Study On The Degradation Of 2,4-dichlorophenol By H₂O₂ Catalyzed By Nano-Ag⁰/Fe₃O₄ And Cu⁰/Fe₃O₄

Chlorophenols?CPs?are widely used in medicine,pesticides,preservatives and other industries.They have high toxicity and"three effects".After being discharged into water bodies through various routes,they are harmful to water bodies,aquatic organisms,and The safety of human life.In order to ensure the safety of aquatic organisms and human life,and to make the water body reach a safer state,this paper selects a variety of chlorophenol organic compounds as the research object,and uses the synthesized Nano-bimetallic particles to study its catalytic degradation.The specific research content is as follows:?1?Nano-Ag⁰/Fe₃O₄ catalysts were prepared by solvothermal method,and the reaction temperature,reaction time and filling degree of the reaction kettle were adjusted to prepare better catalysts.The transmission electron microscope?TEM?,EDS spectroscopy,area scanning analysis,X-ray diffractometer?XRD?and infrared analysis?FTIR?were used to characterize and analyze the Nano-Ag⁰/Fe₃O₄ catalyst.The results showed that the Nano-Ag⁰/Fe₃O₄ is silver spherically adhered to nanometer Fe₃O₄and has good dispersibility,their size are between 10-50nm.The best preparation conditions are that the reaction temperature is 180?,the reaction time is 24h,and the reactor filling degree is 70%.On this basis,Nano-Cu⁰/Fe₃O₄ catalyst was successfully prepared.TEM showed that the Cu⁰/Fe₃O₄ catalyst was in the shape of a rod with a diameter of about 200nm,and the overall dispersibility of the catalyst was good.?2?The prepared Nano-Ag⁰/Fe₃O₄ and Cu⁰/Fe₃O₄ catalysts were used to degrade 2,4-DCP,and 30%hydrogen peroxide addition amount,nanobimetal catalyst addition amount,and initial solution were considered by a single factor experimental analysis method,the optimal degradation conditions were obtained,Nano-Ag⁰/Fe₃O₄:30%hydrogen peroxide was added in an amount of 20?L,Nano-Ag⁰/Fe₃O₄ catalyst addition amount is0.04g,pH is 4,reaction temperature is 20-40?,Fe/Ag molar ratio is 3:1,Nano-Cu⁰/Fe₃O₄:30%hydrogen peroxide addition amount is 20?L,The Nano-Cu⁰/Fe₃O₄ catalyst was added in an amount of 0.04 g,the pH is acidic,the reaction temperature was 20-40?,and the Fe/Cu molar ratio was 3:1.Comparing the degradation effect of the two catalysts,the degradation efficiency of Nano-Cu⁰/Fe₃O₄ particles is higher,but the degradation products of Nano-Ag⁰/Fe₃O₄ are more thorough.?3?The mechanism of catalytic degradation of 2,4-DCP by two kinds of nano-bimetal particles was analyzed.Among them,the effect of 2,4-DCP's volatilization loss can be ignored,and the two catalysts'influence on the adsorption of 2,4-DCP is also small,mainly because the nanoparticles catalyze the oxidation of 2,4-DCP by the free radicals generated by H₂O₂.Degradation.Ag and Cu have played a great synergistic role as the second metal during the degradation process.Comparing the degradation mechanisms of the two catalysts,the synergistic catalytic effect of Nano-Ag⁰/Fe₃O₄ makes the degradation of 2,4-DCP more thorough.The final mineralization rate is 78.71%,but the reaction rate is slightly slower.In contrast,Nano-Cu⁰/Fe₃O₄ catalyzes H₂O₂,and the degradation rate is very fast.The degradation is completed in 1-2 minutes,but the mineralization rate is 13.36%.The degradation kinetics model of the process of Nano-Ag⁰/Fe₃O₄ catalytic degradation of 2,4-DCP was analyzed.The fitting results showed that ???had a linear relationship with time t,and the degradation process of 2,4-DCP was in accordance with Second-order kinetic reaction model.The reuse performance and storage performance of the two catalysts are discussed,and it is found that both catalysts have better reuse performance and storage performance.?4?Degradation of the remaining chlorophenols and some organic compounds with the Nano-Ag⁰/Fe₃O₄ and Cu⁰/Fe₃O₄ catalysts.The results show that the two catalysts have a good effect on the degradation of the remaining chlorophenols and p-nitrophenol,while the The effects of p-nitrotoluene,nitrobenzene,and o-chloronitrobenzene are bad,presumably because the benzene ring hydroxyl group has a strong electron-donating ability and is susceptible to oxidation.Finally,the mechanism of two catalysts catalyzing the degradation of chlorophenols and p-nitrophenol by H₂O₂ was analyzed.