Fulvic acid improves the degradation performance of Fe-Mn bimetallic in peroxymonosulfate based advanced oxidation process

The co-existing dissolved oxygen matters exhibited various influences on peroxymonosulfate (PMS) activation and organic contaminants degradation by the Fe/Mn based catalysts. This study has successfully constructed a Fe-Mn bimetallic catalyst (FMB)/PMS system to degrade aniline aerofloat (AAF). It was found the fulvic acid (FA) elevated the degradation efficiency of AAF (100 mg/L) from 73.54 % to 97.81 % within 10 min accompanied by the kinetic constant (k(obs)) increased from 0.237 min(-1) to 0.638 min(-1). The characterization and experimental results demonstrated that the FA-FMB exhibited a superior morphology and structure compared with FMB, contributing to a larger specific surface area (SSA). Meanwhile, FA introduced abundant oxygen vacancies (O-V) into FA-FMB, facilitating the adsorption of PMS and the generation of abundant singlet oxygen (O-1(2)) during the reaction process. While, the O-1(2) played a dominant role in the AAF degradation. Furthermore, the active electron-donating groups in FA endow its enhanced reduction effect on Fe/Mn to promote the activation of PMS by Fe-Mn binary catalyst. This study has provided deep insights into the effect of FA on PMS activation by Fe-Mn bimetallic catalysts.