镧钛氧化物介孔毫米球除磷性能与机理
Performance and mechanism of mesoporous La-Ti oxide millispheres for efficient removal of phosphorus
朱文婷 1方渝琪 2宋月 2叶雅男 2田海龙 2黄先锋2
作者信息
- 1. 苏州农业职业技术学院环境工程学院,苏州,215000
- 2. 温州大学生命与环境科学学院,温州,325035
- 折叠
摘要
利用溶胶-凝胶模板法制备了镧钛双金属氧化物介孔毫米球LaxTi1-xO2,通过BET、XRD、SEM、TEM等方法对LaxTi1-xO2进行了系统表征,同时考察了镧钛物质的量比、煅烧温度、初始溶液pH等因素对LaxTi1-xO2除磷效果的影响.结果表明,经400℃煅烧制得的La0.5Ti0.5O2介孔毫米球具有高比表面积(105 m2·g-1)、适宜的介孔结构(平均孔径3.71 nm)、优异的吸附磷酸盐能力,吸附容量达75.8 mg·g-1.La0.5Ti0.5O2除磷性能随La/Ti物质的量比和投量的增加而升高,随pH增加而下降.共存Cl-和NO3-对La0.5Ti0.5O2吸附磷酸盐的影响较小,而SO42-和HCO3-对吸附过程有较大影响.吸附等温线与Langmuir模型高度吻合(R2=0.992),表明La0.5Ti0.5O2对磷酸盐的吸附是单分子层吸附.La0.5Ti0.5O2对磷酸盐的吸附过程遵循准一级(R2=0.978)、准二级动力学模型(R2=0.994),表明其对磷酸盐吸附过程是以化学吸附为主的物理化学吸附.零电荷点、FT-IR、XPS等表征结果表明,La0.5Ti0.5O2通过静电吸引与配体交换反应吸附去除磷.
Abstract
A series of mesoporous LaxTi1-xO2 millispheres were prepared by sol-gel template method.The resultant adsorbents were systematically characterized by means of BET,XRD,SEM and TEM.Effects of La/Ti molar ratio,calcination temperature,initial solution pH on the performance of phosphorus removal by LaxTi1-xO2 millispheres were investigated.The results showed the optimized La0.5Ti0.5O2 prepared at 400 ℃ possessed high specific surface area(105 m2·g-1),suitable mesoporous structure(average pore size of 3.71 nm)and excellent adsorption capacity of 75.8 mg P·g-1.The removal of phosphorus by La0.5Ti0.5O2 increased with the increase of La/Ti molar ratio and La0.5Ti0.5O2 dosage,but decreased with the increase of pH.The coexisting Cl-and NO3-exhibited a little influence on the adsorption of phosphorus,while SO42-and HCO3-showed great effects on adsorption process.The adsorption isotherm was well in agreement with Langmuir model(R2=0.992),indicating that the adsorption of phosphorus by La0.5Ti0.5O2 obeyed monolayer adsorption.The adsorption kinetic of phosphorus followed pseudo-first-order(R2=0.978)and pseudo-second-order kinetic model(R2=0.994),suggesting that the removal of phosphorus by La0.5Ti0.5O2 belonged to a chemical adsorption-dominated physicochemical adsorption.The results of zero charge point measurement,FT-IR and XPS demonstrated the adsorption of phosphorus by La0.5Ti0.5O2 through electrostatic attraction and ligand exchange reaction.
关键词
介孔毫米球/镧钛氧化物/吸附/除磷/配体交换Key words
mesoporous millisphere/La-Ti oxide/adsorption/phosphorus removal/ligand exchange引用本文复制引用
基金项目
国家自然科学基金(52170092)
苏州市科技计划(SNG2023012)
出版年
2024
NETL
NSTL
万方数据