摘要
采用液相还原法制备了鼠李糖脂改性纳米零价铁(RL@nZVI),并利用X射线衍射、透射电子显微镜、傅立叶红外光谱等方法对其进行表征;研究pH值、反应时间、干扰离子等因素对纳米材料除铀效果的影响;运用吸附动力学模型及表征等手段,对其修复机理进行解释说明。研究结果表明:鼠李糖脂成功负载于Fe^(0)表面,可以有效提高纳米材料的抗氧化性和分散性,比表面积提高约2.5倍,达到12.30 m^(2)/g;当pH=5,反应时间为30 min时,RL_(0.1)@nZVI与RL_(0.2)@nZVI试验组中铀浓度分别降至33.8,24.4μg/L,达到国家排放标准;不同浓度的金属离子对改性纳米材料去除铀效果有不同程度的影响,Cu^(2+)、Mg^(2+)、Mn^(2+)、Zn^(2+)各试验组平衡铀去除率分别为28.26%,95.82%,93.39%,96.28%;吸附动力学结果表明,准二级动力学方程更适合描述nZVI(R^(2)=0.999)和RL_(0.1)@nZVI(R^(2)=0.998)的吸附过程,该过程中存在化学吸附反应;对吸附后的RL_(0.1)@nZVI进行表征,反应物中U(Ⅳ)与U(Ⅵ)的比例为7∶1,Fe^(2+)与Fe^(3+)的比例约为2∶1,这表明在RL_(0.1)@nZVI修复铀污染地下水过程中发生了氧化还原、吸附及共沉淀反应;RL@nZVI是处理铀污染地下水的理想材料。
In this paper,rhamnolipid modified nanoscale zero-valent iron(RL@nZVI)was prepared by liquid phase reduction method and characterized by X-ray diffraction,transmission electron microscopy,and Fourier infrared spectroscopy.The effects of pH,reaction time,interfering ions and other factors on uranium removal were studied.The adsorption kinetic model and characterization results were used to explain the uranium removal mechanism.The results showed that the successful loading of rhamnolipid on the Fe^(0)surface could effectively improve the oxidation resistance and dispersion of nanomaterials,and the specific surface area was increased by about 2.5 times,reaching 12.30 m^(2)/g.When the pH value was 5 and the reaction time was 30 min,the uranium concentration in the RL_(0.1)@nZVI and RL_(0.2)@nZVI experimental groups was reduced to 33.8μg/L and 24.4μg/L,respectively,which reached the national emission standard.Different concentrations of metal ions had different degrees of influence on the uranium removal,and the equilibrium uranium removal rates of Cu^(2+),Mg^(2+),Mn^(2+)and Zn^(2+)experimental groups were 28.26%,95.82%,93.39%and 96.28%,respectively.The adsorption kinetic results showed that the quasi-second-order kinetic equation was more suitable for describing the adsorption processes of nZVI(R^(2)=0.999)and RL_(0.1)@nZVI(R^(2)=0.998).The RL_(0.1)@nZVI after uranium adsorption was characterized,and the results showed that the ratio of U(Ⅳ)to U(Ⅵ)in the RL_(0.1)@nZVI was 7∶1,and the ratio of Fe^(2+)to Fe^(3+)was about 2∶1,indicating that redox,adsorption and co-precipitation reactions occurred during the remediation of uranium-contaminated groundwater by RL_(0.1)@nZVI.RL@nZVI is an ideal material for treating uranium-contaminated groundwater.
作者
李峰
丁德馨
周函
杨迎春
贺桂成
马建洪
丁洋
胡南
张辉
蒋国清
谭韬
LI Feng;DING Dexin;ZHOU Han;YANG Yingchun;HE Guicheng;MA Jianhong;DING Yang;HU Nan;ZHANG Hui;JIANG Guoqing;TAN Tao(Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy,University of South China,Hengyang,Hunan 421001,China;Hunan Province Key Laboratory of Green Development Technology for Extremely Low Grade Uranium Resources,Hengyang,Hunan 421001,China;Geological and Geographic Information Institute of Hunan Province,Changsha,Hunan 410021,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2024年第1期190-199,共10页
Journal of Mining & Safety Engineering
基金
国家重点研发计划项目(2021YFC2902104)
国家自然科学基金核技术创新联合基金重点项目(U1967210)
国家自然科学基金项目(51974163,52274127,12105138)
湖南省重点领域研发计划重点研发项目(2022SK2077)
湖南省教育厅青年项目(20B510)。
关键词
铀污染地下水
鼠李糖脂
纳米零价铁
吸附
uranium-contaminated groundwater
rhamnolipids
nanoscale zero-valent iron
adsorption
