Tailoring ultrafiltration membranes with chemically modified human hair waste for improved permeability and antifouling performance

Human hair, a pervasive waste product, has the potential to pose environmental challenges due to its widespread accumulation. Therefore, exploring of alternatives that repurpose this waste into a valuable raw material aligns with the principles of the circular economy. This study intro- duces a novel protocol for crafting biohybrid ultrafiltration (UF) membranes with tailored charges, enhanced hydrophilicity, and notable attributes of high flux, rejection rate, and resis- tance to fouling. These membranes have been engineered by combining sulfonated poly(ethersul- fone) (SPES) with chemically modified human hair (HH) filler, referred to as HH-SO3-NH2, utiliz- ing the non-solvent induced phase separation (NIPS) approach. The preparation of HH-SO3-NH2 involved converting of oxidized thiol groups within human hair to sulfonic acid. Subsequently, 1 and 3 wt percent of HH-SO3-NH2 were integrated into the SPES matrix to formulate the biohybrid membranes. After incorporating HH-SO3-NH2, the biohybrid membranes changed in mechanical properties, porosity, and surface morphology, resulting in increased hydrophilicity. The pure wa- ter flux exhibited a systematic rise with higher HH-SO3-NH2 content-specifically, the hybrid membrane with 3 wt% HH-SO3-NH2 achieved a water flux of 239 L m−2 h−1 at 1 bar feed pres- sure, representing a 1.5-fold increase compared to the bare membrane's 175 L m−2 h−1 flux. The anti-fouling performance was assessed using humic acid (HA) and the hybrid membranes demon- strated removal efficiency of HA exceeding 99% without compromising rejection rates.