Fe3o4 Magnetic Nanoparticles As A Catalyst Of Oxone For The Removal Of A Typical Amino Acid

Dissolved organic nitrogen (DON) has been a subject of studies on drinking water treatment because of its potential to form nitrogenous disinfection by-products. Histidine was used in a study on the efficiency and mechanism of amino acid removal in a Fe3O4/oxone (PMS) system. The effects of Fe3O4 dosage, PMS dosage, and pH on the removal efficiency were investigated. The results show that the rates of DON and histidine removal within 1 h in the Fe3O4/PMS system are 45% and 57%, respectively. The optimum pH for histidine degradation is 7, and the optimal dosages of Fe3O4 and PMS are 0.1 g/L and 1.5 mmol/L, respectively. SO4-center dot and (OH)-O-center dot induced by the transformation of Fe2+-Fe3+ on the catalyst surface apparently led to the degradation, indicated by electron spin resonance results, with SO4-center dot playing a more important role. The products of the reaction reveal that the part of the histidine was oxidized to NH4+-N within 60 min and no N-2 and NO3-formed during the process. Analytical results of high-performance liquid chromatography-mass spectrometry suggest that histidine degradation follows the two separate pathways involving SO4-center dot and (OH)-O-center dot, but both gradually convert -NH2 into NH4+-N.