Abstract:
This research studied the separation of zinc ions from industrial wastewater of zinc phosphate process via a hollow fiber supported liquid membrane.The studied parameters were obtained the type of extractant, the pH of feed solution, the concentration of extraction and stripping solution, the flow rate of feed and stripping solution, effect of diluent that affecting to efficiency of extraction and stripping, lifetime of liquid membrane, initial feed concentration and effect of temperature that affecting to efficiency of extraction and stripping. The result was found D2EHPA in toluene is the most suitable. The optimum condition was achieved at 91% of the extraction and 56% of the stripping under an acceptable lifetime at 210 minutes. The best condition were obtained at 2.5 of a pH in feed solution, 8.3%(v/v) of D2EHPA in toluene, 0.125 molar of a sulfuric acid concentration as the stripping solution and 100 ml/min of volumetric flow rate of feed and stripping solution.Moreover, The diluent have effect to rate of mass transfer as significant that affecting to distribution ratio (D), permeability coefficient (P), mass transfer coefficient of zinc ions in the feed phase (kf) and mass transfer coefficient of zinc ions in the membrane phase (km) which all values are relation with polarity of a diluent and all diluents were studied that found the mass transfer rate of the diffusion of the complex ions of zinc and D2EHPA across the liquid membrane is limiting step. The results of feed solution that can refer to effluent of wastewater from industrial after treated by hollow fiber supported liquid membrane was found the concentration of zinc ions is lower than limited by regulation of Thailandand also the stripping solution can applied to the raw material of electroplating process.