腐殖酸吸附水中铀的特性与机理  

On the nature and mechanism of adsorption of U(Ⅵ) by humic acid in the sewage

作　　者：张亚萍[1] 谢水波[1,2] 杨金辉[1] 李仕友[2] 刘迎九[1] 刘金香[2] 顾中华[2] 

机构地区：[1]南华大学污染控制与资源化技术湖南省高校重点实验室,湖南衡阳421001 [2]南华大学铀矿冶生物技术国防重点学科实验室,湖南衡阳421001

出　　处：《安全与环境学报》2012年第4期66-71,共6页Journal of Safety and Environment

基　　金：国家自然科学基金项目(11175081;21177053);湖南省科技计划重点项目(2011SK2015);湖南省研究生创新基金项目(CX2011B376)

摘　　要：通过序批式试验研究了腐殖酸(Humic Acid,HA)对铀的吸附行为及时间、吸附剂用量、铀的初始质量浓度、pH值、温度和共存离子等试验条件对吸附的影响,分析了其热力学和动力学过程,用扫描电镜(SEM)、红外光谱(FT-IR)手段分析了相关吸附机理。结果表明,吸附过程在60min后达到动态平衡,吸附率最高达99%以上。当pH值在5左右时,HA投加量越大,吸附效率越高。体系中HCO3-、H2PO4-的存在对HA吸附U(Ⅵ)有促进作用,而柠檬酸根离子、EDTA2-及Cr6+、Mn2+使HA对U(Ⅵ)的吸附率降低,影响程度与其离子浓度正相关。准二级吸附动力学方程可以较好地描述HA吸附U(Ⅵ)的动力学规律,R2=0.9951。当温度为25℃时,U(Ⅵ)质量浓度与吸附量之间的关系符合Langmuir经验公式,饱和吸附容量为170.94 mg/g。HA吸附U(Ⅵ)前后的IR光谱分析表明,HA主要含有—OH、—COOH、—NH2、—C—N、苯环等结构,推断与U(Ⅵ)相互作用的主要基团为—OH、—C=O、—C—N—、—NH2。This paper is aimed at presenting our research findings of the characteristic features and mechanism of the adsorption of U（ Ⅵ ） by humic acid（HA） in the sewage. To proceed with our research, we have laid out and carried out some static adsorption experiments so as to test and determine the adsorption of U （Ⅵ） by the HA in the sewage. Through experiments, we have attempted to analyze and find the kinetic and adsorption isotherm regulations and made discussions over the mechanism for U（ Ⅵ ） removal by using SEM and FTolR, so as to make clear the effects of the adsorption time, pH value, the initial concentration, the temperature to be used in the experiments, and the coexisting ions, such as HCO3^- , H2PO4^- , NO3^-, SO4^2-, Cr^6＋, Mn^2 ＋, etc. The results indicate that the adsorption equilibrium tends to be achieved in 60 min, and the adsorption rate of U（ Ⅵ ） could be up to as high as 99%. The experimental facts also tell us that the U（ VI ） removal rate tends to increase with the decrease of the dosage of adsorbent HA. In addition, the influence of temperature on the U（ VI ） adsorption proves to be small, though pH value may have a strong effect on the adsorption of U （ VI ）. When pH value is lower than 5, the U （ Ⅵ） removing rate would be accelerated with the increase of pH. However, if the pH is higher than 5, the removal rate turns to drop. Therefore, it can be said that the best adsorption rate （99.73%） can be thought of to be at pH 5. Furthermore, the observed experimental results imply that coexist 10 mmol/L citrate ions and EDTA2- may have strong negative effects on pH value and the adsorption of U （VI）, in the experimental process, in which the U（Ⅵ） removing rate can even turn to decrease from 99.34% to 50.00% and then to 42.15%, respectively. At the same time, some slight positive effects of HCO3 , H2PO4 can also be observed on the adsorption of U（ VI ）. A positive correlation of the effects of the concentrations of such anionics

关 键 词：市政工程 含铀废水 腐殖酸(HA) 吸附性能 共存离子 

分 类 号：X946[环境科学与工程—安全科学] X591