| In recent years,the discharge of pesticide wastewater has caused a serious impact on the environment,which has attracted more and more attention.The application of adsorbents with excellent adsorption properties to remove pesticides in wastewater has a wide application prospect.This paper studies the graphene aerogels matrix composite material adsorption of pesticides in water by adsorption process and adsorption mechanism is discussed,and evaluated the graphene aerogels adsorption material used for the feasibility of pesticide wastewater treatment.The research contents of this paper include the following four parts:?1?Graphene oxide were prepared by improving the Hummers method,and carboxyl chitosan of load in the surface of graphene oxide,eventually carboxymethyl chitosan-oxidized graphene aerogels?CM-CS@GA?adsorption material were prepared by freezing drying.The CM-CS@GA was characterized by X-ray Diffraction?XRD?,Fourier Transform Infrared spectra?FT-IR?and Scanning Electron Microscopy?SEM?,Transmission Electron Microscope?TEM?,Brunner-Emmet-Teller measurements?BET?,the optimum catalytic conditions of CM-CS@GA such as pH,temperature,initial contaminant concentration,adsorb time,reused times were explored and the adsorption mechanism was discussed.Research shows that:CM-CS@GA under the conditions of:pH 5.0,catalyst dosage is 0.075 g·L-1,adsorb time 100 min,the adsorption kinetics of the adsorption process is secondary model,after the adsorption isotherm data fitting more accord with the Langmuir adsorption isotherm models,at this point,the maximum adsorption capacity can reach 585.7 mg·g-1,almost the same in the adsorption quantity reusable about 30 times.?2?Graphene oxide were prepared by improving the Hummers method,the resulting graphene oxide was cross-linked with cyclodextrin,and then the cyclodextrin-oxidized graphene aerogel?CD-GA?was prepared by freeze-drying technology.The CD-GA was characterized by X-ray Diffraction?XRD?,Fourier Transform Infrared spectra?FT-IR?and Scanning Electron Microscopy?SEM?,Raman spectra,Brunner-Emmet-Teller measurements?BET?and the optimum adsorb conditions of CD-GA such as pH,temperature,initial contaminant concentration,adsorption time,reused times were explored and the adsorption mechanism was discussed.Research shows that:at pH 3.0,catalyst dosage is0.009 g·L-1,the maximal adsorption capacity can reach 841.4 mg·g-1 after 100 min,the adsorbent adsorption dynamics model for adsorption process is matching for secondary model,adsorption isotherm models for the Langmuir model,adsorbent after 30 times repeated use,its largest adsorption capacity basically remain unchanged.?3?carboxyl carbon nanotubes were prepared through the study of the carboxylation reaction,and graphene oxide prepared by modified Hummers method and the carboxyl carbon nanotubes-oxidized graphene aerogels?CNTs-GA?were prepared by freeze-drying technology.X-ray diffraction?XRD?,Fourier transform infrared spectra?FT-IR?,Transmission electron microscopy?TEM?and Scannig electron microscopy?SEM?are used to compare the structural properties of CNTs-GA and the optimum adsorb conditions of CNTs-GA such as pH,temperature,initial contaminant concentration,adsorption time,reused times were explored and the adsorption mechanism was discussed.Research shows that:at pH 8.0,catalyst dosage is 0.070 g·L-1,90 min achieves the adsorption equilibrium adsorption,the adsorption process in line with the secondary adsorption dynamic model and adsorption isotherm model is closer to the Freundlich adsorption isotherm model,the maximum adsorption capacity can reach 378.5 mg·g-1,keep a constant number of reusable adsorption quantity to 15 times.?4?tert-butyl calixarene were prepared by aldol reaction,then preparation of graphene oxide and crosslinking of tert-butyl calixarenes composite together,finally,calixarenes-oxidized graphene aerogels?TC-GA?were prepared by freeze-drying technology.The TC-GA was characterized by X-ray Diffraction?XRD?,Fourier Transform Infrared spectra?FT-IR?and Scanning Electron Microscopy?SEM?,and the optimum adsorb conditions of TC-GA such as pH,temperature,initial contaminant concentration,adsorption time,reused times were explored and the adsorption mechanism was discussed.Research shows that:under the conditions of pH 3.0,catalyst dosage is 0.050 g·L-1,after 90 min,the adsorption can achieve balance,the maximum adsorption capacity can reach 369.4 mg·g-1,the adsorption kinetics model of adsorption process conforms to the secondary model,adsorption isotherm fitting for the Langmuir adsorption isotherm models,the adsorbent can be repeated use about 15 times. |
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