Study On The Adsorption And Removal Of Cobalt From Wastewater By Graphene Oxide/Silicon Based Hybrid Membrane

New energy companies have recently been promoted as a new industry in the country and the world.Due to the large number of discarded new energy battery treatment problems,according to statistics,about 70% of China’s cobalt is used for new energy battery production.Cobalt ore contains only 0.02% cobalt.On the other hand,with the development of industry,a large amount of cobalt-containing wastewater is discharged every day,causing different degrees of pollution and damage to the environment and humans.The treatment has become a topic of concern to human beings,and the recycling of cobalt is also a technical problem that enterprises need to overcome.At present for the cobalt in removal of waste water is mainly the traditional chemical precipitation,solvent extraction and adsorption,etc.,but the cost is very expensive,even easy to cause secondary pollution,so this study attempts to sol-gel method successfully created a new kind of graphene oxide/silica hybrid film,not only simple preparation process,low cost,and will not cause pollution to the environment,the heavy metal cobalt can be recycled,is a kind of new green materials.In the first step of this experiment,improved Hummers method was used to successfully produce graphene oxide,the sol-gel method was used to prepare graphene oxide / silicon hybrid films with different ratios of KH-792 and graphene oxide,adsorption experiments were carried out under different conditions of p H,adsorption time,solution concentration and adsorption temperature.As a result,it was found that the ratio D was 1: 3（oxidation when p H = 5,adsorption temperature was 45℃,and initial concentration was 80 mg / L Graphene: KH-792 = 25mg: 75mg）The best adsorption effect,the adsorption amount reached 2.3mg / g.The adsorption process of cobalt ions follows a Lagergren quasi-second-order kinetic model.The entire adsorption process includes physical adsorption of pores and chemical adsorption of surface groups.The adsorption process conforms to the Freundlich adsorption isotherm model.Cobalt ion adsorption parameters 1 / n are in the range of 0.1 to 0.5,which indicates that the graphene oxide / silicon-based hybrid film can easily adsorb cobalt ions.Through thermodynamic model fitting analysis,it was found that the adsorption of cobalt ions by the graphene oxide / silicon-based hybrid film is a spontaneous endothermic process.The influence of different ions on the adsorption effect was also studied,and it was found that the graphene oxide /silicon-based hybrid film had good selectivity for the adsorption of cobalt ions.Finally,an adsorption experiment was performed to desorb the adsorbed graphene oxide / silicon hybrid film in low-concentration H₂SO₄,HCl,HNO₃,and EDTA-2Na solutions.The desorption effect was the best under HCl conditions,ratio D（1: 3）The resolution of low-concentration HCl is over 60%.