纳米球状LaAlO3的制备及其在酸性条件下的除氟性能
Preparation of nano-spherical LaAlO3 and its fluoride removal performance under acidic environment
刘京都 1余关龙 2龙志奇 3周璐 2包璞瑞 1滕骏毅 1杜春艳2
作者信息
- 1. 长沙理工大学水利与环境工程学院,湖南长沙 410114
- 2. 长沙理工大学水利与环境工程学院,湖南长沙 410114;洞庭湖水环境治理与生态修复湖南省重点实验室,湖南省环境保护河湖疏浚污染控制工程技术中心,湖南 长沙 410114
- 3. 有研资源环境技术研究院(北京)有限公司,北京 101400
- 折叠
摘要
为实现在较低的pH及煅烧温度下合成表面性能良好的LaAlO3晶相,解决废水的深度除氟问题(＜1.5mg/L),采用共沉-水热法制备了纳米球状钙钛矿LaAlO3,考察了影响LaAlO3表面性能的制备因素,通过SEM(扫描电子显微镜)、XRD(X射线衍射)、ICP-MS(电感耦合等离子体质谱)、BET等分析发现形成碱式碳酸沉淀的水热前体可使Al3+和La3+均匀沉淀、结合紧密,得到LaAlO3的最佳制备条件:共沉淀pH=6,水热温度=160℃,煅烧温度850℃.通过静态吸附实验系统分析了LaAlO3吸附F-的行为,结果表明,LaAlO3可以在酸性(pH＜3)条件下实现深度除氟,在pH=2时,除氟效率达到93.22%.吸附过程符合Langmuir等温吸附模型和准二级动力学模型,属于化学单层吸附、放热反应.在初始氟浓度为200mg/L条件下,8min LaAlO3吸附容量达到53.8mg/g,4h平衡吸附容量可达66.5mg/g.以明矾作为脱附剂,LaAlO3能够在循环4次后仍保持原有90%以上的除氟性能,具有良好的再生性能及实际利用价值.
Abstract
In order to solve the problem of synthesizing LaAlO3 crystalline phase with good surface properties by lowering the calcination temperature at lower pH for application in deep fluoride removal in wastewater(＜1.5mg/L),the nano-spherical perovskite LaAlO3 by co-precipitation hydrothermal method was prepared and the preparation factors affecting the surface properties of LaAlO3 was investigated.It was found by SEM,XRD,ICP-MS and BET that the formation of hydrothermal precursors of alkali carbonic acid precipitation can make Al3+and La3+precipitation more tightly bound and the optimal preparation conditions for LaAlO3 were obtained:co-precipitation pH=6,hydrothermal temperature=160℃and calcination temperature of 850℃.The behavior of F-adsorption by LaAlO3 was analyzed by static adsorption experiments and regeneration experiments systematically,and the results showed that LaAlO3 could achieve deep fluoride removal under acidic(pH＜3)conditions and the fluoride removal rate reached 93.22%at pH=2.The adsorption process conformed to the Langmuir adsorption isotherm model and pseudo-second-order kinetic model,which was a chemical monolayer adsorption with exothermic reaction.Under the condition of initial fluorine concentration of 200mg/L,the adsorption capacity of LaAlO3 adsorption reached 53.8mg/g in 8min and the equilibrium adsorption capacity reached 66.5mg/g in 4h.By using alum as desorbent,LaAlO3 can maintain more than 90%of the original fluoride removal rate after 4 cycles with excellent regeneration performance and high utilization value.
关键词
LaAlO3/含氟废水/深度除氟/吸附剂/纳米双金属氧化物Key words
LaAlO3/fluorinated wastewater/deep defluorination/adsorbent/nano bimetallic oxides引用本文复制引用
基金项目
湖南省教育厅重点项目(21A0188)
湖南省环境保护河湖疏浚污染控制工程技术中心开放基金(EPD202104)
湖南省自然科学基金(2021JJ30728)
湖南省自然科学基金(2022JJ30616)
出版年
2024
国家科技期刊平台
NSTL
万方数据