TGA/DTA data .Membranes were repared from sulfonated polymerand performance characteristics in terms of permeate flux and solute separation are reported .The effects of the casting solution composition on performance of both PES & SPES membranes, effect of feed con-centration and separation of different inorganic salts are also included.Separation of multivalent cation (Ca2+) was studied in presence of PAA of different concentration and as a function of pH.