Nonporous homogeneous dense membranes were prepared from the blends of sodium alginate (Na-Alg) with guar gum-grafted polyacrylamide (GG-g-PAAm) in the ratios of 3:1 and 1:1 and these were tested for the pervaporation separation of water-acetic acid mixtures at 30 degreesC. Blend compatibility was studied in solution by measuring the viscosity and the speed of sound. Membranes were crosslinked by glutaraldehyde, The GG-g-PAAm polymer and the crosslinked blend membranes were characterized by Fourier transform infrared spectra. High separation selectivity was exhibited by the pure Na-Alg membrane for water-acetic acid (HAc) mixtures containing 20 mass % of water. The permeation flux increased with increasing mass percent of water in the feed as well as with an increase in the amount of GG-g-PAAm in the blend, but separation selectivity decreased. Sorption selectivity was higher for the Na-Alg membrane than for the blend membranes, but it decreased with increasing mass percent of GG-g-PAAm in the blends. Diffusion selectivity values vary systematically with the blend composition, but not with the amount of water in the feed. Diffusion coefficients of the water-HAc mixtures were calculated from Fick's equation using sorption data and compared with those calculated from flux values obtained in pervaporation experiments. The Arrhenius activation parameters were calculated for the 20 mass % of water in the feed using flux and diffusion data obtained at 30, 40, and 50 degreesC. The diffusion and pervaporation results are explained in terms of solution-diffusion concepts.