镧、铈改性沸石对污水除磷性能和机制的比较研究  

Comparative Study of Performance and Mechanism of Lanthanum and Cerium Modified Zeolite on Phosphorus Removal in Wastewater

作　　者：崔有为[1] 李杰[1] 杜兆富[2] 

机构地区：[1]北京工业大学环境与能源工程学院,北京100124 [2]钢铁研究总院功能材料研究所,北京100081

出　　处：《中国稀土学报》2016年第4期460-468,共9页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(51478011;51178004);北京市自然科学基金项目(8132013);北京市属高等学校高层次人才引进与培养计划项目资助

摘　　要：稀土改性沸石除磷作为一种高效的除磷吸附剂已经被广泛地关注。但是,La和Ce改性沸石在吸附性能和除磷机制上的差异却未见报道。通过制备La和Ce改性商业购天然斜发沸石颗粒用于废水除磷,比较了二者的吸附能力、吸附动力学、物理性质、晶型、表面特征。研究表明:经过La和Ce改性的沸石吸附量提高了将近10倍,Ce改性沸石的吸附量略高于La改性沸石的吸附量。动力学拟合结果表明:La改性沸石对磷的吸附更符合伪二级动力学方程,而Ce改性沸石对磷的吸附更符合伪一级动力学。电镜和能谱分析发现Ce的负载量高于La的负载量。La和Ce都堆积在沸石表面,并未浸渍到沸石的孔径中。由于Ce在沸石表面的大量堆积增加了其比表面积,提高了其对磷的吸附能力。La和Ce改性沸石都形成了相同的晶体,二者具有相同的除磷机制。Rare earth modified zeolite as a kind of effective adsorbent on phosphorus removal was widely concerned. But there was little study about comparing adsorption performance and mechanism in phosphorus removal process of lanthanum and cerium modified zeolite. In this study,we synthesized lanthanum modified zeolite and cerium modified zeolite to remove the phosphate. And compared the adsorption capacity and kinetics of the lanthanum and cerium modified zeolite,the physical and chemical properties,crystal type and surface features were also studied. The phosphorus removal experiments showed that after modified with lanthanum or cerium,the adsorption capacity of phosphate was nearly ten times of the former,and the cerium modified zeolite was better. The kinetics study showed that the pseudo second-order model fitted the lanthanum doped zeolite experimental data quite well.While the cerium doped zeolite was more inclined to the pseudo first-order model. The SEM and EDX data showed more cerium than lanthanum doped on the zeolite. And the lanthanum and cerium were all accumulated on the zeolite surface but not in the pores of the zeolite. For the accumulation of the cerium,cerium modified zeolite with larger specific surface area had a better adsorption capacity. From the same crystal of the lanthanum and cerium modified zeolite,we speculated that they have the same mechanism in phosphorus removal process.

关 键 词：La负载 Ce负载 沸石 除磷 吸附 

分 类 号：X703.1[环境科学与工程—环境工程]