赤泥与沼渣制备颗粒复合材料及其对氨氮的吸附效果研究  

Research on Preparation of Granular Composite from Red Mud and Biogas Slag and Its Adsorption Effect on Ammonia Nitrogen

作　　者：罗昕 吴丽萍 张婷[2] 刘克学 彭星 易志刚 龚天成 杨天学[2] 黄启飞[2] LUO Xin;WU Liping;ZHANG Ting;LIU Kexue;PENG Xing;YI Zhigang;GONG Tiancheng;YANG Tianxue;HUANG Qifei(School of Environmental and Municipal Engineering,Tianjin Chengjian University,Tianjin 300384,China;State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Hunan Renhe Environmental Corporation,Changsha 410153,China)

机构地区：[1]天津城建大学环境与市政工程学院,天津300384 [2]中国环境科学研究院,环境基准标准与风险管控全国重点实验室,北京100012 [3]湖南仁和环境股份有限公司,湖南长沙410153

出　　处：《环境科学研究》2025年第2期407-418,共12页Research of Environmental Sciences

基　　金：广东省环保专项资金项目(粤财资环[2023]12号);黄河流域生态保护和高质量发展联合研究项目(No.2022-YRUC-01-050205-03);国家重点研发计划项目(No.2020YFD1100301-04)。

摘　　要：肥料化是批量消纳赤泥的重要方式,但氮素含量低是制约其应用的瓶颈。为提升赤泥的利用量,并解决吸附材料在实际工程应用中难回收的问题。该研究向赤泥中掺入沼渣进行共热解,制备成型颗粒状复合材料并对模拟沼液溶液中的氨氮进行富集。采用SEM、BET、FTIR和XPS等表征手段,结合吸附动力学模型和等温吸附模型分析其吸附机理。结果表明:①当制备条件为沼渣占比≤25%且热解温度≥400℃时,复合材料具备造粒成型的可行性。②沼渣占比为25%、热解温度为600℃时,制备的复合材料对氨氮吸附效果最佳,材料对氨氮的理论最大吸附量可达6.8141 mg/g。伪二阶动力学模型与Langmuir等温吸附模型均能更好地模拟材料的吸附过程。③热解后,材料的比表面积和平均孔径分别由15.2677 m^(2)/g、12.7495 nm增至28.9365m^(2)/g、14.9315 nm,表面存在金属羟基、C-O和C=O等含氧官能团,这说明热解提升了材料的比表面积且优化了孔径结构,并生成了更多活性含氧官能团,有效提高了材料对氨氮的吸附性能。研究显示,沼渣与赤泥共热解可制备具氨氮吸附性能的复合材料,材料主要通过离子交换、官能团反应、静电引力和孔隙填充实现对氨氮的吸附,研究结果为赤泥和沼渣的资源化利用及易回收吸附材料的制备提供了理论与技术支持。Fertilization is an important method for reducing red mud in bulk,but its low nitrogen content significantly limits its application.To enhance the utilization of red mud and address the challenge of recovering adsorbent materials in engineering applications,biogas slag was added to red mud for co-pyrolysis to prepare molded granular composites to increase ammonia nitrogen content in a simulated methane solution in this study.The adsorption mechanism was analyzed using SEM,BET,FTIR and XPS characterization techniques,combined with adsorption kinetics and isotherm models.The results indicated that:(1)When the preparation conditions include biogas slag content≤25%and a pyrolysis temperature of≥400℃,the composite material was feasible for granulation molding.(2)At a biogas slag content of 25%,and a pyrolysis temperature of 600℃,the composite material exhibited optimal ammonia nitrogen adsorption,with a theoretical maximum adsorption capacity of 6.8141 mg/g.Both pseudo-second-order kinetics and Langmuir isothermal modeling were employed to analyze the adsorption mechanism.(3)After pyrolysis,the specific surface area and average pore size of the material increased from 15.2677 m^(2)/g and 12.7495 nm to 28.9365 m^(2)/g and 14.9315 nm,respectively,with the presence of metal hydroxyls and oxygen-containing functional groups such as C-O and C=O on the surface.The results demonstrate that pyrolysis increased the specific surface area,optimized the pore size distribution of the material,and generated additional active oxygen-containing functional groups,thereby significantly enhancing the material's adsorption capacity for ammonia nitrogen.The study demonstrates that composites with ammonia nitrogen adsorption capabilities can be prepared by co-pyrolysis of digestate mixed with red mud.The adsorption of ammonia nitrogen on the material primarily occurred through ion exchange,functional group reaction,electrostatic attraction and pore filling.These findings provide theoretical and technical support for utilizing red m

关 键 词：赤泥 沼渣 复合材料 共热解 氨氮 

分 类 号：X705[环境科学与工程—环境工程]