Study On Graphene Oxide Grafted Bialdehyde Cellulose And Its Adsorption To Heavy Metals In Water

It is mainly caused by human factors such as mining,exhaust gas discharge,sewage irrigation and the use of heavy metal products exceeding the standard.The increase of heavy metal content in the environment exceeds the normal range,which directly endangers human health and leads to the deterioration of environmental quality.In this paper,the Marcano method is used to prepare graphene oxide through the oxidation of KMn O₄ under the H₂SO₄/H₃PO₄ system.Microcrystalline cellulose is prepared by selective oxidation under acidic conditions,using sodium periodate as an oxidizing agent.The graft experiment of dialdehyde cellulose and graphene oxide was carried out under heterogeneous/homogeneous system?DMF/alkali-urea?.The graft experiment used triethylenetetramine as the graft monomer,cerium ammonium nitrate and Ammonium sulfate is an activator,and the graft reaction is completed by Schiff base reaction and condensation amidation.The products are named GTD-1 and GTD-2.The product is characterized by X-ray diffractometer?XRD?,specific surface area analyzer?BET?,Fourier infrared spectrometer?FTIR?,scanning electron microscope?SEM?and other means.Characterization results show that the grafting reaction is successful.In the heterogeneous system,the grafted product showed a layered structure,while in the homogeneous system,the product showed a porous structure.The adsorption experiment uses GTD-1 and GTD-2 as adsorbents to carry out adsorption experiments on lead ions and copper ions in water.The adsorption experiments show that the adsorbent can reach adsorption equilibrium within 30minutes,which has the advantage of fast adsorption speed.The adsorption process is greatly affected by the p H value of the solution.At low p H values,[H⁺]will inhibit the adsorption of heavy metal ions by the adsorbent.As the p H value increases,when the p H value is equal to 5,the optimal p H is reached.The adsorption capacity of GTD-1 and GTD-2 for lead and copper ions reached 64.4 mg/g,79.6 mg/g,73.7 mg/g,and 91.0 mg/g.The adsorption process of GTD-1 and GTD-2 conforms to the Freundlich isotherm model and quasi-second-order kinetics.In addition,on the reusable surface of the adsorbent,GTD-1 still retains 76.2%and 58.1%removal rate of lead ions and copper ions after four regeneration experiments,and GTD-2 after four regeneration experiments The removal rate of lead ions and copper ions is still68.9%and 51.8%.This paper synthesizes graphene oxide-dialdehyde cellulose under homogeneous and heterogeneous conditions,which expands the application scope of cellulose,makes up for the defects of graphene oxide in the adsorption of heavy metals,and provides a new method for the treatment of heavy metal wastewater Ideas.