U(Ⅵ)在土壤中Freundlich线性吸附临界值  

The linear adsorption critical value of U(Ⅵ) in soil for Freundlich model

作　　者：朱君[1] 李婷 陈超[1] 谢添 张艾明[1] ZHU Jun;LI Ting;CHEN Chao;XIE Tian;ZHANG Ai-Ming(Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology,China Institute for Radiation Protection,Taiyuan 030006,China)

机构地区：[1]中国辐射防护研究院核环境模拟与评价技术重点实验室,太原030006

出　　处：《四川大学学报（自然科学版）》2020年第3期559-563,共5页Journal of Sichuan University(Natural Science Edition)

摘　　要：选择甘肃嘉峪关地区砂土、粘土两种代表性土壤介质,采用静态吸附实验,研究了U(Ⅵ)的线性吸附临界值.实验结果表明:U(Ⅵ)在砂土、粘土中的平衡吸附等温线均符合Freundlich模型. U(Ⅵ)-砂土体系,平衡浓度在0~7.72×10-4 mol·L-1时,吸附等温线趋近于线性,分配系数是等温线斜率KF为16 mL·g-1;平衡浓度在7.72×10-4~5.17×10-3 mol·L-1时,等温线指数α为1.78,吸附平衡参数KF为4.12 L·g-1,分配系数从19.74 mL·g-1增加至71.25 mL·g-1,线性吸附临界值为7.72×10-4 mol·L-1. U(Ⅵ)-粘土体系,平衡浓度在0~7.50×10-4 mol·L-1时,吸附等温线趋近于线性,分配系数是等温线斜率KF为46 mL·g-1;平衡浓度在7.50×10-4~2.72×10-3 mol·L-1时,等温线指数α为1.89,吸附平衡参数KF为27.39 L·g-1,分配系数从79.08 mL·g-1增加至144.73 mL·g-1,线性吸附临界值为7.50×10-4 mol·L-1.The linear adsorption critical values of U(Ⅵ) in sand and clay collected in Jiayuguan area, Gansu Province as typical soil mediums were studied by static adsorption experiments. The experimental results show that the equilibrium adsorption isotherms of U(Ⅵ) in sand and clay both conform to the Freundlich model. The linear adsorption critical value is 7.72×10-4 mol·L-1 in a U(Ⅵ)-sand system. When the equilibrium concentration is 0~7.72×10-4 mol·L-1, the adsorption isotherm is linear and the distribution coefficient corresponding to the isotherm slope KF is equal to 16 mL·g-1. When the equilibrium concentration is 7.72×10-4~5.17×10-3 mol·L-1with the isotherm index α being 1.78 and the adsorption equilibrium parameter KF being 4.12 L·g-1, the distribution coefficient increases from 19.74 mL·g-1 to 71.25 mL·g-1. For a U(Ⅵ)-clay system, the linear adsorption critical value is 7.50×10-4 mol·L-1. When the equilibrium concentration is 0~7.50×10-4 mol·L-1, the adsorption isotherm is linear and the distribution coefficient corresponding to the isotherm slope KFis equal to 46 mL·g-1. When the equilibrium concentration is 7.50×10-4~2.72×10-3 mol·L-1 with the isotherm index α being 1.89 and the adsorption equilibrium parameter KF being 27.39 L·g-1, the distribution coefficient increases from 79.08 mL·g-1 to 144.73 mL·g-1.

关 键 词：砂土 粘土 U(Ⅵ) FREUNDLICH模型 分配系数 线性吸附临界值 

分 类 号：X52[环境科学与工程—环境工程]