Fenton–coagulation process for simultaneous abatement of micropollutants and dissolved organic carbon in treated wastewater

This study demonstrates the integration of the Fenton reaction into the flocculation process at circumneutral pH (6–7), offering a practical approach for simultaneous micropollutant and organic matter removal in wastewater treatment. Unlike conventional Fenton oxidation, which requires acidic conditions, this approach allows Fe(II) to react with hydrogen peroxide at near-neutral pH, forming Fe(III) flocs that enhance flocculation while also generating reactive species for pollutant degradation. At pH 6, hydroxyl radicals were the dominant oxidants, whereas at pH 7, additional reactive species likely contributed to micropollutant removal. Bisphenol A and benzoic acid were removed by approximately 90% at 1 mM peroxide and 2 mM iron. In addition to micropollutant degradation, the Fenton-coagulation process achieved substantial dissolved organic carbon (DOC) removal, which was not observed with Fenton oxidation alone or ozonation. DOC removal was up to 51% in Suwannee River Natural Organic Matter solutions, whereas only 30% of DOC was removed from municipal wastewater effluent, likely due to differences in organic matter composition. These findings highlight the potential of Fenton-coagulation as an effective and scalable treatment strategy for wastewater reuse, improving both pollutant degradation and organic matter removal under practical conditions.