Biodegradable Paper-Based Membranes for Water Treatment

A biodegradable nanofiltration membrane has been obtained for the processes of water purification from calcium and magnesium cations. The membrane is obtained on a porous paper substrate with a surface layer of cellulose acetate (CA); ethanol is added as a pore former to the polymer solution. It is found that the surface of the membranes is hydrophilic; the total porosity of the membrane is 51%. According to the results of the SEM study, the membrane consists of a paper substrate (90 mu m), a porous CA layer (8-10 mu m), and a dense CA surface layer (1 mu m). The resulting MCA3 membrane has been used for nanofiltration of tap water, where a high retention capacity for calcium and magnesium ions has been shown (77.2% at a specific productivity of 111 dm3/(m2 h)), which is not inferior to the parameters of a commercial nanofiltration membrane. The possibility of natural decomposition of spent membranes in the soil cover was studied in this work. The obtained composite membranes decompose by more than 60% within 24 days.