| In recent years,with the rapid development of Xinjiang economy,wastewater treatment has facing increasing challenge.Once wastewater containing heavy metal,dye and polymer is directly discharged,the environment will be polluted.Meanwhile,China has put forward higher request: the discharge level of urban sewage treatment plants must be level A or level B according to the national standards GB18918-2002.Therefore,research and develop excellent adsorbent and the technology of wastewater treatment has become an emergency.?-cyclodextrin has played an important role in many fields such as supermolecular chemistry,separation science,biomedicine,catalyst and so on.Cyclodextrin and its derivatives have large cylindrical cavities to form inclusion complexes with hydrolyzed polyacrylamide(HPAM)in order to degrade organic molecules;Graphene and its derivatives have plenty of advantages such as big specific surface area,lots of surface active sites,easy to be modified,low cost and can be prepared as good adsorption materials,which are all because of its special structure.Thus,Fe3O4 magnetic nanopartials loaded cyclodextrin-graphene supermolecular contain new natures and functions and can be used for treatment of HPAM in oil field wastewater.Besides,graphene oxide has a large quantity of oxygen-containing functional groups,which can be used to adsorb polar organic molecule and treat wastewater containing heavy metal by causing combinations with multivalent metal ions through electrostatic attraction and coordination bond.In this paper,hydroxypropyl-?-cyclodextrin-graphene oxide supermolecular(HP-?-CD-GO)was synthesized by using hydroxypropyl-?-cyclodextrin(HP-?-CD),graphene oxide(GO)as raw materials,then loaded with Fe3O4 nanopartials by means of solvothermal method to form hydroxypropyl-?-cyclodextrin-graphene oxide/Fe3O4(HP-?-CD-GO/Fe3O4)magnetic nanocomposites.Fourier transform infrared spectroscopy(FTIR)indicates the successful preparation of HP-?-CD-GO/Fe3O4.Thermogravimetric analysis(TGA)indicates the quality proportion of HP-?-CD,GO and Fe3O4 in HP-?-CD-GO/Fe3O4 magnetic nanocomposites is 35 %,25 % and 40 %,respectively.Scanning electron microscope analysis(SEM)indicates HP-?-CD-GO/Fe3O4 magnetic nanocomposites are spherical.The modification of HP-?-CD-GO decreased the surface area of Fe3O4.The magnetic nanocomposites have good dispersibility in aqueous solution.Particle size of HP-?-CD-GO/Fe3O4 is in the range of 40~50 nm.Vibrating sample magnetometer analysis(VSM)indicates HP-?-CD-GO/Fe3O4 has superparamagnetism,and its magnetization intensity is 62 emu/g.Because treating a high concentration of HPAM by means of Fenton oxidation was ineffective,the optimal conditions of treating HPAM by means of “Fenton oxidation-adsoption” two-step method has also been studied.The results indicates the under the optimal conditions,the removal of 400 mg/L HPAM can reach 87.8 %.By exploring the factors of pH value,adsorption temperature,adsorption time,adsorbent dosage and heavy metal ion concentration,the adsorption of HP-?-CD-GO/Fe3O4 on Pb2+,Cu2+ has been studied.The results indicates the adsorption of HP-?-CD-GO/Fe3O4 on Pb2+,Cu2+ accorded with Freundlich equation.After three repeated adsorption,the adsorption rate of HP-?-CD-GO/Fe3O4 on Pb2+,Cu2+ is still above 85% and 83%,respectively. |
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