Activation of peroxymonosulfate by CuCo2O4 nano-particles towards long-lasting removal of atrazine

The effect of peroxymonosulfate (PMS) activated by nanocrystalline CuCo2O4 (NPS) on removal of atrazine (ATZ) was studied. First, the main experimental parameters were studied, including CuCo2O4 dose, PMS dose, initial pH value, and co-existing ion. The removal of ATZ (>99%) was attained under the optimal conditions (i.e., 150 mg/L CuCo2O4, 0.2 mM PMS, 5 mg/L ATZ, initial pH value of 6.8, and reaction time of 30 min). However, the removal of ATZ only reached 20.9% in the PMS alone system and there was no significant ATZ removal when adding CuCo2O4 alone into the solution, proving the good performance of the CuCo2O4/PMS system. Furthermore, reusability of CuCo2O4 was tested through five consecutive runs. To confirm which main active radicals were responsible in the system, two radical quenching experiments were carried out and electron paramagnetic resonance (EPR) was tested. In addition, the characterization of fresh and reacted CuCo2O4 NPs was tested by SEM, TEM, EDS, XRD, and XPS. Subsequently, based on the characterization of CuCo2O4 NPs and identification of radicals, equivalent to Cu2+/ equivalent to Cu+ and equivalent to Co3+/ equivalent to Co2+ were considered to be the main catalytic species, while the synergistic effect of Cu and Co played a crucial role. Finally, the degradation pathway of ATZ was proposed.

Automated summary

The study investigated the removal of atrazine using peroxymonosulfate activated by nanocrystalline CuCo2O4, achieving over 99% removal efficiency under optimal conditions. CuCo2O4 played a crucial role in the system, with Cu2+/Cu+ and Co3+/Co2+ identified as the main catalytic species based on characterization and radical analysis. Additionally, the degradation pathway of atrazine was proposed based on the findings.