Donnan dialysis and diffusion dialysis techniques are investigated for deacidification and possible concentration of actinide bearing acidic streams. Cation and anion exchange membranes are used in a two compartment dialysis cell to selectively remove acid from americium solutions. Acid concentrations, as high as 8.0M HNO3 are used and the stability of membranes are ascertained. Possibility of simultaneous deacidification and concentration of acidic americium solutions are indicated by combining simple osmosis with diffusion dialysis. All the experiments are carried out under non stirring conditions at room temperature.