摘要
This study concentrated on degradation of fenuron (FEN) from aqueous solutions by manganese dioxide (MnO2)-peroxymonosulfate (PMS) system. The performance of commercial (c)MnO2, beta (b)MnO2 and alpha (a)MnO2 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 degrees C to 40.0 +/- 0.5 degrees C. The radical quenching analysis showed that sulfate radical (SO4.-) 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.