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 introduces a novel protocol for crafting biohybrid ultrafiltration (UF) membranes with tailored charges, enhanced hydrophilicity, and notable attributes of high flux, rejection rate, and resistance to fouling. These membranes have been engineered by combining sulfonated poly(ethersulfone) (SPES) with chemically modified human hair (HH) filler, referred to as HH-SO₃-NH₂, utilizing 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 water 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 pressure, 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 demonstrated removal efficiency of HA exceeding 99% without compromising rejection rates.