Anti-fouling PVDF membranes incorporating photocatalytic biochar-TiO2 composite for lignin recycle

Abstract

In this study, a photocatalytic biochar-TiO2 (C–Ti) composite was prepared using lignin as carbon precursor, and blended with PVDF polymer to fabricate PVDF/C–Ti MMMs via non-solvent induced phase inversion. The prepared membrane demonstrates both 1.5 times higher initial and recovered fluxes than the similarly prepared PVDF/TiO2 membrane, suggesting the C–Ti composite can help maintain higher photodegradation efficiency and better anti-fouling performance. In addition, the comparison of PVDF/C–Ti membrane against pristine PVDF membrane show that the reversible fouling and photodegradation reversible fouling of BSA increased from 10.1% to 6.4%–35.1% and 26.6%, respectively. And the FRR of PVDF/C–Ti membrane was 62.12%, 1.8 times that of PVDF membrane. The PVDF/C–Ti membrane was also applied for lignin separation, where the rejection to sodium lignin sulfonate was maintained at about 75%, and the flux recovery ratio after UV irradiation reached 90%. The demonstrated the advantages of PVDF/C–Ti membrane in photocatalytic degradation and antifouling performance.