Adsorption Of Phenolic Pollutants From Aqueous Solution By Functionalized Graphene

Phenolic pollution in environment mainly refers to phenolic compounds polluting water.Phenolic wastewater is one of the world's largest hazardous industrial wastewater,and the range of its pollution extends widely.It is an important cause of water pollution in environment.Phenolic pollutants mainly come from the wastewater released by coal oil refining,gas preparation,and other chemical production process.Part of untreated phenolic wastewater mixed rivers and lakes.Phenolic compounds which contained in wastewater invaded atmosphere,soil and clean water in various forms,eventually great harm caused.Dealing with phenolic wastewater is one of the hotspots in environmental science field.Adsorption is an effective way which has high research and application value in dealing with phenolic wastewater treatment.An ideal adsorbent should have the ability to remove toxic contaminants from environments rapidly and efficiently and environmentally friendly.As a novel carbon material,graphene has a unique two-dimensional monoatomic layer structure,which has many outstanding properties,such as large specific surface area,good electrical conductivity and high mechanical strength.Moreover,the property of its surface could be modified to adjust.These advantages give it a great potential and value of application.The experimental results of this paper are as follows.Firstly,the synthesis of two novel graphene material KH550GO and KH570GO.Taking advantage of the pre-experimental method,two kinds of silane coupling agent(KH550 and KH570)were grafted onto the surface of graphene oxide(GO)respectively,as named KH550GO and KH570GO.Using infrared spectroscopy,scanning electron microscopy,EDS spectroscopy,X-ray photoelectron spectroscopy as characterization methods,the success of material synthesis was proved.Secondly,the comparison of adsorption abilities of GO,KH550GO and KH570GO.Three kinds of representative phenolic organics were selected:phenol,hydroquinone and m-cresol for adsorption test.UV spectra was taken as means of quantitative detection.Compared with GO,the adsorption property of KH570GO(arranging in accordance with the above organic matter order)increased 179%,84%,and 18%.The adsorption abilities of KH550GO enhanced 94%,30%,and 6%.Equilibrium adsorption time of the two new materials was between 4 and 15 min,optimum adsorption pH condition was between 6.5 and 7.5.Finally,exploration of the adsorption model and mechanism of materials.Corresponding to the three materials,Langmuir and Freundlich model fitting was made based on adsorption data.The adsorption of GO was consistent with the Langmuir adsorption model,and KH550GO and KH570GO corresponded with Freundlich adsorption model.Many causes to explain adsorption phenomena were considerred,such as structural effect,steric effect,charge effect and so on.