Use of vegetable oil in supported liquid membrane for the transport of Rhodamine B

The transport of Rhodamine B (RB) from aqueous feed solution containing sodium hydroxide through a flat supported liquid membrane (SLM) sheet containing vegetable oil as a carrier to an aqueous strip phase was investigated. The transport rate of Rhodamine B was found to increase with sodium hydroxide concentration in the feed phase. The influence of pH on the feed (source) phase, the effects of sulphuric acid concentration in the strip (receiving) phase, stirring speed, initial dye (RB) concentration and temperature were studied. Transport kinetics and stability of the membrane were also studied. Polytetrafluoroethylene (PTFE) with 1.0 µm pore size used as the membrane was found to be more permeable than that with 0.5 µm pore size. The feed solution at pH 11 ± 0.1 has the highest permeability. The initial feed solution concentration of 1.06 × 10− 4 mol/L was completely extracted and stripped into 0.3 mol/L sulphuric acid solution in 5 h. Raising of pH in the feed solution from 7 to 13 ± 0.1 leads to an increase in dye permeation from 9.81 × 10− 5 to 6.18 × 10− 4 cm/s. It was observed that dye flux across the membrane tends to increase with stirring speed.