An anti-fouling,free-standing membrane was synthesized through the polymerization of acrylamide in the presence of sodium alginate using N,N'-methylene-bisacrylamide as the covalent crosslinker and CaCl2 as the ionic crosslinker. The membranes were characterized via field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FT-IR), and Thermal Gravity (TG). Bovine serum albumin (BSA) solution and yeast suspension were used to investigate the anti-fouling performance of the hydrogel filtration membrane. The calcium alginate/polyacrylamide (CA/PAM) filtration membrane exhibited 89.06% and 85.84% water flux recovery for yeast suspension and BSA solution, respectively, without washing the filtration membrane. The hydrogel filtration membrane showed limited adsorption and adhesion for BSA and yeast, and the rejection of BSA and yeast reached 98.53% and 99.64%, respectively. The results of dye rejection studies demonstrated potential applications of this material as a nanofiltration membrane. The free-standing CA/PAM hydrogel filtration membrane exhibits excellent anti-fouling properties and has promising application prospects in the fields of protein separation, microorganism filtration and removal of dyes. (C) 2015 Elsevier B.V. All rights reserved.