Study On The Adsorption Of Eu And Sb On Iron-cerium Modified Biochar

In this paper,peanut shells and corn stalk biochar were used as raw materials,cerium nitrate and ferric chloride were used as modifiers,and different modified biochar were obtained by hydrothermal method.The physicochemical properties of the materials were characterized by Fourier transform infrared spectrometer（FT-IR）,X-ray diffraction（XRD）,surface area and porosity analysis（BET）and scanning electron microscope（SEM）.Batch adsorption experiments were conducted to investigate the effects of adsorbent dosage,solution pH,adsorption time and experimental temperature on the adsorption,and The adsorption characteristics were analyzed by adsorption kinetics and isotherms.SEM results shown that the number of folds on the surface of modified biochar increased.BET results shown that the specific surface area ratio of modified biochar（Fe-Ce-PC500,Fe-Ce-CC500 and Fe-Ce-PC300）increased by 9.3,15.8 and 2.3 times,respectively,and the pore size increases by 5.9,10.6 and 2.7 times,respectively.The adsorption properties of modified biochars for Eu and Sb are higher than those of unmodified biochar.Compared with unmodified biochar,the removal rates of Eu（Ⅲ）by modified biochar（Fe-Ce-PC500、Fe-Ce-CC500）were improved by 12%and 16%,respectively,and the removal rate of Sb（Ⅴ）by Fe-Ce-PC300 was 18%higher than that by unmodified biochar.The optimum adsorption conditions of Fe-Ce-PC500 for europium（Ⅲ）were as follows:the pH of solution was 6,adsorption time was 600 min,and experimental temperature was 45℃.The experimental results shown that the adsorption of Eu（Ⅲ）by Fe-Ce-PC500 was better described by the Langmuir isothermal model and the adsorption was monolecular layer,the maximum theoretical adsorption capacity was calculated to be 46.236mg·g^-1.The optimum adsorption conditions of Fe-Ce-CC500 for europium（Ⅲ）were as follows:the pH of solution was 6,adsorption time was 40 min,and experimental temperature was 45℃.The experimental results shown that the adsorption of Eu（Ⅲ）by Fe-Ce-CC500 was better described by the Freundlich isothermal model and the adsorption was multi-molecular layer,the maximum theoretical adsorption capacity was calculated to be 43.748mg·g^-1.The optimum adsorption conditions of Fe-Ce-PC300 for antimony（Ⅴ）were as follows:the pH of solution was 1,adsorption time was 800 min,and experimental temperature was 45℃.The experimental results shown that the adsorption of Sb（Ⅴ）by Fe-Ce-PC300 was better described by the Langmuir isothermal model and the adsorption was monolecular layer,the maximum theoretical adsorption capacity was calculated to be 32.456mg·g^-1.Thermodynamic experiment results shown that the adsorption of the three modified biochar materials was endothermic reaction,and the adsorption process was consistent with pseudo-second-order kinetic model.