Preparation And Application Of Magnetic Nanomaterials For Adsorption Of Dey From Solution

With the rapid development of an industrialized global economy,organic dyes have been widely used in many industrial fields.Unfortunately,dyes are hardly destroyed by biodegra-dation due to their complex aromatic molecular structures.Therefore,removal of dyes from wastewater becomes environmentally important.So far,several technologies,including adsorption,flocculation,coagulation,ozonation,membrane filtration,and biological treatment,have been developed for the removal of the dyes from wastewater.Among these methods,adsorption technology has attracted interest as an effective and alternative treatment process due to its simple design,economic properties,and easy operation.Phosphate nanomaterials are not only cheap and readily available but also and has shown excellent good absorption properties for wastewater absorption properties.However,they can not be easily separated after adsorption which would lead to the second pollution to the water system.And adsorption process combined with magnetic separation has been considered as an ideal method which can ensure the magnetic reclaim of the adsorbents after adsorption along with the good recycling properties.Thus,a nano-phosphate adsorption materials combined with magnetic separation will have a certain research value and practical outlook be promising in the fields of research and application for dye removal.In this study,we prepared several nanocomposites which combine the Fe3O4 submicron particles of Fe3O4 particlesmagnetic component,and with phosphate combine to generate composite nanomaterials.The adsorption properties of several dyes from aqueous solutions were a systematically studied of its controllable preparation,characterization,properties of dye adsorption and so on.The study includes the following three parts:1.A novel magnetic composite adsorbent composed of Ba3(PO4)2 nanoflakes and Fe3O4 microsphere(BPF)was prepared by hydrothermal method.The morphology,chemical structure,and magnetic property of BPF were characterized by using techniques,such as SEM,EDS,TEM,SAED,XRD,XPS,PPMS and so on.Adsorption of methyl blue(MB)onto BPF was investigated with respect to pH,temperature,dosage,adsorption time,and initial MB concentration.Kinetics data and adsorption isotherm were better fitted by pseudo-secondorder model and Langmuir equation,respectively.The high adsorption capacity of MB by BPF composite was 334.5mg/g.Moreover,BPF was easily recovered,and the adsorption capacity was approximately 92.3%of the initial saturation adsorption capacity after being used five times.The removal of MB was attributed to the hydrogen bond and ionic interactions.2.Magnetic Sr5(PO4)3(OH)/Fe3O4(SPF)nanorod with rough surfaces was prepared by hydrothermal method and characterized by different techniques,such as SEM,TEM,XRD,XPS and PPMS.The adsorption behavior of Congo red(CR)from aqueous solution onto the as-prepared SPF nanorod was systematically investigated.Adsorption isotherm data indicated that the adsorption of CR onto SPF was monolayer adsorption which matched well with the Langmuir isotherm model.The maximal CR up take by SPF was 396 mg/g in the test.Kinetics parameters were in accord with pseudo-second-order equation.For thermodynamic studies,parameters such as the Gibbs free energy,the enthalpy and the entropy indicated that the adsorption process was spontaneous and exothermic in nature.The removal of CR was attributed to the hydrogen bond and ionic interactions.Moreover,SPF can be easily magnetic separated and reused.The adsorption capacity was approximately 89%of the initial saturation adsorption capacity after being used five times.3.The hybrid magnetic Sr5XBa3X(PO4)3(OH)/Fe3O4(SBPF)nanorod was prepared and characterized using different techniques,such as SEM,EDS,TEM,SAED,HRTEM,XRD,and FT-IR.Adsorption studies of acid fuchsin(AF)from aqueous solution with respect to the pH,temperature,time and initial dye concentration were investigated.The maximal AF up take by SBPF was 1590 mg/g in the test.The Freundlich adsorption model was applied to describe the equilibrium isotherms.Kinetics parameters of the adsorption process indicated that it followed the pseudo-second order equation,and the maximum sorption capacity calculated from the pseudo-second-order rate equation was 909 mg/g which was close to the experimental value.Adsorption thermodynamics study indicated the spontaneous nature and exothermic of the adsorption process.The removal of AF was attributed to the hydrogen bond and ionic interactions.Moreover,SBPF was easily recovered,and the adsorption capacity was approximately 97.7%of the initial saturation adsorption capacity after being used five times.