Enhanced Peroxydisulfate Activation by Co-Doping of Nitrogen, Chlorine, and Iron: Preparation, Synergistic Effects, and Application

The continuous increase in solid waste poses a significant environmental challenge. Pyrolysis represents a crucial technology for the valorization of solid waste. As the primary product, biochar has found applications in numerous fields and garnered significant scientific interest. This study investigated the potential of NH4Cl and FeCl3 for modifying biochar. The resultant modified biochar achieved over 70% sulfamethoxazole (SMX) degradation within 30 min. The incorporation of NH4Cl and FeCl3 facilitated the formation of pyridinic nitrogen (N), graphitic nitrogen (N), and Fe(II) 1/2p, while the concomitant increase in persistent free radicals facilitated enhanced electron transfer rates. Notably, NH4Cl/FeCl3-modified biochar demonstrated superior efficacy compared with alternative activation techniques for real wastewater treatment. This study presents a novel material for persulfate (PDS)-based advanced oxidation processes, while also offering a cost-effective strategy for solid waste disposal.