三种ZnAl-稀有金属LDHs除磷效果对比试验与机理分析
Comparative Experimental Study and Mechanism Analysis on Phosphorus Removal with Three Types of Zn-Al-rare Metal LDHs
吴梦豪 1姜应和 2李大琳1
作者信息
- 1. 武汉理工大学土木工程与建筑学院,武汉 430070
- 2. 武汉理工大学土木工程与建筑学院,武汉 430070;文华学院城市建设工程学部,武汉 430074
- 折叠
摘要
采用共沉淀法制备了高价金属配比为M∶Al=1∶20(M为La、Zr或Ce)的三种ZnAl-稀有金属三元LDHs,表征了它们的晶体结构、微观形貌和元素组成.通过吸附除磷试验,评估了它们的除磷性能,并深入探讨了除磷机制及吸附性能差异的原因.结果表明:三种ZnAl-稀有金属LDHs均成功合成;它们对磷酸盐的吸附量的大小关系为:La-LDHs＞Zr-LDHs＞Ce-LDHs;它们对磷酸盐的吸附以化学吸附为主,涉及静电相互作用、阴离子-金属配位体、层间阴离子交换,且吸附能力受CO32-的影响大;La-LDHs展现出比其他两种LDHs更好的除磷性能,主要原因是镧离子较大的离子半径、舒展的d轨道和吸附剂粗糙的外表面.
Abstract
Three types of ZnAl-rare metal ternary LDHs with M∶Al=1∶20(M=La,Zr,or Ce)were synthesized by co-precipitation,and their crystal structure,micro-morphology,and elemental composition were characterized.The adsorp-tion experiments were carried out to compare their performance in phosphate removal.The mechanisms of phosphate re-moval and the reasons for the differences in their adsorption capacities were analysed in depth.The results indicated that(a)all three LDHs were successfully synthesized;(b)their phosphate adsorption capacities were in the order of La-LDHs＞Zr-LDHs＞Ce-LDHs;(c)the phosphate adsorption was primarily chemical,involving electrostatic interac-tions,anion-metal coordination,and interlayer anion exchange,and their adsorption capacities were significantly inhibited by CO32-;(d)the superior phosphate removal performance of La-LDHs compared to the other two types of LDHs was mainly attributed to the larger ionic radius,more extended d orbitals of lanthanum ions and the rougher adsorbent surface.
关键词
三元LDHs/稀有金属/磷酸盐/吸附/比较Key words
ternary layered double hydroxides/rare metals/phosphates/adsorption/comparison引用本文复制引用
基金项目
路德环境科技股份有限公司科技攻关项目(LDHJ20200102)
出版年
2024
NETL
NSTL
万方数据