Study On The Catalytic Degradation Of Tetracycline Hydrochloride By Modified Iron Oxyhydroxide/graphene Oxide Composite Material

With the large-scale development of livestock and poultry breeding industry in China,the amount of residual antibiotics' aquaculture wastewater is increasing.Due to the resistance and accumulation,antibiotics cannot be effectively removed from wastewater by traditional sewage treatment processes.At present,photocatalytic oxidation technology has become a hot spot for antibiotic treatment in aquaculture wastewater due to its high reaction efficiency,complete degradation and no secondary pollution.In recent years,due to its stable physical and chemical properties and high surface area,iron oxyhydroxide has been widely used in the field of environmental pollution control and repair.Studies have been shown that the degradation of tetracycline by pure FeOOH has the disadvantages of long reaction time and poor treatment efiect.FeOOH,as a functional material with great development potential,needs further development in the treatment of antibiotic wastewater.Graphene oxide(GO)has been widely used in wastewater treatment due to its unique physical and chemical properties and has achieved certain efiects.However,pure GO materials greatly limit their application due to their easy agglomeration and insolubility.Therefore,by modifying GO,it can not only fully amplify its advantages,but also effectively suppress its inadequacies,greatly improving its application potential.For this reason,the hydrothermal synthesis method was used to prepare the iron oxyhydroxide and graphene oxide composites(Brij30/FeOOH/GO)modified by the surfactant Brij30 and the crystal phase,morphology and optical properties of the composites were studied.The research contents mainly include the following three aspects:1)adsorption removal of tetracycline hydrochloride(TCH)by Brij 3 0/FeOOH/GO;2)catalysis of TCH by Brij30/a-FeOOH/GO(Brij30-Gth-GO)+H2O2 system Degradation study;3)Study on catalytic degradation of TCH by Brij30/p-FeOOH/GO(Brij30-Aka-GO)+H2O2 system.The research results can provide theoretical basis for the research and development of FeOOH and its composite materials as environmental functional materials.The main findings of this work are as follows:(1)The SEM results showed that the GO surface was uneven and wrinkles were present.After Brij30/a-FeOOH(Brij30-Gth)and Brij30/?-FeOOH(Brij30-Aka)were loaded with GO,the basic morphology did not change signiticantly and the morphology was finer.XRD results showed that after loading GO with Brij30-Gth and Brin30-Aka,the characteristic peaks of GO disappeared,and the peaks of Brij30-Gth and Brij30-Aka changed,but the difference was not obvious.The DRS results show that the forbidden band of Brij30-Aka-GO and Brij30-Gth-GO are:1.59eV and 1.5 leV,respectively,and the forbidden band width is reduced,which enhances the visible light response capability of the composite and the separation ability of electron-hole pairs.(2)The study on the adsorption of TCH by Brij30-Gth,Brij30-Gth-GO,Brij30-Aka and Brij30-Aka-GO indicate the theory of the equilibrium adsorption amounts(Qe)on Brij30-Gth,Brij30-Gth-GO,Brij30-Aka and Brij30-Aka-GO were 51.23,55.02,59.28 and 66.11 mg·g-1,respectively.The adsorption process satisfies the pesudo-secondary kinetic model and belongs to the chemisorption process.Adsorption isotherms showed that the maximum adsorption capacities of Brij30-Gth,Brij30-Gth-GO,Brij30-Aka and Brij30-Aka-GO were 125,00,144.92,138.89 and 149.25 mg·g-1,respectively.Brij30-Gth and Brij30-Gth-GO are more in line with the Langmuir model,and adsorption is a single molecule that has been adsorbed.Brij30-Aka and Brij30-Aka-GO are more suitable for the Freundlich model,indicating that Brij30-Aka and Brij30-Aka-GO belong to multi-molecular layer adsorption.Brij30-Gth,Brij30-Gth-GO,Brij30-Aka and Brij30-Aka-GO have good adsorption effects on TCH under neutral and weakly acidic conditions.The adsorption effect is best when the adsorbent dosage is 0.5·g-1.The effect of ion type and intensity on the adsorption effect is not significant.(3)The results of visible light photocatalytic degradation show that the catalytic effect of Brij30-Gth-GO and Brij30-Aka-GO is better than that of Brij30-Gth and Brij30-Aka.In addition,the addition of H2O2 was useful to improve the degradation.All four catalysts were in accordance with the quasi-first-order kinetic model.The reaction rate constants of Brij30-Gth-GO and Brij30-Aka-GO when H2O2 was added(K1=0.4433 and 0.4430 min')were twice as high as when H2O2 was not added(K1=0.1747 and 0.1647 min-1).The results of UV-Vis spectroscopy indicated that the benzene ring structure of TCH was destroyed,and the epoxidation was gradually opened.Some functional groups on the benzene ring were removed and other intermediate products were formed.The main role of Brij30-Gth-GO in the degradation of TCH is·O2-which during the degradation of TCH by Brij30-Aka-GO is·O2-and h+.The reusability results show that all four catalysts have good reusability and the loading of GO increases the stability of the catalyst.