Sustainability-Inspired Upcycling of Organophosphorus Pollutants into Phosphatic Fertilizer in a Continuous-Flow Reactor.

With the increasing requirement for phosphorus resources and their shortage in nature, cyclic utilization of organophosphorus pollutants into phosphatic fertilizer might offer a sustainable approach to achieve the recycling of phosphorus. Herein, we first report the selective degradation of organophosphorus pollutants, via the synergistic effect of peroxymonosulfate (PMS) and sodium percarbonate (SPC), into phosphates (o-PO ), which are continually converted into phosphatic fertilizer by struvite precipitation on the continuous-flow reactor. Quenching experiments, electron paramagnetic resonance (EPR) results, electrochemical analysis, and density functional theory (DFT) calculation suggest that the transfer of electrons from SPC to PMS results in the synthesis of catalytically active species (i.e., ·OH, ·O , O, and CO·) for hydroxyethylidene-1,1-diphosphonicacid (HEDP) degradation. For the real glyphosate wastewater, the PMS/SPC system exhibits excellent catalytic activity with 69.20% decrease in chemical oxygen demand (COD) and 37.80% decrease in the total organic carbon (TOC) after 90 min. Indeed, high performance liquid chromatography (HPLC) confirms that glyphosate is completely degraded in 90 min with the formation of 271.93 µmol/L of o-PO , which is further converted into phosphatic fertilizer by the precipitation of struvite with 87.20% yield on continuous-flow reactor. Finally, biotoxicity of glyphosate to zebrafish and wheat seeds are significantly deceased after treatment of PMS/SPC system by zebrafish toxicology assays and germination tests of wheat seeds.