油页岩灰基分子筛的制备及对亚甲基蓝的吸附
Synthesis and methyl blue adsorption performance of oil shale ash-based zeolites
石磊 1王倩 1赵晓胜 2刘宏臣 1车远军 1段玉 1李庆1
作者信息
- 1. 西安工程大学环境与化学工程学院,陕西西安 710048
- 2. 沧州师范学院化学与化工系,河北沧州 061001
- 折叠
摘要
针对油页岩灰基分子筛的类型和结构与其吸附染料分子能力间构效关系不明确的问题,以北票油页岩灰(BPA)为原料制备了 NaP1、NaX和NaA三种不同类型的分子筛,并将其用于吸附亚甲基蓝(MB),考察了分子筛用量、MB初始浓度、pH、吸附温度和时间对吸附的影响规律,阐明了分子筛吸附MB过程的吸附机理,明确了不同类型分子筛与其吸附MB能力之间的构效关系.结果表明,分子筛的比表面积和孔结构对其吸附能力影响较大,在最优化吸附条件下,NaP1、NaX和NaA型分子筛对MB的去除率分别为99.7％、94.5％和96.5％,且均具有良好的可再生重复利用性能.吸附过程符合拟二级动力学和Langmuir等温吸附模型.NaP1型分子筛对MB的吸附是自发的、吸热的熵增过程;NaX和NaA型分子筛对MB的吸附是自发的、放热的熵减过程.吸附机理研究表明,静电引力、氢键和孔扩散是分子筛吸附MB过程的主要推动力.可为油页岩灰的资源化利用以及低成本吸附法处理印染废水提供有价值的实践和理论借鉴.
Abstract
The structure-function relationship between the type and structure of the oil shale ash-based zeolite and its ability to adsorb dyes is unclear.NaP1,NaX and NaA zeolites were prepared from Beipiao oil shale ash(BPA)and used to adsorb methylene blue(MB).The effects of zeolite dosage,initial MB concentration,pH,adsorption temperature and time on the MB adsorption performance were investigated,and the adsorption mechanism was revealed.The structure-function relationship between the type of zeolite and its ability to adsorb MB was explored.The results showed that the specific surface area and pore structure of the zeolite have great effects on its adsorption capacity.Under the optimal adsorption conditions,the MB removal percentages by NaP1,NaX and NaA zeolites are 99.7％,94.5％and 96.5％,respectively.The synthesized zeolites have excellent recyclability.The adsorption processes conform to the pseudo-second-order kinetic and the Langmuir isothermal adsorption models.The adsorption thermodynamics results show that the MB adsorption on the NaP1 zeolite is a spontaneous endothermic process of increased entropy while that on the NaX and NaA zeolites is a spontaneous exothermic process of decreased entropy.The study of adsorption mechanism showed that electrostatic attraction,hydrogen bond and pore diffusion are the main driving forces during the MB adsorption on the zeolites.This work can provide valuable practical and theoretical reference for the efficient utilization of oil shale ash and low-cost treatment of dyeing wastewater by adsorption method.
关键词
油页岩灰/分子筛/亚甲基蓝/吸附机理/构效关系Key words
oil shale ash/zeolite/methylene blue/adsorption mechanism/structure-function relationship引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据