Acetaminophen removal from aqueous solutions through peroxymonosulfate activation by CoFe2O4/mpg-C3N4 nanocomposite: Insight into the performance and degradation kinetics

In this study, a mesoporous composite (CoFe2O4/mpg-C3N4, CF/MCN) was synthesized by a simple method. The characteristics of the prepared sample were determined by different methods including XRD, FESEM, EDX-map, FTIR, BET, and pH(zpc). Characterization results showed that CF/MCN was well synthesized with small size and good dispersion of CF nanoparticles. Catalytic activity of CF/MCN was evaluated by peroxymonosulfate (PMS) activation to degrade acetaminophen (APAP) through the generation of free radicals. The effect of key factors of CF/MCN/PMS process on APAP degradation was assessed. CF/MCN/PMS degraded more than 92% of APAP under the conditions of pH = 7.0, PMS = 1.5 mM, 40 mg/L CF/MCN and 25 min reaction time. Pseudo-first order kinetic model was fitted for APAP removal and the rate constant obtained was 0.1023 min(-1). Sulfate radical (SO4 center dot-) was the main contributor in APAP degradation. Carbonate and chloride ions had a strong inhibitory effect on APAP degradation whereas other anions (nitrate and sulfate ions) affected slightly APAP degradation. CF/MCN was a reusable catalyst for four times without any significant reduction in catalytic activity. Leaching experiments demonstrated a negligible concentration of Co and Fe indicating that homogeneous activation did not contribute in the generation of free radicals. The CF/MCN exhibited high catalytic activity for mineralization of APAP compared to other conventional metal oxides. This method can be used as an alternative advanced oxidation process for efficient degradation of emerging pollutants in water. (C) 2020 Elsevier B.V. All rights reserved.