Study On The Preparation And Adsorption Properties Of Magnetic GO-ATP Composites

Dye wastewater has the characteristics of large output,deep pigment,complex composition,high COD,and high toxicity.It is one of the most important and dangerous sources that cause environmental pollution and affect human health.The adsorption method plays an important role in the field of printing and dyeing wastewater treatment because of its simple process and low cost.Adsorbent is the key of the adsorption method.If it can be recycled,its utilization efficiency will be improved and processing cost will be reduced.As a new type of carbon material,graphene oxide has a high specific surface area,rich oxygen-containing functional groups,excellent physical and chemical properties,etc.,which makes it popular in water adsorption applications.However,graphene oxide has the problems of easy stacking and difficult separating,which limits its wide application in practice.Therefore,it is necessary to modify it effectively,so that it can not only maintain excellent adsorption capacity but also be able to be separated from water quickly.The main research contents and conclusions of this article are as follows:1.Magnetic GO-ATP composite was prepared by a solvothermal method.By comparing the adsorption effect of composite materials on methylene blue,the optimal preparation conditions of magnetic GO-ATP were determined as follows:magnetic GO/ATP mass ratio was 1:1.2,GO/Co Fe₂O₄mass ratio was 1:6,synthesis temperature was 180°C,and the synthesis time was 24h.The X-ray diffraction(XRD),specific surface area analyzer,Zeta potentiometer,vibrating sample magnetometer(VSM)were used to characterize the magnetic GO-ATP.The results showed that the magnetic GO-ATP composite was successfully synthesized,and its saturation magnetization was 29.04 emu/g,which had good magnetic separation performance.2.The adsorption experiment of MB was performed with magnetic GO-ATP.The results showed that when the concentration of MB solution was 10 mg·L^-1,the p H value was 7,the adsorption time was 60 min and the magnetic GO-ATP dosage was 0.03 g,the removal efficiency could reach 98.64%.It was found that the adsorption process of the composite material on MB belonged to a monolayer chemical adsorption process on homogeneous surface,through the fitting of sorption kinetics and isotherm models.Meanwhile,the adsorption process was an endothermic and spontaneous reaction process.Throughout the adsorption process,internal diffusion is not the only step to control the rate of adsorption.After adsorption,the magnetic GO-ATP could be efficiently separated and recovered by a magnet,and the recoverable rate was 98.67%.The removal rate for MB could still reach 88.38%after five adsorption-regeneration cycles,indicating that the composite material could be recycled for many times.3.The magnetic GO-ATP was used to adsorb mixed dyes.The results showed that in the mixed dye system,the changes in the effects of adsorbent dosage,p H of solution,adsorption time,and initial concentration of the dye on the adsorption of MB and MG were basically the same as the single dye.The removal rate of magnetic GO-ATP to MB and MG in mixed dyes were lower than in single dye,which indicated that competitive adsorption existsed in the mixed system.In the binary system,the adsorption of MB and MG by magnetic GO-ATP were fitted with the pseudo-second-order kinetic model and the Extended Langmuir model.Magnetic GO-ATP could be efficiently used to adsorb MB and MG mixed dyes.