Preparation Of GrapHene-coupling Zero-valent Iron Material And Its Effectiveness In Removing Oxytetracycline

China is the largest country in the use and production of antibiotics.Antibiotic pollution is a potential killer that threatens human health.Its excessive standards have caused pollution problems to become more and more prominent.Exploring the removal technology of oxytetracycline?OTC?pollution has attracted worldwide attention.Grap Hene oxide?Go?is prepared by using oxidized and purified grap Hite powder according to the modified Hummers method,and chemical reduction method is used to reduce grap Hene oxide by ethylenediamine to prepare three-dimensional reduced grap Hene oxide?r GO?,and a one-step liquid p Hase is used Reduction method,using Go and r Go as carriers to couple nano-zero-valent iron materials to grap Hene to prepare a composite material G-n ZVI,through SEM,XRD,XPS and other technologies on the p Hysical form and composition of G-n ZVI,Fe⁰ particles Characterize and analyze the distribution state,material composition and structural characteristics of the material,as well as the adsorption kinetics,adsorption isotherm test and other materials to study the performance of OTC adsorption,and finally the composite material on the influencing factors of tetracycline antibiotic oxytetracycline.1.Properties of composite materialsDuring the preparation of 2G-n ZVI and 3G-n ZVI materials,the surfactant sodium dodecylbenzene sulfonate was added to make the iron in the G-n ZVI material be Fe⁰ particles with a particle size of 1-2 nm and on the surface of the grap Hene sheet.It is well dispersed,more uniform Ly distributed,more uniform in particle size and smaller in size than unmodified Fe0 particles,and there is no obvious agglomeration p Henomenon,which helps Fe⁰ particles to exert greater removal efficiency during the treatment of pollutants.2.Influencing factors of composite materials on OTC in waterThe p Hysical and chemical properties of the wastewater environment?such as temperature,PH,etc.?will affect the removal effect of the material on the OTC.Among them,the PH value has the largest influence,and the temperature has less influence.Among them,the temperature will not only affect the initial reaction rate of OTC in the G-n ZVI removal solution,but also have a greater impact on the removal rate;under neutral-acid conditions,as the p H value decreases,the faster the initial reaction rate.The higher the removal rate;the alkaline conditions will greatly reduce the removal rate of OTC by G-n ZVI,which is not conducive to the degradation reaction;In the investigation of the dose-effect relationship between chemicals and pollutants,it was found that the removal efficiency would increase with the increase of the input amount.The optimal input of 2G-n ZVI is 0.4g/L;the optimal input of 3G-n ZVI is 0.8g/L.3.Adsorption performance of composite materials for OTC in waterLangmuir model and quasi-second-order kinetic model describe the adsorption process of OTC by composite materials.Compared with the single-component Go and ZVI materials,the two composite materials have significantly improved the ability to adsorb OTC(for2G-n ZVI,when C0=100 mg·L^-1,p H=3.0,T=298 K,The theoretical maximum adsorption capacity is 248.475 mg·g^-1;for 3G-n ZVI,when C0=100 mg·L^-1,p H=3.0,T=298 K,the theoretical maximum adsorption capacity is 230.95 mg·g^-1),in a wide range of p H values?p H 3.0-7.0?have shown good adsorption performance.Through comparative analysis of various properties of the material,from the perspective of the safety of the degradation process and the practical significance of the stability of the material,3G-n ZVI material is far superior to 2G-n ZVI material.4.Removal mechanism of oxytetracycline by composite materialsBy comparing XPS and XRD analysis to verify the G-n ZVI spectrum before and after removing OTC pollutants,it was found that grap Hene material can be used as a carrier to inhibit the oxidation of nano-zero-valent iron during pollutant removal and maintain its stability;during the degradation process Among them,grap Hene mainly performs p Hysical adsorption,and zero-valent iron can generate hydroxyl radicals to oxidize OTC.Through the XPS and XRD pattern analysis of the composite material and single nano-zero-valent iron before and after degradation,it is found that there is still a large amount of nano-zero-valent iron in the composite material after degradation,indicating that the composite material is more stable.