(527d) A Zwitterionic Hydrogel-Based Heterogeneous Fenton Catalyst for Water Treatment

Persistent organic pollutants (POPs), including xenoestrogens and PFAS, demand urgent global intervention. Fenton oxidation, catalyzed by iron ions, offers a cost-effective means to degrade POPs. However, numerous challenges like acid dependency, catalyst loss, and toxic waste generation hinder practical application. Efforts to create long-lasting heterogeneous Fenton catalysts, capable of simultaneously eliminating acid requirements, sustaining rapid kinetics, retaining iron efficiently, being compatible with UV light, and being reusable have been unsuccessful. Here, we introduce an innovative heterogeneous zwitterionic hydrogel-based Fenton catalyst, surmounting these challenges in a cost-effective and scalable manner. The hydrogel, hosting individually complexed iron ions in a porous scaffold, exhibits substantial effective surface area and mass transfer-controlled kinetics akin to homogeneous Fenton reactions. Individually complexed ions within the hydrogel can initiate Fenton degradation at neutral pH, eliminating acid additions. Simultaneously, the zwitterionic hydrogel scaffold, chosen for its resistance to Fenton oxidation, forms strong bonds with iron ions, enabling prolonged reuse. Diverging from existing designs, our catalyst proves compatible with UV-Fenton processes and achieves rapid self-regeneration during operation, offering a promising solution for the efficient and scalable degradation of POPs. The study underscores the efficacy of our approach by demonstrating the swift degradation of three significant contaminants - xenoestrogens, pesticides, and PFAS across multiple cycles at trace concentrations.