Synergistic Catalysis and Adsorption in Cobalt-Embedded Fibers Enable Organophosphorus Degradation and Phosphate Recovery in Persulfate Systems

Considering the persistent ecological risks posed by phosphate byproducts to aquatic systems during organophosphorus pollutant degradation, this study developed an aminated polyacrylonitrile fiber-immobilized nanozero-valent cobalt composite (PANAF-Co), which was utilized to activate peroxymonosulfate (PMS) for degrading phenylphosphonic acid (PPOA) and simultaneously recovering the generated phosphate. Experimental results demonstrated that the PANAF-Co/PMS system achieved 98% PPOA degradation within 60 min across pH 3-9, with 95% efficiency retained under complex matrices (1 mmol·L⁻¹ anions and 20 mg·L⁻¹ humic acid). Furthermore, the modifications of amine groups and metallic cobalt significantly improved phosphate removal efficiency, endowing PANAF-Co with an enhanced adsorption capacity (16.45 mg P·g⁻¹ within 60 min) and robust pH tolerance (4-7). Additionally, PANAF-Co exhibited excellent reusability, retaining 75.3% of its effectiveness after 5 cycles. It also effectively removed organophosphorus from Chaohu Lake water (91.6% removal) and agricultural tailwater (84.7% removal) in practical applications. Mechanistic studies revealed that SO₄·⁻ and ·OH were dominant reactive oxygen species, while phosphate removal was mediated through cobalt-phosphorus coordination and protonated amine synergistic adsorption. In conclusion, this work proposes a novel remediation strategy that simultaneously targets organophosphorus and phosphate, thereby providing a scalable solution for organophosphorus-contaminated wastewater remediation.