Sustainable and Rapid Water Purification at the Confined Hydrogel Interface

Abstract Emerging organic contaminants in water matrices have challenged ecosystems and human health safety. Persulfate‐based advanced oxidation processes (PS‐AOPs) have attracted much attention as they address potential water purification challenges. However, overcoming the mass transfer constraint and the catalyst's inherent site agglomeration in the heterogeneous system remains urgent. Herein, the abundant metal‐anchored loading (≈6–8 g m⁻²) of alginate hydrogel membranes coupled with cross‐flow mode as an efficient strategy for water purification applications is proposed. The organic flux of the confined hydrogel interfaces sharply enlarges with the reduction of the thickness of the boundary layer via the pressure field. The normalized property of the system displays a remarkable organic (sulfonamides) elimination rate of 4.87 × 10⁴ mg min⁻¹ mol⁻¹. Furthermore, due to the fast reaction time (<1 min), cross‐flow mode only reaches a meager energy cost (≈2.21 Wh m⁻³) under the pressure drive field. It is anticipated that this finding provides insight into the novel design with ultrafast organic removal performance and low techno‐economic cost (i.e., energy operation cost, material, and reagent cost) for the field of water purification under various PS‐AOPs challenging scenarios.