钝化剂铁粉对Cd(Ⅱ)的吸附特性  

Adsorption properties of passivator zero-valent iron for removal of Cd(Ⅱ)

作　　者：袁钊 尹立新[2,3,4] 施沈杰 徐晓晶 唐强 YUAN Zhao;YIN Lixin;SHI Shenjie;XU Xiaojing;TANG Qiang(School of Rail Transportation,Soochow University,Suzhou,Jiangsu 215131,China;Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210098,China;Jiangsu Research Center for Geotechnical Engineering Technology,Hohai University,Nanjing,Jiangsu 210098,China;College of Economics and Management,Changshu Institute of Technology,Changshu,Jiangsu 215500,China;Suzhou Tonghe Environmental Engineering Co.,Ltd.,Suzhou,Jiangsu 215011,China)

机构地区：[1]苏州大学轨道交通学院,江苏苏州215131 [2]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [3]河海大学江苏省岩土工程技术工程研究中心,江苏南京210098 [4]常熟理工学院经济与管理学院,江苏常熟215500 [5]苏州同和环保工程有限公司,江苏苏州215011

出　　处：《江苏大学学报（自然科学版）》2020年第1期73-80,共8页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51708377);江苏省自然科学基金资助项目(BK20170339);江苏省建设系统科技项目(2016ZD18)

摘　　要：以铁粉为稳定化剂,通过吸附试验,系统分析了多种因素影响下Cd(Ⅱ)在铁粉中的吸附特性;利用吸附等温线、吸附动力学对铁粉吸附Cd(Ⅱ)进行研究,并通过反应前后SEM电镜图和XRD衍射谱图分析吸附反应机理.试验结果表明:铁粉对Cd(Ⅱ)的单位吸附量随初始溶液质量浓度和反应时间的增加呈上升趋势,随铁粉掺量的增加呈下降趋势;初始溶液酸碱度对铁粉吸附Cd(Ⅱ)影响并不大;在Cd(Ⅱ)初始质量浓度为100 mg·L^-1,铁粉掺量为20 g·L^-1,反应时间为48 h的条件下,Cd(Ⅱ)去除率达到94%,平衡吸附量为4.69 mg·g^-1;Langmuir等温线、Freundlich等温线、R-P等温线和颗粒内扩散模型较为符合本反应;谱图分析得出铁粉去除Cd(Ⅱ)主要通过物理吸附和化学吸附,并以化学吸附为主,具体作用形式包括Cd(Ⅱ)被铁粉还原固定,含铁胶体吸附Cd(Ⅱ)共沉淀,以及静电作用等.Iron powder was used as passivator to analyze the adsorption characteristics of iron powder for Cd(Ⅱ)under various key factors through adsorption experiment.The process of Cd(Ⅱ)adsorption by iron powder was investigated through adsorption isotherm and adsorption kinetic models.By scanning electron microscope(SEM)photographs and X-ray diffraction(XRD)spectra,the adsorption mechanism was explored.The experimental results show that unit adsorption amount of iron powder is increased with the increasing of initial solution concentration level and reaction time and is decreased with the increasing of dosage.The initial solution pH has little effect on Cd(Ⅱ)adsorption by iron powder.When the initial solution concentration is 100 mg·L^-1 with dosage of 20 g·L^-1 and reaction time of 48 h,the removal efficiency of Cd(Ⅱ)is 94%with equilibrium adsorption capacity of 4.69 mg·g^-1.Langmuir isotherm,Freundlich isotherm,R-P isotherm and intraparticle diffusion model are consistent with the adsorption process.Mechanism discussion shows that the removal of Cd(Ⅱ)is mostly pushed by the combination of physical adsorption and chemical adsorption by iron powder,while the chemical adsorption is dominant.The specific means include reduction of Cd(Ⅱ)by iron powder,coprecipitation of iron-containing colloid with Cd(Ⅱ)and electrostatic interaction.

关 键 词：铁粉 镉 土壤污染 吸附模型 吸附机理 化学吸附 

分 类 号：TS73[轻工技术与工程—制浆造纸工程]