A low-carbon resource recycling pathway: cellulose nanocrystals (CNCs) membranes derived from waste paper pulp for efficient surface water treatment

In this work, a resource reuse and environmentally friendly production pathway was demonstrated that extracting sustainable materials cellulose nanocrystals (CNCs) from waste paper pulp and fabricate CNCs membranes with hydrophilic surfaces and negative charges. CNCs membranes was formed through chiral structure of CNCs particles combined with polyvinyl alcohol (PVA) and crosslinked with glutaraldehyde, exhibiting high permeation flux (7–25.2 Lm⁻²h⁻¹bar⁻¹), excellent separation efficiency and antifouling performance against natural organic matter (NOM). Three combined cake-filtration models were applied to investigate the fouling behavior of the CNCs membranes. Notably, although the fouling behavior of CNCs membranes was consistent with cake filtration-complete blockage model (CFCBM), the contribution from cake layer precipitation was observed to be greater than that of pore-blocking mechanisms. Moreover, life cycle assessment (LCA) was conducted to evaluate the environmental impact of CNCs membranes, revealing that CNCs membranes exhibited lower environmental impact level and technoeconomic cost. This work introduces a novel approach to the design and application of sustainable materials in membrane fabrication.