial dye concentration from 3 to 2 mg/L leads to an increase in dye removal efficiency from 59 to 70%. Meanwhile, the presence of anionic surfactant contributed to remove of methylene blue from the effluent up to 73%. Moreover, increasing in retention time also caused an increase in dye removal, so that an increase in retention time from 10 to 20 min leads to an increase in dye removal efficiency from 48 up to 73%. The use of benzyl alcohol in the dye solution caused the dye to be absorbed into the benzyl alcohol and led to a reduction in chemical oxygen demand (COD).