Study on the removal mechanism of Zn(Ⅱ)and Pb(Ⅱ)by magnetic flake nZVI-Fe3O4
In response to the increasingly serious problem of heavy metal pollution in water bodies,engineering magnetic nanoparticles are widely used in wastewater treatment and remediation.In order to reduce the environmental pollution during the material preparation process,it is of great significance to improve its practicality in environmental protection technology.In this experiment,a new type of magnetic flake zero valent iron ferric oxide(nZVI-Fe3O4)with fissure structure was prepared by disproportionation.The physicochemical properties and structure of the material were characterized by multiple characterization techniques.The effects of pH,temperature,and the initial concentration of heavy metal ion solution on the removal efficiency of Zn(Ⅱ)and Pb(Ⅱ)by nZVI-Fe3O4 were studied.The experimental results showed that the removal of Pb(Ⅱ)and Zn(Ⅱ)by nZVI-Fe3O4 reached an equilibrium state in about 60 min.Under the conditions of a solution pH of 6,temperature of 25 ℃,and a dosage of 1 g/L of nZVI-Fe3O4,nZVI-Fe3O4 can reduce Zn(Ⅱ)and Pb(Ⅱ)in 10 mg/L simulated wastewater to trace levels within 5～30 minutes.As the pH value of the solution decreased,the adsorption efficiency of nZVI-Fe3O4 on Pb(Ⅱ)decreased.The research results indicated that the removal process of nZVI-Fe3O4 followed the Langmuir model,indicating that it was a chemical adsorption process,and the maximum adsorption capacity of Zn(Ⅱ)was 13.52 mg/g,while the maximum adsorption capacity of Pb(Ⅱ)was 26.50 mg/g.Thermodynamic studies had shown that the removal process was spontaneous adsorption.The research results showed that nZVI-Fe3O4 mainly enriched Zn(Ⅱ)and Pb(Ⅱ)through adsorption co-precipitation.nZVI-Fe3O4 can be recovered through an external magnetic field,and experiments had shown that nZVI-Fe3O4 had good application prospects in removing Pb(Ⅱ)and Zn(Ⅱ)in wastewater treatment.
nano zero valent ironmaterial modificationheavy metal pollutionlead ionzinc ion
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