Making waves: from oxidative coupling to phase separation: a dual-process framework for oxidative polymerization-based water treatment

Oxidative polymerization provides a promising approach for water treatment. It bypasses the oxidation removal pathway, thereby reducing the consumption of oxidants and greenhouse gas emissions. It also enables an integrated process of pollution control and resource utilization. However, its rational design and predictable implementation are impeded by the complex dynamics of polymerization and precipitation. Additional challenges include a limited understanding of the precipitation mechanism and the absence of engineering design guidance based on cross-disciplinary mechanisms. Here, we reframe oxidative polymerization as a dual-process challenge requiring both molecular coupling and phase separation. We identify four key determinants-chain rigidity, hydrophobicity, surface charge, and crosslinking density-that collectively govern precipitability through thermodynamic and kinetic principles. To bridge mechanism with practice, we propose a multidimensional evaluation framework comprising intrinsic propensity, kinetic separability, structural irreversibility, and operational robustness. This holistic metric suite enables rational design, cross-system comparison, and predictable engineering of separation-integrated advanced oxidation processes for contaminant removal.