Liquid–liquid extraction of methylene blue dye from aqueous solutions using sodium dodecylbenzenesulfonate as an extractant

The extraction of methylene blue dye from aqueous solutions has been investigated using sodium dodecylbenzenesulfonate as an extractant. The various diluents used were benzene, toluene, xylene and dichloroethane. Dichloroethane was found to be the most effective diluent for the extraction of the dye. The investigated parameters, governing the extraction of the dye, were equilibrium time, pH of the dye solution, extractant concentration, dye concentration, temperature and aqueous to organic phase ratio. The dye was totally extracted at the optimum conditions. The dye loaded in the organic phase was stripped using various types of acids as stripping agent; complete recovery of the dye was achieved using 0.5 M thiourea in 1 M HCl.