The analysis of efficiency of activated peroxymonosulfate for fenuron degradation in water

This study concentrated on degradation of fenuron (FEN) from aqueous solutions by manganese dioxide (MnO 2 )-peroxymonosulfate (PMS) system. The performance of commercial (c)MnO 2 , beta (b)MnO 2 and alpha (a)MnO 2 in combination with PMS was investigated. The degradation efficiency of applied systems followed the order: aMnO 2 -PMS system > bMnO 2 -PMS system > cMnO 2 -PMS system. The 38.0% degradation of 20.0 mg/L was achieved by aMnO 2 -PMS system after 180 min at initial pH 7.0 using 0.6 g/L aMnO 2 and 2.0 mmol/L PMS. The degradation by aMnO 2 -PMS system was affected by initial PMS and FEN concentrations, aMnO 2 dosage, pH and temperature. The degradation decreased with increasing pH from 3.0 to 11.0 and increased with increasing temperature from 25.0 ± 0 . 5 ∘ $\pm 0.5^{\mathrm{\circ }}$ C to 40.0 ± 0 . 5 ∘ $\pm 0.5^{\mathrm{\circ }}$ C. The radical quenching analysis showed that sulfate radical (SO 4 ⋅− ${}_4^{\mathrm{\cdot -}}$ ) was primarily responsible for degradation. The comparison of degradation efficiency of aMnO 2 -PMS system with degradation efficiencies of pyrite (PyR)-PMS system as well as zero-valent iron (ZVI)-PMS system revealed that activated PMS is not favorable for efficient degradation of fenuron from aqueous solutions.