Mechanism For Fenton Reaction Based On Iron Phosphate Induced By Benzoquinones Under Visible Light

Heterogeneous light-assisted Fenton technology is the inheritance and development of homogeneous Fenton technology,which is one of the most promising wastewater treatment technologies for high concentration organic wastewater.Iron phosphate in waste lithium iron phosphate,which can not be utilized at high value,is expected to be a low-cost,pollution-free and excellent cyclic iron source.The conversion of Fe^Ⅲ/Fe^Ⅱon the surface of iron phosphate is promoted by the properties of benzoquinones that generate photohydrating electrons under visible light excitation.The efficient degradation for the target pollutants is finally achieved.The effects of benzoquinones on the degradation of OrangeⅡby homogeneous Fenton under visible light was compared.The release and transformation of iron ions in iron phosphate system induced by benzoquinones under visible light was discussed.The mechanism for degradation of OrangeⅡby Fenton based on iron phosphate induced by benzoquinones under visible light was studied.Some research conclusions were as follows:1.It was found that visible light illumination,benzoquinone type and benzoquinone concentration had great influence on the catalytic degradation of OrangeⅡin the benzoquinones-homogeneous light-assisted Fenton system.The degradation efficiency of OrangeⅡwas the highest when the concentration of1,4-Benzoquinone was greater than（or equal to）0.2 mmol·L^-1in different reaction systems.In the visible light illumination range of 32308 lux-161540 lux,degradation efficiency of the reaction system to OrangeⅡgradually increased with the increase of illumination.The main active group for the degradation of target pollutants system was·OH in the reaction system.2.In benzoquinones-induced iron phosphate system,the release and transformation of iron ions was studied under visible light.Among the four quinone systems,（2-Chloro-1,4-benzoquinone,1,4-Benzoquinone,Methylbenzoquinone and2,5-Dimethylquinone）2-Chloro-1,4-benzoquinone-visible light-iron phosphate system had the highest utilization rate of photons.In the system of benzoquinones-visible light-iron phosphate-hydrogen peroxide,the degradation ability of OrangeⅡincreased with the increase of illumination in the range of 32308lux-161540 lux.The addition of 2-Chloro-1,4-benzoquinone to the reaction system had excellently accelerated the·OH generation and its own mineralization.3.The mechanism of OrangeⅡdegradation for Fenton based on iron phosphate induced by benzoquinones under visible light was proved.The2-Chloro-1,4-benzoquinone-visible-iron phosphate hydrogen peroxide system and1,4-Benzoquinone-visible-iron phosphate hydrogen peroxide system had high catalytic degradation performance towards OrangeⅡ.In the reaction system,iron phosphate can be used as a stable source and sink of iron ions.It had high structural and chemical reproducibility after recycling...