Preparation And Adsorption Properties Of Graphene Oxide-Based Composite Gels

With the rapid development of industry,a large amount of industrial wastewater is discharged into the environment.The large amount of toxic dyes,heavy metal ions and organic solvents contained in the wastewater seriously damage the ecological environment and threaten human health.Therefore,researchers have been studying a highly efficient,recyclable,non-polluting functional adsorbent to remove toxic pollutants from the water environment.Many researchers have used the unique advantages of graphene and graphene oxide to synthesize graphene-based composite materials with other materials.These materials have high adsorption efficiency for pollutants in water and show broad potential application in water treatment..Based on graphene-based materials,various types of graphene-based gels have been successfully prepared as adsorbents by mixing graphene oxide,graphene with water-soluble polymer(such as PVA,CS,PEG,etc.).The preparation of various graphene oxide-based composite gels and adsorption properties for toxic dyes,heavy metal ions and organic solvents were carried out.(1)Selecting bio-polymer polyvinyl alcohol(PVA)and graphene oxide(GO)to prepare PVA/GO composite gel material by solution method.Firstly,a series of characterization methods were used to confirm the successful preparation of graphene oxide in the laboratory by improved Hummers method.Then,PVA/GO composite gel was prepared by a simple solution method and characterized by SEM,FTIR and TGA.Characterization result confirmed that PVA and GO were fully combined and prepared a structurally stable and porous composite gel.Then,the bulk adsorption experiment was carried out to investigate the adsorption performance of the composite gel on methylene blue(MB).According to the isothermal adsorption experiment,the influence of external conditions on the adsorption performance,the adsorption kinetics and adsorption thermodynamics results,PVA/GO has excellent adsorption property for MB dye,and the saturated adsorption capacity can reach 83.1mg/g?(2)PVA/GO/CS composite gel microspheres were successfully prepared by mixing polyvinyl alcohol(PVA)and chitosan(CS)with graphene oxide(GO),and used SEM and FTIR.TGA means to characterize the composite material,confirming that the porous gel microspheres were prepared successfully.Then,the bulk adsorption experiment was carried out to explore the optimal conditions of adsorption behavior by changing the external conditions,and the whole adsorption process was studied by isothermal adsorption simulation,thermodynamic simulation and kinetic simulation.The maximum adsorption capacity of the composite gel for Cu(II),Cd(II)and Pb(II)was 120.71mg/g,165.5mg/g and 202.23mg/g respectively.Compared with other adsorption composites,The microspheres have a better adsorption effect on heavy metal ions.(3)Graphene/PEG composite aerogel was successfully prepared with polyethylene glycol(PEG)and graphene oxide(GO)by hydrothermal method,and exploring the optimal concentration of GO dispersion,the optimal mixing ratio of GO/PEG.The prepared composite gel material has a certain mechanical strength,and the shape of the aerogel can be changed by the shape and size of the reaction vessel and the volume of the reaction solution.The prepared composite aerogel has high adsorption capacity for oils and organic solvents,also has good adsorption capacity for toxic dyes and heavy metal ions,.Due to the multi-functional adsorption performance of the composite aerogel,this paper designed a multi-functional finishing agent model for wastewater,which is a mini column moving bed wastewater reactor,it can realize efficient purification of wastewater.The model is expected to play an important role in the future of water treatment.