Commercially available methylene blue dye was used for the
preparation of synthetic dye solution. The dye was obtained
from El-Nasr Company, Alexandria, Egypt, and its molecular
structure is shown in Fig. 1. Sodium dodecylbenzenesulfonate
(MW= 348.5) was used as an ionic surfactant. The solvent
used for the removal of dye from water was dichloroethane.
UV–visible spectrophotometer (Labomed, USA) with the calibration
method at maximum wavelength of 640 nm was used
to measure the absorbance of the dye. pH of an aqueous solution
was measured by a pH meter and was adjusted by sodium
hydroxide and nitric acid solutions. The dye solution was prepared
in distilled water. Hydrochloric acid mixed with thiourea
was used as stripping agent. All chemicals used in this study
were of AR grade.