摘要
该文研究了活性炭对放射性废水中铀的吸附特性,所研究的影响因素包括接触时间、溶液的pH值pHa、铀的初始浓度和实验温度。利用能谱扫描电镜（SEM）、透射电镜（TEM）、X射线能谱（EDS）和红外光谱（FTIR）对活性炭的表面物化性质和表面功能团进行了表征。结果表明,活性炭表面存在羟基官能团并对吸附起重要作用;吸附反应在30min内可以达到平衡;pHa在3~9对吸附影响较大,在3〈pHa〈5时吸附容量和吸附率增大，在5〈pHa〈7时吸附容量和吸附率减小，在7〈pHa〈9时吸附容量和吸附率上升较快；u（Ⅵ）在活性炭上的吸附反应符合Tempkin、Slip和D-R等温模型及准一级动力学方程；吸附反应是自发放热熵增过程。饱和吸附容量为62．50mg·g^-1，吸附率最大为99．23％。
The adsorption of uranium from wastewater onto activated carbon was investigated in batch experiments.Four independent variables, the contact time, solution pHa, initial uranium concentration and temperature, were varied to determine the influence of these parameters on the adsorption of the uranium from water.The activated carbon size were characterized by scanning electron microscopy（SEM）and transmission electron microscopy（TEM）,with the element content characterized by energy dispersive X-ray spectrometer（EDS）and surface functional groups characterized by infrared spectrocopy（FTIR）. The FTIR spectra indicated that hydroxyl groups are present on the surface of the activated carbon and affected the adsorption.The U（Ⅵ）adsorption onto activated carbon reached sorption equilibrium within 30 min.The adsorption of U（Ⅵ）on activated carbon was strongly dependent on the pHain the range of 3.0~9.0.The adsorption capacity and removal percent increase for pHafrom 3to 5,decrease for pHa =5~ 7,and then increase quickly for pHa = 7 ~ 9.The U（Ⅵ）adsorption on activated carbon is well described by apseudo-second-order kinetic model and the Tempkin,Slip,and D-R isotherm models.The sorption reaction is spontaneous,exothermic and increases the entropy.The maxmium adsorption capacity is 62.50mg·g-1.The maxmium removal rate is 99.23%.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2016年第3期312-317,共6页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金资助项目(51578307)
压水堆国家重大专项(2013ZX06002001)
教育部高等学校博士学科点专项科研基金资助项目(20130002130012)
关键词
活性炭
U(Ⅵ)
吸附
放射性废水
activated carbon
U（Ⅵ）
adsorption
radioactive wastewater
