Organic-fouling inevitable, control achievable: Mitigation strategies in electro-driven membrane systems

Organic fouling is one of the primary factors limiting the long-term stability of electro-driven membrane systems (EDMS). This review synthesizes evidence on over 60 identified organic-foulants, including organic acids, surfactants, pharmaceuticals, proteins, polysaccharides, and polymers, organizing and evaluating foulants based on molecular size, charge, and cleanability. Systematic comparison reveals that low-molecular-weight and aromatic species penetrate deeply and cause irreversible fouling, while macromolecular and colloidal organics form removable surface layers. We assess trade-offs between aromatic and aliphatic backbones, the role of side-chain functionalities in tuning interfacial affinity, and diverse surface-engineering strategies that enhance resistance to organic fouling. Beyond phenomenological observations, the review highlights multilevel mitigation strategies encompassing pretreatment, electrodialysis reversal, high-frequency pulsing, surface modification, and intelligent cleaning design. In conclusion, while organic fouling remains an inherent challenge, this review confirms that its effects are controllable through integrated material and process strategies, ultimately upholding the central tenet of "Organic-Fouling Inevitable, Control Achievable" and laying the groundwork for next-generation anti-organic-fouling EDMS.