粉煤灰提铝残渣制备4A分子筛及Cu(Ⅱ)吸附研究
Study on adsorption of Cu(Ⅱ)on 4A zeolite synthesized by aluminum extraction residue by fly ash
赵世永 1肖雨辰 1马清清 2杨珍妮 1王纪镇 1樊晓萍1
作者信息
- 1. 西安科技大学化学与化工学院,陕西西安 710054
- 2. 山西紫金矿业有限公司,山西忻州 034000
- 折叠
摘要
4A分子筛由于其优异的阳离子交换能力,成为处理重金属废水优良的吸附材料.为了达到以废治废的目的,以粉煤灰酸法提铝残渣为原料制备地质聚合物,再经水热原位转化合成体型化4A分子筛.采用XRD、FT-IR、SEM、BET、TGA等手段对4A沸石进行表征,探讨吸附时间、Cu(Ⅱ)初始浓度、吸附剂用量及溶液pH对其吸附性能的影响,并结合动力学方程和吸附等温线模型对其吸附过程进行研究.结果表明,所合成的4A分子筛孔隙发达且微孔含量较多,总比表面积为71.85 m2/g,其中微孔比表面积为53.91 m2/g,微孔孔径主要集中在1.3 nm左右.体型化4A分子筛吸附Cu(Ⅱ)的最佳条件为吸附时间为240 min、Cu(Ⅱ)初始质量浓度为100 mg/L、吸附剂用量为2.0 g/L、溶液pH为6～9,此时吸附量为32.97 mg/g,Cu(Ⅱ)的去除率可达65.93%.吸附过程符合准二级动力学模型,以化学吸附为主.Langmuir模型拟合效果较好,表明Cu(Ⅱ)在合成4A沸石上的吸附过程为单分子层吸附,且拟合得到的Cu(Ⅱ)的最大吸附量为37.05 mg/g.
Abstract
The 4A zeolite has become an excellent adsorption material for the treatment of heavy metal wastewater,due to its good cation-exchange ability.In order to achieve the goal of"using waste treat waste",the geopolymer was prepared from the aluminum extraction residue by fly ash,and then the shaped 4A zeolite was synthesized by hydrothermal in-situ conver-sion.The 4A zeolite was characterized by XRD,FT-IR,SEM,BET,TGA.The effects of adsorption time,initial concentration of Cu(Ⅱ),amount of adsorbent and pH value of solution on its adsorption properties were investigated,and the adsorption process was studied by combining the kinetic equation and adsorption isotherm model.The results showed that the synthe-sized 4A zeolite had developed pores and more micropores.The total specific surface area was 71.85 m2/g,of which the spe-cific surface area of micropores was 53.91 m2/g,and the micropores were mainly concentrated in about 1.3 nm.The optimal conditions for adsorption of Cu(Ⅱ)by the shaped 4A zeolite were as follows:the adsorption time was 240 min,the initial concentration of Cu(Ⅱ)was 100 mg/L,the amount of adsorbent was 2.0 g/L,and pH was 6～9,the adsorption capacity could achieve 32.97 mg/g,and the removal efficiency of Cu(Ⅱ)was 65.93%.The adsorption process conformed to the pseudo-second order kinetic model,which was mainly chemisorption.Langmuir model had better fitting effect,indicating that the adsorption process of Cu(Ⅱ)on synthetic 4A zeolite was monolayer absorption,and the maximum adsorption ca-pacity of Cu(Ⅱ)obtained by fitting was 37.05 mg/g.
关键词
粉煤灰提铝残渣/体型化4A分子筛/Cu(Ⅱ)吸附/准二级动力学模型/Langmuir模型Key words
aluminum extraction residue by fly ash/shaped 4A zeolite/Cu(Ⅱ)adsorption/pseudo-second order kinetics equation/Langmuir model引用本文复制引用
出版年
2024
NETL
NSTL
万方数据