Adsorption-assisted membrane filtration with a cellulose derivative for separation of cationic compounds

This study explores the first-time use of dicarboxymethyl cellulose (DCMC) in an adsorption-assisted membrane filtration (AMF) process for the removal of cationic compounds from aqueous solutions. DCMC and microfiltration commercial membranes were used in an integrated dead-end filtration system, with Cytochrome C (Cyt C) as a model protein. The experiments were performed in a stirred cell with powdered DCMC on the retentate side. The work evaluated the effect of stirring, contact time and membrane material on the removal efficiency. Regenerated cellulose, polyamide and polyethersulfone membranes were tested, showing no significant differences in performance. High retention was achieved without compromising permeability, with fluxes up to 700 L m -2 h −1 . The filtration performance remained consistent after three consecutive regeneration cycles. The adsorption capacity of DCMC was assessed by discontinuous filtration with a PES membrane and 200 mg of DCMC. Following 38 min of filtration, saturation occurred with approximately 1.8 L of a 100 mg L -1 Cyt C solution. The results showed that the AMF system was successfully employed, with the adsorbent (DCMC) playing a crucial role in the removal of Cyt C