Preparation Of Fe₃O₄-reduced Graphene Oxide Nanocomposite And Its Adsorption Properties For Arsanilic Acid

Arsanilic acid compounds can kill harmful bacteria in poultry,and improve the pigmentation of poultry products.It has been widely used in feed additives for livestock and poultry.However,the metabolic rate of arsanilic acid compounds is very low in poultry,and most of them will flow into the environment in its original form,and be transformed into inorganic arsenic forms with stronger toxicity and wider mobility through microbial and nonmicrobial degradation,thereby destroying the environment.At present,experts and scholars at home and abroad have mastered a variety of ways and methods to remove arsanilic acid in the environment through many years of research,but these methods have their own advantages and disadvantages.The adsorption method has become a common technology for the treatment of environmental pollution arsanilic acid due to its simple and easy operation,large capacity,high efficiency,high economic benefits,and wide application range.At present,the common adsorbents have the disadvantages of slow mass transfer,small specific surface area,and difficult recovery.Therefore,the development of new and efficient adsorbents has been widely concerned.In this paper,based on the unique adsorption properties of reduced graphene oxide?r GO?and magnetic metal oxide Fe₃O₄ for arsanilic acid,a new carbon-based metal oxide nanocomposite was prepared to make up for the shortcomings of the weak adsorption performance of arsanilic acid by traditional adsorbents.The main research advances are as follows:?1?The modified Hummers method is used to prepare composite materials,the main raw material is graphene oxide,and the Fe₃O₄-rGO nanocomposite material?Fe₃O₄@G?is prepared by one-pot hydrothermal method.The composite materials were characterized by Fourier Tranform Infrared Spectroscopy,X-ray Diffraction,X-ray Photoelectron Spectroscopy,Transmission Electron Microscope.The results showed that Fe₃O₄@G was successfully compounded;?2?Fe₃O₄@G is used as an adsorbent for arsanilic acid.The experimental values of the adsorption capacity of Fe₃O₄,rGO and Fe₃O₄@G for arsanilic acid were 107.2 ± 6.1 mg g^-1,150.5 ± 12.3 mg g^-1 and 313.7 ± 11.2 mg g^-1.Obviously,the adsorption capacity of Fe₃O₄@G for arsanilic acid is significantly better than the sum of Fe₃O₄ and r GO;the adsorption process is not affected by the initial solution p H at 3-6 and ammonia nitrogen?NH4+-N?concentration up to 1000 mg L^-1;the contact time of Fe₃O₄@G with the solution has reached basically equilibrium within 15 minutes;Langmuir and Freundlich isotherm curves were fitted to the adsorption process of arsanilic acid by Fe₃O₄@G,as well as adsorption kinetics and thermodynamics studies.The results show that the adsorption of arsanilic acid follows the Langmuir isotherm and a quasi-second-order dynamic model,which is a spontaneous endothermic process.