转化方式对粉煤灰地聚物原位转化沸石及其Pb^(2+)吸附性能的影响  

Influence of Conversion Method on In-situ Conversion of Fly Ash Geopolymer to Zeolite and Its Pb^(2+)Adsorption Performance

作　　者：宋学锋[1] 陆伟宁 SONG Xuefeng;LU Weining(School of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,西安710055

出　　处：《材料导报》2023年第6期232-238,共7页Materials Reports

基　　金：陕西省科研攻关项目(2018SF-367)。

摘　　要：本工作以高铝粉煤灰为前驱体,通过碱激发及化学发泡的方式制备了富含类沸石相的多孔粉煤灰地聚物,并以此地聚物为骨架,通过原位转化将类沸石相转化为沸石,得到自支撑类沸石吸附材料。另外,研究了碱热、水热、微波三种原位转化方式下多孔粉煤灰地聚物的矿物组成变化规律、不同原位转化条件下制备的沸石类吸附材料对Pb^(2+)的静态吸附行为。研究结果表明:碱热转化有利于多孔粉煤灰地聚物中的类沸石相原位转化生成沸石相,明显提高了其对Pb^(2+)的吸附容量。碱热转化多孔粉煤灰地聚物对Pb^(2+)的吸附属于単分子层吸附。吸附动力学拟合表明,碱热转化多孔粉煤灰地聚物对Pb^(2+)的吸附方式分为物理吸附和化学吸附。当Pb^(2+)初始浓度为100 mg/L和300 mg/L时,吸附过程以物理吸附为主;当Pb^(2+)初始浓度为500 mg/L时,吸附过程伴随大量化学键形成,化学吸附作用更强。Using high-alumina fly ash as the precursor,the porous fly ash geopolymer rich in zeolitephase was prepared by alkali excitation and chemical foaming.With the geopolymer as the framework,the zeolite-like phase was transformed into zeolite through in-situ transformation to form a self-supporting zeolite-like adsorption material.In addition,this work explores the regulation of the mineral composition of porous fly ash geopolymer under three in-situ conversion modes,alkali-thermal conversion,hydrothermal conversion,and microwave conversion;the static adsorption behavior of zeolite-based adsorbents prepared under different in-situ conversion conditions on Pb^(2+)was also studied.The results show that the alkali-heat conversion is beneficial to the in-situ conversion of the zeolite-like phase to the zeolite phase in the porous fly ash geopolymer,which significantly increases the adsorption capacity for Pb^(2+).The adsorption of Pb^(2+)by the alkali-thermal conversion porous fly ash geopolymer belongs to the single molecular layer adsorption.The adsorption kinetics fitting results show that the adsorption of Pb^(2+)by the alkali-thermal conversion porous fly ash geopolymer can be divided into physical adsorption and chemical adsorption.When the initial concentration of Pb^(2+)is 100 mg/L and 300 mg/L,the adsorption process is dominated by physical adsorption;when the initial concentration of Pb^(2+)is 500 mg/L,the adsorption process is accompanied by the formation of a large number of chemical bonds,and the chemical adsorption effect is stronger.

关 键 词：多孔地聚物 原位转化 沸石 铅离子吸附 

分 类 号：TB321[一般工业技术—材料科学与工程]