Degradation characteristics of humic acid over iron oxides/Fe 0 core-shell nanoparticles with UVA/H2O2.
Iron oxides coated on Fe(0) core-shell nanospheres (nIOCI) were synthesized through the reduction of ferrous sulfate aqueous solution by sodium borohydride at ambient atmosphere. The catalyst was highly effective for the degradation of humic acid (HA) in the presence of H(2)O(2) and UVA at neutral pH. Under deoxygenated conditions in the dark, the generation of hydroxyl radicals in aqueous nIOCI dispersion verified its galvanic cell-like performance, which enhanced the interfacial electron transfer and led to its higher reactivity. By the total organic carbon, the absorbance of UV(254), FTIR, the molecular weight distribution and the chemical fractional character analysis, the degradation process of HA was shown to proceed by the disappearance of aromaticity, the increase of hydrophilic fraction and aromatic ring openings into CO(2) and small organic acid. The treated HA showed much lower reactivity toward chlorine and the disinfection byproduct (DBP) formation potential was also greatly reduced. Moreover, it was found that the DBP formation potential more depended on the structure of the intermediates of HA degradation than TOC removal.
Nie
Yulun
Y
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Hu
Chun
C
Zhou
Lei
L
Qu
Jiuhui
J
Wei
Qunshan
Q
Wang
Dongsheng
D
D002384:Catalysis; D002614:Chelating Agents / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D006812:Humic Substances; D006861:Hydrogen Peroxide / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D007202:Indicators and Reagents; D007501:Iron / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D016877:Oxidants / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014466:Ultraviolet Rays; D014961:X-Ray Diffraction
D002614:Chelating Agents; D005290:Ferric Compounds; D006812:Humic Substances; D007202:Indicators and Reagents; D016877:Oxidants; C000499:ferric oxide; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D007501:Iron