Beyond Hydrophilicity: Mapping Multidimensional Interplay Governing Membrane Fouling in Wastewater Reclamation

Membrane fouling remains a major challenge in water treatment, yet the lack of standardized evaluation methods has led to inconsistent conclusions regarding the key membrane properties governing antifouling performance. To address this gap, we systematically fabricated 97 microfiltration/ultrafiltration membranes with precisely controlled hydrophilicity (water contact angle 18°–106°), pore size (0.03–4.80 μm), surface roughness ( R a = 20–276 nm, 10 × 10 μm 2 ), and zeta potential (−34 to −2 mV) via blending, grafting, and nanocasting. Using a stage-resolved membrane fouling assessment framework, we quantified the dominant factors influencing initial fouling rate, long-term permeability stability, and cleaning efficiency. Key findings reveal that water permeability, which is directly correlated with pore size ( ρ = 0.526) and roughness (ρ = 0.386), significantly accelerates initial fouling (ρ = 1.150). While hydrophilicity mitigates initial-stage fouling, it may concurrently reduce cleaning efficiency. This is because hydrophilic loading could endow the membrane surface with high surface energy and elevate the absolute zeta potential value, and this synergy exacerbates irreversible foulant adsorption via strengthened interfacial interactions. Surface roughness indirectly impaired cleaning by enhancing permeability, whereas larger pores improved cleaning efficiency despite lowering normalized permeability (ρ = –1.077). This study establishes a multivariate optimization framework that transcends the conventional hydrophilicity-centric design paradigm, clarifying hydrophilicity’s stage-dependent dual effects and the interdependent regulatory roles of membrane properties across distinct fouling stages, offering targeted guidance for the rational design of next-generation antifouling membranes.