Glutaraldehyde and polyvinyl alcohol crosslinked cellulose membranes for efficient methyl orange and Congo red removal

Self-standing and flexible regenerated cellulose membranes were fabricated by using a facile ZnCl2/CaCl2/cellulose dissolution system. The filtration experiments of the membranes were conducted by using methyl orange and Congo red as water contaminations. To improve the selectivity and stability, the crosslinkers of glutaraldehyde and polyvinyl alcohol were introduced to the membrane network. The best performance was observed over glutaraldehyde and polyvinyl alcohol crosslinked cellulose (P-G-RC) membrane with a Congo red rejection rate of 99.9% and a methyl orange rejection rate of 93.5%. The suitable pore radius (0.67 nm), low root-mean-square roughness (2.9 nm) and abundant hydroxyl groups were considered as the primary reasons contributed to the separation behavior. Furthermore, the P-G-RC membrane displayed excellent stability and reusability during the filtration tests.