摘要
风化煤固定化微生物材料较游离微生物能更好地钝化重金属。研究旨在探究风化煤固定化微生物材料的铅吸附性能及机理,为其污染场地应用提供理论指导和依据。以风化煤固定化微生物材料为对象,通过批量吸附试验系统研究材料的用量、pH、吸附时间和铅溶液质量浓度对其吸附性能的影响,并采用动力学、热力学模型拟合的方式描述铅吸附过程,结合扫描电镜和红外光谱技术对吸附机理进行探究。结果表明,风化煤固定化微生物材料用量为0.4 g/L、pH值为4、吸附时间大于12 h时,在200 mg/L铅溶液中吸附性能最优,最大吸附量达到338 mg/g;拟二级动力学模型和Langmuir模型显示,该吸附过程以化学吸附为主,且铅离子以单分子层的形式排列;热力学分析表明,该反应是自发的吸热反应,温度升高会促进反应的发生。材料表面钙、钠等元素的离子交换作用及羟基、羧基、羰基、酰胺基等活性基团的络合沉淀作用,促进了风化煤固定化微生物材料的铅吸附作用。在铅质量浓度为200 mg/L,材料用量为0.4 g/L、pH值为4、吸附时间大于12 h时,可实现材料吸附性能的最大化。材料表面的Ca、Na等元素与铅的离子交换作用以及羟基、羧基、羰基、酰胺基与铅的络合沉淀作用是其主要作用机制。
Weathered coal-immobilized microbial materials can better passivate heavy metals than free microorganisms.This article aims to explore the lead adsorption performance and mechanism by weathered coal-immobilized microbial materials,with a view to providing theoretical guidance and basis for their application in contaminated sites.In this study,the immobilized microbial materials by weathered coal were taken as the objects,the effects of the amount of adsorbent,pH,adsorption time,and solution concentration on the adsorption performance of lead were systematically studied through batch adsorption experiments.The adsorption process of lead was described by fitting kinetic and thermodynamic models,and the adsorption mechanism was investigated by combining scanning electron microscopy and infrared spectroscopy.The results showed that the optimal adsorption performance was achieved in a lead solution of 200 mg/L with a dosage of 0.4 g/L of weathered coalimmobilized microbial materials,pH=4,and an adsorption time of more than 12 h.The maximum adsorption amount reached 338 mg/g.The pseudo second order kinetic model and Langmuir model showed that the adsorption process was dominated by chemical adsorption,and lead ions were arranged in a single molecular layer.Thermodynamic analysis showed that the reaction was a spontaneous endothermic reaction,and temperature rise promoted the occurrence of the reaction.The ion exchange action of elements such as calcium and sodium,as well as the complexation and precipitation action of active groups such as hydroxyl,carboxyl,carbonyl,and amide groups,promoted the lead adsorption of the materials.The maximum adsorption performance of the materials could be achieved when the lead concentration was 200 mg/L,the dosage of weathered coal-immobilized microbial materials was 0.4 g/L,pH=4,and the adsorption time was more than 12 h.The main adsorption mechanism was the ion exchange action between the elements such as calcium and sodium on the surface of the materials and lead,and the complexatio
作者
焦子乐
李建华
陈潇晶
卢晋晶
郜春花
徐明岗
JIAO Zile;LI Jianhua;CHEN Xiaojing;LU Jinjing;GAO Chunhua;XU Minggang(Institute of Eco-environmental Industry Technology,Shanxi Province Key Laboratory of Soil Environment and Nutrient Resources,Shanxi Agricultural University,Taiyuan 030031,China;College of Resources and Environment,Shanxi Agricultural University,Taigu 030801,China;Institute of Loess Plateau,Shanxi University,Taiyuan 030006,China)
出处
《山西农业科学》
2024年第1期94-100,共7页
Journal of Shanxi Agricultural Sciences
基金
国家重点研发项目(2020YFC1806504-03)
山西省自然科学基金面上项目(202103021224137)
山西省博士来晋奖励项目(SXBYKY2021089)
山西农业大学博士科研启动项目(2021BQ48,2021BQ49)。
关键词
铅污染修复
固定化微生物材料
吸附特性
动力学模型
热力学模型
吸附机制
lead pollution remediation
immobilized microbial materials
adsorption characteristics
kinetic models
thermo⁃dynamic models
adsorption mechanism
