The Magnetic Heterogeneous Fenton-like Reaction Catalyzes The Degradation Of Methylene Blue And Ofloxacin

The magnetic heterogeneous Fenton system greatly improved the use of traditional Fentont system reagents in large amounts,high effluent color,the reaction requires acidic conditions and the production of a large number of iron-containing sludge defects,and due to the magnetic properties of the catalyst,can achieve rapid solid-liquid separation,These years have caused widespread concern.With the development of industry,the treatment of dye wastewater has become a research hotspot.Drugs and personal care products?PPCPs?containing various organic groups?such as antibiotics,hormones,antimicrobial agents,synthetic musks,etc.?have become serious environmental problems due to their continuous investment and potential threats to the ecological environment and human health.Dyestuff wastewater and PPCPs wastewater are difficult to biodegrade,have the characteristics of toxicity and"triple effect",and traditional sewage treatment methods are ineffective.In this study,the azo dye methylene blue?MB?and the antibiotic ofloxacin?OFLX?were used as target contaminants.The magnetic nanocomposites MZF@SiO₂ and HZO/CeO₂ containing hafnium silicon particles were used to catalyze the formation of magnetic heterogeneities.The Fenton system undergoes degradation reaction,and some innovative conclusions are drawn:?1?MZF@SiO₂ is prepared by hydrolyzing tetraethylorthosilicate?TEOS?and used as a catalyst for Fenton-like reaction to degrade MB wastewater,which is better for MB.The removal rate,and has a higher removal rate of COD,increased the biodegradability of dye wastewater.?2?Preparation of CeO₂/MZFS by impregnation method,used it as a catalyst for Fenton-like reaction degradation of OFLX wastewater,and achieved better Effect.?3?The magnetic nanocomposite MZF@SiO₂ and the hafnium-containing silicon magnetic particles CeO₂/MZFS have unique functions and advantages in solid-liquid separation,adsorption,and recycling,and are excellent multifunctional materials.As a new type of Fenton reaction catalyst,magnetic nanocomposite MZF@SiO₂has high catalytic activity and can effectively degrade methylene blue printing and dyeing wastewater.The factors affecting the degradation are optimized.The optimal conditions are as follows:Initial MB concentration is 100 mg/L,MB solution volume is50 mL,temperature is 303 K,catalyst MZF@SiO₂ is added in an amount of 1 g/L,H₂O₂?15wt%?is added in a volume of 4 mL.After 120 min of reaction,the degradation rate of MB is up to 94.8%.The COD removal rate can reach 97%at 1440 min.The magnetic nano-composite MZF@SiO₂ is relatively stable,and the the metal leaching is less after the reaction.Reuse experiments have shown that MZF@SiO₂ can be reused multiple times.The magnetic nanocomposite MZF@SiO₂ has unique functions and advantages in solid-liquid separation,adsorption and regeneration,and is an excellent multifunctional material.The results of free radical determination experiments show that the active material of the reaction system is hydroxyl radical.The CeO₂/MZFS was prepared by impregnation method,and the preparation conditions were optimized by comparing the catalytic properties.When the rhodium loading was 7%,the immersion time was 30 min,the frying time was 20 min,the calcination temperature was 473 K,and the calcination time was 80 min,the best catalytic performance was achieved.For the prepared CeO₂/MZFS containing silicon germanium particles,SEM,TEM,XRD,FTIR,XPS and VSM were used to characterize the microstructure,sample composition,element valence and magnetic properties.The results showed that the material was a surface.The fluffy,irregularly spherical particles have gaps between the particles and have a specific surface area of169 m²/g as measured by BET.CeO₂/MZFS is a nanoparticle composed of spinel-structured Fe-MNPs and fluorite-structured CeO₂.CeO₂/MZFS exhibits good paramagnetism,which is advantageous for solid-liquid separation and reuse.The heterogeneous Fenton reaction of hydrogen peroxide was catalyzed by CeO₂/MZFS as a catalyst.The effects of various factors such as the amount of hydrogen peroxide,the amount of CeO₂/MZFS used,and the temperature of the Fenton-like reaction were investigated.The results showed that for 50 mg/L OFLX,the best degradation conditions:temperature 303 K,hydrogen peroxide 4 mL,CeO₂/MZFS 1g/L.Under this condition,the reaction rate of OFLX was up to 82.7%for 120 min.The catalyst was a highly efficient Fenton-like catalyst.The kinetics of the degradation data was fitted by the trial method.It was found that the degradation process of OFLX conformed to the pseudo first-order kinetic model and the reaction was activated.Energy Ea=22.2 kJ/mol<40 kJ/mol,the degradation reaction can be carried out at room temperature.The CeO₂/MZFS has good stability and still has catalytic activity after six times of cyclic use.It can be known from the tert-butanol radical quenching experiment and EPR scanning that the degradation system uses H₂O₂ catalyzed by CeO₂/MZFS to generate hydroxyl radicals and utilizes hydrogen peroxide.Extremely strong hydroxyl radicals contribute to the degradation of OFLX.