Effect of hydrophobic and hydrophilic nanoparticles loaded in D2EHPA/M2EHPA - PTFE supported liquid membrane for simultaneous cationic dyes pertraction.

Cationic dyes mixture pertraction experiments of Rhodamine B (RhB) and Methylene Blue (MB) using a flat sheet supported liquid membrane (SLM) were performed. Mono-(2-etylhexyl) ester of phosphoric acid (M2EHPA) and bis-(2-etylhexyl) ester of phosphoric acid (D2EHPA) mixture was used as carrier and Sesame oil to dilute the carrier due to its very high viscosity. Acetic acid (AA) was also used as stripper phase. Influences of hydrophobic and hydrophilic nanoparticles were loaded in a carrier at different loadings (from 0 to 6 mg mL) on dyes pertraction at constant operating conditions were investigated. It was found that hydrophilic nanoparticles, including ZnO and TiO decrease dyes pertraction, while hydrophobic nanoparticles, including ZIF-8 and FeO favorably increase this parameter. ZIF-8 was found as the most effective nanoparticles on increasing dyes pertraction and the optimum loading was 2 mg mL. Also, the important process parameters that influence on the dyes mixture pertraction efficiency such as feed concentration, carrier concentration, feed pH and strip concentration were studied. In order to investigate the effects of operating parameters, all experiments were performed at a constant 2 mg mL ZIF-8 loading. Optimum pertraction efficiency of RhB and MB were 90.6 and 79.4%, respectively. They were obtained after 10 h pertraction at optimum experimental conditions with feed concentration of 100 mg L, carrier concentration of 35% (vol), strip concentration of 0.5 mol L, and feed pH of 6. Effect of time on pertraction efficiencies at the optimum conditions were also studied.