十六烷基三甲基溴化铵/壳聚糖复合改性膨润土对含铀废水的去除与机理研究  

Removal and mechanism of uranium containing wastewater by cetyltrimethylammonium bromide/chitosan composite modified bentonite

作　　者：樊小磊 FAN Xiaolei(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;School of Water Resource and Environmental Engineering,East China University of Technology,Nanchang 330013,China;Jiangxi Bureau of Geology,China University of Geosciences,Nanchang 330000,China;Nuclear Industry Eastern China Construction Engineering Group Co.Ltd.,Nanchang 330000,China)

机构地区：[1]东华理工大学、核资源与环境国家重点实验室,江西南昌330013 [2]东华理工大学水资源与环境工程学院,江西南昌330013 [3]江西省地质局,江西南昌330001 [4]核工业华东建设工程集团有限公司,江西南昌330000

出　　处：《中国有色冶金》2023年第2期126-137,共12页China Nonferrous Metallurgy

基　　金：国家自然科学基金资助项目(41162007,41362011)。

摘　　要：天然膨润土直接处理低浓度含铀废水铀去除效果有限,对其进行改性处理后吸附能力会大幅增加,但目前的改性技术较为复杂。本文以十六烷基三甲基溴化铵和壳聚糖为改性材料,成功制备出CTAB/CTS-B吸附材料,并利用SEM、EDS、XRD、XPS、FTIR对其进行表征,重点研究了CTAB/CTS-B对铀的吸附性能及机理。结果表明:CTAB/CTS-B在pH值7.0、用量3 g/L、吸附时间2 h、振动速率180 r/min、室温的条件下对低浓度含铀废水中铀的最大去除率大于99%;吸附过程符合准二级热力学和Elovich动力学方程,吸附行为复合Langmuir方程;热力学分析表明,吸附焓变为负,低温下△G^(0)小于0,高温下△G^(0)大于0,吸附熵变△S^(0)大于0;分析吸附机理表明,离子交换、静电吸附、C—C、C—O、氨基、羟基和羰基在CTAB/CTS-B吸附铀中发挥了重要的作用,经过5次循环对铀的去除仍较好,表明CTAB/CTS-B具有较好的重复使用性。CTAB/CTS-B对低浓度铀废水中铀具有良好吸附能力,而且合成技术相对简单,更适于应用推广。Treating low-uranium wastewater directly by natural bentonite has limited removal efficiency.The adsorption capacity will increase significantly after modification,but the current modification technologies are more complicated.In the paper,CTAB/CTS-B adsorption material was successfully prepared with cetyltrimethylammonium bromide and chitosan as modified materials,and characterized by SEM,EDS,XRD,XPS and FTIR.In this work,the adsorption performance and mechanism of CTAB/CTS-B for uranium were mainly studied.The results showed that the maximum removal rate of CTAB/CTS-B for low-concentration uranium-containing wastewater was more than 99%under the conditions of pH 7,dosage 3 g/L,adsorption time 2 h,rotational speed 180 r/min and room temperature.The adsorption process conforms to the pseudo-second-order kinetics and Elovich kinetics equation,and the adsorption behavior is complex with Langmuir equation.Thermodynamic analysis showed that the adsorption enthalpy changed to negative,△G^(0)>0,adsorption entropy change△S^(0)>0.Analysis of adsorption mechanism showed that ion exchange,electrostatic adsorption,C-C,C-O,amino,hydroxyl and carbonyl played an important role in the adsorption of uranium by CTAB/CTS-B,and the removal of uranium was still good after five cycles,indicating that CTAB/CTS-B has good reusability.CTAB/CTS-B has good adsorption capacity for low-uranium wastewater,and the synthesis technology is relatively simple,which is more suitable for application and promotion.

关 键 词：膨润土 低铀废水 改性技术 十六烷基三甲基溴化铵/壳聚糖复合改性膨润土(CTAB/CTS-B) 吸附材料 吸附机理 吸附性能 吸附成本 

分 类 号：TF88[冶金工程—有色金属冶金] X758[环境科学与工程—环境工程]