Degradation of reactive yellow K-RN by electricity/potassium permanganate/peroxymonosulfate system and its mechanism
The removal of organic dyes in printing and dyeing wastewater has been a difficult problem in water treatment technology for a long time.Electricity/potassium permanganate/peroxymonosulfate(EC/PM/PMS)system can efficiently degrade refractory organic dyes,such as reactive yellow K-RN.However,the degradation mechanism,especially the activation mechanism of Mn in relation to PMS,remains unclear.Therefore,this paper studied the types and production pathways of active substances in EC/PM/PMS system,and determined the action mechanism of Mn and the activation process of PMS during printing and dyeing wastewater treatment.Results showed that EC/PM/PMS system is a composite system including free radical oxidation and non-free radical oxidation.During this process,PMS activates Mn(Ⅴ),Mn(Ⅵ)and amorphous manganese dioxide,resulting in the reduction of PM.In addition,reactive oxygen radical oxidation is the main degradation path accounting for 95.3%,while electrode direct oxidation and non-free radical oxidation account for 2.1%and 2.6%,respectively.