Preparation Of Novel Carbon Nanomaterials And The Study Of Adsorption Properties To Organic Pollutants

With our rapid development of plastic manufacture,paper making,printing and dyeing in China,the industrial products are closely related to people's daily life now.And our life becomes more and more colorful.However,driven by the economic interests,some factories neglect the concept of sustainable development and the importance of environmental protection during their production process.The industrial wastewater with a lot of organic pollutants are released out to our environment directly.And some other factories are restricted by technical requirements with simple treatment.They have little idea how dangerous the behavior have.Simply speaking,water contamination around our life is quite serious under the influence of many reasons.Therefore,it is a major issue for our national economy and people's life to control and handle the water contamination.Bisphenol A(BPA)is one of the world's most widely used industrial compounds.It is mainly applied for the production of polycarbonate,epoxy resins,plasticizer,paint and other chemical materials.Also,BPA can be used during the manufacturing process of food packaging,baby bottles,spectacle glasses and so on.But BPA is a kind of endocrine disruptor,which is similar to estrogen.Even at a low dose,it can interfere with the human and animals' reproductive and development,which will cause endocrine disorder and metabolic problems.Otherwise,dye is also a kind of common organic pollutant.The annual production of dyes in China can be very large.But the actual production process and technology standard are still not advanced.It will lead to a serious destruction of aquatic organisms,if our water environment is polluted by organic dyes.And people will also suffer from the danger of dye polluting water.Because of the complex composition and structure of synthetic dyes,it is difficult for us to make dyes degraded.What's more,most of the organic dyes have great toxicity.With the mutagenic,teratogenic and carcinogenic effect,dyes have a strong power to threaten human health.Many works have been reported that adsorption is a common method for wastewater treatment.And at present,lots of scientific researchers in this field are committed to developing the ideal adsorbents,which are lower-cost,environmental-friendly,but of excellent adsorption property.In this paper,we have prepared the magnetic carbon nano-onions(MCNOs)for the adsorption of BPA;Zn-MOFs-GO composites for the adsorption of methylene blue(MB);and pleurotus eryngii derived activated carbon(PEAC)for the adsorption of Congo red(CR),methyl orange(MO)and MB.As reported,CR,MO and MB are three kinds of common dyes being applied in many fields.In addition,we analyze the morphology,structure and some other information of as-prepared adsorbents by using characterization techniques,such as SEM,TEM,Raman,XPS and so on.In the experiment,the factors to adsorption property,adsorption isotherm,adsorption thermodynamics and adsorption kinetics are further investigated.1.Adsorption of BPA onto MCNOs composites.In this work,for the purpose of making an experimental candle,we use iron(III)acetylacetonate as modified reagent and common candle as the raw material.The candle soot was collected from the burning new candle and then subjected to calcination at three temperatures under N2 atmosphere for 2 h.The products obtained at 700?,800?,900°C were denoted as MCNOs-1,MCNOs-2,MCNOs-3,respectively.The as-prepared MCNOs were characterized by SEM,TEM,BET,XRD and XPS analyses.After that,they were further applied as an adsorbent for the removal of bisphenol A(BPA)from aqueous solution.Adsorption of BPA onto the MCNOs was studied with the influence of solution pH,initial concentration of BPA and adsorption time.The results demonstrated that the maximum adsorption capacity of BPA onto the MCNOs-2 was quite high,which implied the good adsorption capacity of his adsorbent.Adsorption isothermal and kinetic data were better described by Langmuir isotherm and pseudo-second-order kinetic model,respectively.And the adsorption process to equilibrium did not cost a long time.2.Adsorption of MB onto Zn-MOFs-GO composites.Graphene oxide(GO)was prepared by modified Hummers method,which was dissolved in a certain amount of N,N-dimethyl formamide(DMF).After well ultrasonic dispersion,we obtained GO/DMF solution.By mixing up the 2-aminoterephthalic acid,acetylenedicarboxylic acid and Zn(OAc)2·2H2O under stirring,we synthesized a kind of flocculent precipitate(Zn-MOFs)at room temperature.Then add the GO/DMF solution slowly to react with Zn-MOFs for a certain time.By centrifugation,washing,vacuum drying,Zn-MOFs-GO composite was fabricated.Then characterize the Zn-MOFs-GO composite by using SEM,TEM and XPS measurement.And the adsorption of MB onto the Zn-MOFs-GO composite was investigated with the influence of solution pH,initial concentration of MB,adsorption time and temperature.These experimental data showed that the Zn-MOFs-GO composite exhibited a superior absorption performance to MB.The process was better fitted by Freundlich isotherm and pseudo-second-order kinetic model.It was also found that a lower temperature was conducive to this adsorption.3.Adsorption of CR,MO and MB onto PEAC composites.We reported a facile and inexpensive method to prepare pleurotus eryngii derived activated carbon(PEAC)using pleurotus eryngii as the raw material.Firstly,using tubular furnace and annealed to get pleurotus eryngii char(PEC).Then a certain mass of PEC power was soaked with a certain volume of KOH solution for some hour.Next,the PEC/KOH mixture was further activated during the thermal treatment process.After washing and drying,PEAC was synthesized.The SEM,TEM,BET,Raman,XPS analysis were carried out to characterize the synthesized PEAC.The prepared PEAC was used as an adsorbent for dyes adsorption,including CR,MO and MB.The effect parameters of dyes adsorption onto PEAC,such as solution pH,initial concentration of dyes,adsorption temperature,contact time were studied.The results indicated that PEAC could exhibit an excellent adsorption performance to these 3 kinds of dyes.As a result,PEAC had an excellent adsorption capacity toward CR,MO and MB.The adsorption process was better tally with the Langmuir model and pseudo-second-order kinetic model.And the adsorption process was an endothermic one.