Preparation Of Fctional Gaphene And Its Aplication In The Asorption Of Mlti-pollutants

The world is facing the problem of water resource shortage and pollution.How to treat water pollution efficiently and without secondary pollution is a widely concerned research.Graphene is the newest adsorption material with high specific surface area,which can adsorb and remove many kinds of pollutants in wastewater.In this study,magnetic graphene-based adsorbents(m-rGO)were prepared and used to adsorb heavy metals,dyes and mixed pollutants in wastewater.After adsorption,the magnetic adsorbents were separated by external magnetic field,then the recovery and reuse of the adsorbents were realized.The main findings are as follows:(1)Magnetic reduced graphene oxide(m-rGO)was prepared by hydrothermal method,and then characterized by scanning electron microscope(SEM),infrared spectrometer(FTIR),X-ray diffraction(XRD),specific surface area(BET),magnetometer(VSM)and other characterization methods.Based on these data,we demonstrated the chemical structure and the microscopic morphology of m-rGO.It is proved that the prepared m-rGO has both high specific surface area and magnetic property.(2)The adsorption properties and mechanism of lead ion and Rhodamine B were studied.The adsorption capacity of lead ion was up to 188.77 mg/g,for Rhodamine B,it was 218.69 mg/g.The was used to reveal the adsorption kinetics and sorption isotherm model mechanism of the adsorption process.Both the process of lead ion and Rhodamine B were well suited in the model of pseudo-second-order kinetics and the Langmuir isotherm equation.The equilibrium adsorption capacity obtained is in good agreement with the experimental data.(3)The mixed pollutants of Rhodamine B and lead ion were adsorbed and removed by magnetic graphene.Firstly,the optimum adsorption conditions of two single-component pollutants in binary mixture were determined,and then the adsorption performance and mechanism of the adsorbent were studied.An analysis of the adsorption process by means of adsorption kinetics and sorption isotherm models shows that,the adsorption processes of Rhodamine B and lead ions in the binary mixture conformed to the quasi-second-order kinetics of adsorption and Freundlich adsorption isotherm equation.The equilibrium adsorption capacity of Rhodamine B is 222.15 mg/g and that of lead is 210.5 mg/g.The results showed that the adsorbents could remove the binary pollutants simultaneously without reducing the removal efficiency of the single component pollutants.(4)Compared with reduced grapheme oxide,magnetic reduced grapheme oxide has better adsorption capacity,and can be recycled under external magnetic field,which shows the value as the recycling resources.