改性蛭石和木本泥炭对水体氨氮的吸附特性比较  

Ammonia nitrogen adsorption characteristics in aqueous solution by modified vermiculite and woody peat

作　　者：杨晓婷 段晓阳 张靖宇 王悦[2] 石生伟 YANG Xiao-ting;DUAN Xiao-yang;ZHANG Jing-yu;WANG Yue;SHI Sheng-wei(College of Biological and Resource Environment,Beijing University of Agriculture,Beijing 102206,China;Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]北京农学院生物与资源环境学院,北京102206 [2]中国农业科学院农业环境与可持续发展研究所,北京100081

出　　处：《南方农业学报》2025年第1期192-203,共12页Journal of Southern Agriculture

基　　金：国家自然科学基金项目(32172778);北京高等教育学会教改项目(5046516654/013)。

摘　　要：【目的】研究改性蛭石和木本泥炭对水体氨氮的吸附性能及机理,筛选适宜的水体氨氮吸附材料,为快速高效解决氨氮废水污染问题提供科学参考。【方法】以天然蛭石、5和7 mol/L硫酸改性蛭石及木本泥炭为研究对象,通过吸附试验、电镜扫描和傅里叶变换红外光谱分析不同材料对水体铵态氮(NH_(4)^(+)-N)的吸附特性及机理。【结果】不同蛭石材料对水体NH_(4)^(+)-N的吸附过程具有快速吸附、缓慢平衡的特点。天然蛭石在酸改性过程中被破坏部分微孔结构,增大了比表面积和平均孔径,但7 mol/L硫酸改性蛭石的比表面积和总孔隙体积低于5 mol/L硫酸改性蛭石。相比天然蛭石,5和7 mol/L硫酸改性蛭石的准一级动力学模型吸附速率常数(k_(1))分别提高2.09和1.45倍,平衡吸附量(q_(e))分别提高3.39和1.86倍,液膜扩散速率常数(k_(a))分别提高1.27和1.00倍。木本泥炭吸附水体NH_(4)^(+)-N的平衡时间较长,k_(1)低于2种酸改性蛭石,但q_(e)仅次于5 mol/L硫酸改性蛭石。4种材料对水体NH_(4)^(+)-N的吸附过程以单分子吸附为主,其等温吸附过程采用Langmuir模型的拟合效率优于Freundlich模型。蛭石系列材料主要依赖于固体材料表面性质和孔隙结构决定的物理吸附过程,其中k_(1)和最大吸附量(q_(m))与材料比表面积呈显著正相关(P<0.05),木本泥炭则依赖于活性官能团与NH_(4)^(+)-N之间的化学反应。【结论】基于多个吸附指标和材料来源可获得性的比较,建议5 mol/L硫酸改性蛭石和木本泥炭作为废水氨氮污染治理的优选吸附材料。【Objective】This experiments were performed to explore the ammonia nitrogen(NH_(4)^(+)-N)aqueous adsorption characteristics and mechanism by modified vermiculite and woody peat,identify suitable materials for the removal of ammonia nitrogen from aqueous adsorption,which could provide scientific basis for the efficient and rapid treatment of ammonia nitrogen contaminated wastewater.【Method】Natural vermiculite,5 and 7 mol/L sulfuric acid-modified vermiculite and woody peat were selected as research materials.The characteristics and mechanisms of ammonia nitrogen aqueous adsorption were analyzed according to results from adsorption experiment by common soil conditioners,scanning electron microscope and the Fourier infrared spectrogram.【Result】The adsorption process of NH_(4)^(+)-N in aqueous solution by different vermiculite materials was characterized by fast adsorption and slow equilibrium.Microcellular structure of natural vermiculite was partially destroyed during the acid modification process,and the specific surface area and average pore diameter were increased.The specific surface area and total pore volume for 7 mol/L sulfuric acid-modified vermiculite were much lower than those under 5 mol/L sulfuric acid-modified vermiculite.Compared with natural vermiculite,adsorption rate constants(k_(1))from quasi-primary kinetic model for 5 and 7 mol/L sulfuric acid-modified vermiculite were increased by 2.09 and 1.45 times,the equilibrium adsorption amounts(q_(e))were increased by 3.39 and 1.86 times,and liquid-film diffusion rate constants(k_(a))were increased by 1.27 and 1.00 times respectively.The equilibrium time of adsorption of NH_(4)^(+)-N by woody peat was longer,k_(1) was lower than that of 2 acid-modified vermiculites,but q_(e) was second only to 5 mol/L sulfuric acid-modified vermiculite.The adsorption processes of 4 materials were primarily monolayer adsorption,the fitting efficiency of Langmuir model was better than Freundlich model in isothermal adsorption process.The physical adsorption proce

关 键 词：氨氮吸附 天然蛭石 酸改性蛭石 木本泥炭 

分 类 号：S181.3[农业科学—农业基础科学]