Membrane-based extraction of nickel(II) using the mixture acorga M5640 and DP-8R as carrier

An experimental study of Ni(II) transport through a flat-sheet supported liquid membrane using the mixture of Acorga M5640 and DP-8R as carrier was performed at 20 degrees C. The transport system was studied as a function of several variables: stirring speed of the feed (400-2000 min(-1)) and receiving (400-1500 min(-1)) phases, concentration of the strippant (2.5x10(-1) to 1.0 mol L-1 sulfuric acid) in the receiving phase, pH of the feed phase (2 to 5), diluent of the membrane and carrier (2.5% v/v to 20% v/v, each reagent) and metal (1.7x10(-4) to 1.4x10(-3) mol L-1) concentrations in the membrane and feed phases, respectively. Under the present experimental conditions, the transport process is controlled by diffusion of nickel species in the stagnant film of the feed phase, whereas the mass transfer coefficient and the thickness of the aqueous film are estimated as 1.21x10(-3) cm s(-1) and 8.3x10(-3) cm, respectively.