| Pb2+,Cd2+ and other heavy metal pollution in drinking water is becoming more and more serious with the development of industry.Among the various methods of removing heavy metals,adsorption is the main method to remove heavy metals because of its simple equipment,easy operation and low operation cost.However,due to the narrow scope of application of pH,the selectivity is relatively poor,and the adsorption capacity is low,which will directly affect the removal efficiency of heavy metals such as Pb2+,Cd2+ and so on.Because of its high specific surface area and high density of active sites,the adsorbent has high removal efficiency of heavy metal ions.However,nano size adsorbents are usually difficult to fix,difficult to separate,and difficult to recycle.Therefore,to explore the design of the adsorbent should be able to maintain the material can not only retain the excellent performance of heavy metal ions,but also to solve its limitations in the use of.At present the research on nano materials mainly through modification of active groups in the nano carrier,the active groups on the hydroxyl,carboxyl and sulfonic acid group and Pb2+,Cd2+ and other heavy metal exchange so as to achieve the effect of the removal.Therefore,it is the focus of this study to use the synthesized nano adsorbent in the actual water environment.This text focused on the preparation of environmental nanomaterials,as well as its adsorption properties and adsorption mechanism of Pb2+,Cd2+ heavy metals in water.Specific contents are as follows:A new adsorbent,Fe3O4 sulfonated magnetic nanoparticle(Fe3O4-SO3H MNP),was developed for heavy metal ions removal from water,which could be effectively separated from the solution owing to the superparamagnetic property.The nanoparticles can be used to remove heavy metal ions due to the additional active site,"sulfo-group",introduced by the AMPS branches grafted onto the iron oxide.The as-synthesized materials were characterized by SEM,TEM,FT-IR and BET.The FTIR,XPS and Zeta potential were used to describe the adsorption mechanism.The Fe3O4-SO3H MNPs showed rapid removal for Pb2+ and Cd2+ with maximum of adsorption capacity of 108.93 and 80.9 mg/g,respectively,at 25?.The adsorption isotherms for Pb2+and Cd2+ fitted better with Langmuir than Freundlich models,indicated that the processes of the removal of Pb2+ and Cd2+ could follow a kind of similar adsorption manner.The adsorption kinetic was consistent with pseudo-second-order model.Furthermore,the reuse experiments results showed the adsorbent might have potential in treating heavy metal ions pollution in water.The sorption of cadmium in the aqueous solution on the g-C3N4-Fe3O4 magnetic nanoparticle with good recyclability was investigated.The as-prepared g-C3N4_Fe3O4 was characterized by SEM,TEM,TGA,FT-IR,and XPS,respectively.The FT-IR and XPS reveal surface complexion mechanism.The g-C3N4-Fe3O4 exhibits significantly enhanced capacity for Cd2+ from the water compared with g-C3N4.Various influencing factors been taken into account in sorption,such as the pH,sorption time,the initial concentration of the Cd2+,the effect of interfering ions,temperature.These experiments were proved that the mechanism was related with the formation of complexation and ion exchange.The g-C3N4-Fe3O4 had improved Cd2+removal efficiency with a capacity of mg/g under initial Cd2+ concentration of 100 mg/L.Compared with pseudo-second-order model,the adsorption kinetic was better fitted with pseudo-second-order model.The adsorption isotherm of the nanoparticle was fitted with Freundlich model.Thermodynamic parameters were also measured to prove that the process of sorption was exothermic and spontaneous.Moreover,under the action of external magnetic field,the g=C3N4-Fe3O4 could achieve rapid separation.In a word,this is a clever approach to a settle the pollution of cadmium in water.EDTA modified organic chicken,in the high concentration of cadmium ion solution,cadmium ions could be highly efficient adsorption.As the material has more carboxyl groups,the increase of the active site provides greater possibilities for the adsorption of cadmium ions.The basic characterization of SEM and TEM on unmodified chicken feathers and modified EDTA feather.Through the characterization of FT-IR,we can see that EDTA was successfully modified on feather.Compared with the two kinds of materials,it could be found that the modified EDTA had more prominent advantages in the adsorption performance.At 25 C,the initial cadmium ion concentration is 700mg/L,the adsorption capacity could reach 580mg/g,and by fitting,EDTA-feather was in line with the Freundlich model for the adsorption of cadmium ions,and could achieve rapid adsorption.Due to its low cost,practical applicability can be considered. |
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