磷酰基乙酸改性粉煤灰基SBA-15的制备及选择性吸附稀土性能  

Preparation of phosphoryl acetic acid modified fly ash-based SBA-15 and its selective adsorption for rare earth elements

作　　者：王茜 桂晓光 周祥 崔静磊 郭彦霞 程芳琴 WANG Qian;GUI Xiaoguang;ZHOU Xiang;CUI Jinglei;GUO Yanxia;CHENG Fangqin(Institute of Resources and Environmental Engineering,Shanxi University,Taiyuan 030006,Shanxi,China)

机构地区：[1]山西大学资源与环境工程研究所,山西太原030006

出　　处：《精细化工》2021年第11期2359-2367,共9页Fine Chemicals

基　　金：国家自然科学基金项目(U1810205);山西省高等学校科技创新项目(2020L0022)。

摘　　要：以粉煤灰为硅源合成了介孔二氧化硅SBA-15,对其进行磷酰基乙酸(PAA)功能化改性制备了PAA-SBA-15吸附剂,对改性前后的吸附剂进行了XRD、N_(2)吸附-脱附、红外光谱表征。结果显示,改性后吸附剂的孔道保持高度有序。将PAA-SBA-15用于模拟溶液中稀土离子的吸附,发现PAA-SBA-15吸附剂对Eu^(3+)、Gd^(3+)、Tb^(3+)、Nd^(3+)、Sm^(3+)的吸附量分别可达18.6、23.2、21.9、22.6、20.2mg/g。考察了竞争离子Ca^(2+)、Mg^(2+)、Al^(3+)、Fe^(3+)对吸附稀土离子性能的影响。结果显示,Fe^(3+)的存在对PAA-SBA-15吸附稀土离子干扰性最强。吸附动力学和热力学结果显示,PAA-SBA-15对稀土离子的吸附符合准二级动力学和Langmuir等温吸附模型,吸附过程中化学吸附占主导作用。Mesoporous silica SBA-15 was synthesized using fly ash as silicon source,and then PAA-SBA-15 adsorbent was prepared by surface modification of SBA-15 by phosphoryl acetic acid(PAA).The adsorbents before and after modification were characterized by XRD,N_(2) adsorption-desorption and infrared spectrometer.The results showed that the highly ordered pores in the adsorbent remained after modification.The PAA-SBA-15 adsorbent was used to adsorb rare earth ions,and it was found that the adsorption capacity for Eu^(3+),Gd^(3+),Tb^(3+),Nd^(3+),Sm^(3+) reached 18.6,23.2,21.9,22.6,20.2 mg/g,respectively.The effect of competing ions such as Ca^(2+),Mg^(2+),Al^(3+),Fe^(3+)on the adsorption of rare earth ions was studied.The results indicated that the presence of Fe^(3+)had the strongest interference on PAA-SBA-15 adsorption of rare earth ions.Adsorption kinetics and thermodynamics displayed that the adsorption process fitted quasisecond kinetics and Langmuir model,indicating chemical adsorption was dominated in the adsorption process.

关 键 词：SBA-15 稀土离子 吸附 吸附动力学 等温吸附 水处理技术 

分 类 号：O647.3[理学—物理化学] X703[理学—化学]