Dialysis is a membrane based separation process in which the concentration gradientacross the membrane is the driving force resulting in a flow of material from one sideof the membrane to the other. In this study membranes (Accurel, Celgard, GVHP,PM30 and PTHK) with different pore sizes were employed to characterise the transportof lithium ion in various (0.01, 0.1, 0.5, 1 and 2.5 w/v percent) initial feedconcentrations via the dialysis process. This may be considered as a basis forwastewater treatment containing metal ions. The results show that low initial feedconcentration causes less passage of ions through the membrane due to low drivingforce i.e. concentration gradient across the membrane. The investigation of the effect ofmembrane pore size on ion transport revealed that large pore size membranes provideless penetration of the metal ions through the membrane. These reproducible results,which are not expected, have been explained by the transport mechanism. Two types ofmechanisms (extensive versus intensive) have been suggested for metal ion transportthrough different membranes. If the mechanism of ion transport is intensive, more ionspass through the membrane. Extensive mechanism results in lower ion transportthrough the membrane.
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