摘要
为探究土壤胶体对放射性核素锶的吸附机制,选取典型无机矿物蒙脱土和腐殖酸制备有机-无机复合胶体,并研究了其对锶的吸附性能.实验结果表明,人工复合体的腐殖酸负载量可达到2.97%,并且添加腐殖酸会改变蒙脱土的形貌.复合体对锶的吸附量达到6.86mg/g,通过对复合体吸附锶的动力学拟合发现,吸附过程更符合二级动力学模型.吸附过程在10min后到达平衡,低温时去除率更高,15℃时为72.29%.当pH值由5增加到9时,去除率的变化范围在1%~2%之间.而离子强度对吸附有明显的影响,0.1mol/L时去除率较0.001mol/L时的去除率同比下降20%~60%.同时去除率随有机物浓度的增大而提高,从0到60mg/L时去除率快速增长,60mg/L时去除率为75.36%,随后去除率增长进入平缓期.
In order to explore the adsorption mechanism of soil colloids on radionuclide strontium,montmorillonite,one of the typical inorganic minerals,and humic acid were selected to prepare for an organic-inorganic complex,and to explore the adsorption properties.It was found that the humic acid loaded on the complex with a loading of 2.97% can change the morphology of montmorillonite.The adsorption capacity of the artificial complex for strontium was up to 6.86mg/g.By fitting the kinetics of the adsorption of strontium on the complex,the adsorption process was found to be more in line with the second-order kinetic model with the adsorption equilibrium time of 10min.The removal rate was high at low temperature of 15℃ with a rate of 72.29%.When the pH increased from 5 to 9,the removal rate varied between 1%~2%.Ionic strength had a significant effect on adsorption with the removal rate at 0.1mol/L,which was obviously lower than 0.001mol/L with a decreasing rate of 20%~60%.Meanwhile,the removal rate increased with the increasing concentration of humic acid.The removal rate increased rapidly from 0 to 60mg/L,and the highest rate reached 75.36% at 60mg/L,then the rate reached an equilibrium.
作者
刘冰逸
罗敏
邵阳
郑楠
徐殿斗
刘志明
马玲玲
LIU Bing-yi;LUO Min;SHAO Yang;ZHENG Nan;XU Dian-dou;LIU Zhi-ming;MA Ling-ling(Division of Nuclear Technology and Application,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;College of Chemical Engineering,State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology,Beijing 100029,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2021年第9期4204-4210,共7页
China Environmental Science
基金
国家自然科学基金项目(U1932103,11875266,U1832212,91643206)。
关键词
有机-无机复合体
锶
吸附
蒙脱土
腐殖酸
organic-inorganic complex
strontium
adsorption
montmorillonite
humic acid
