对硝基苯酚和重金属在高炉水淬渣上的竞争吸附研究  

Competitive adsorption of p-nitrophenol and heavy metals on water-quenched blast furnace slag

作　　者：王哲[1,2] 徐毅[3] 黄国和[2] 安春江[4] 陈莉荣[1] 张思思[1] WANG Zhe;XU Yi;HUANG Guo-he;AN Chun-jiang;CHEN Li-rong;ZHANG Si-si(School of Energy and Environment, Inner Mongolia of Science and Technology, Baotou 014010, China;Chinese Academy for Environmental planning, Ministry of Environmental Protection, Beijing 100012, China;MOE Key Laboratory of Regional Energy and Environmental Systems Optimization, Environmental Research Academy, North China Electric Power University, Beijing 102206, China;Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, Saskatchewan, Canada S4S 0A2)

机构地区：[1]内蒙古科技大学能源与环境学院,内蒙古包头014010 [2]华北电力大学环境研究院,区域能源系统优化教育部重点实验室,北京102206 [3]环境保护部环境规划院,北京100012 [4]里贾纳大学,能源、环境和可持续发展研究所,加拿大里贾纳萨斯喀彻温省S4S0A2

出　　处：《中国环境科学》2016年第12期3686-3695,共10页China Environmental Science

基　　金：教育部重点项目(311013)

摘　　要：以高炉水淬渣(WBFS)为吸附剂,对水体中的对硝基苯酚(p-NP)和重金属进行单一吸附和竞争吸附的研究,从吸附等温线、吸附动力学和热力学等方面分析其吸附特性和机理.结果表明:相对于p-NP,重金属离子在竞争条件下居优势地位,重金属离子对p-NP的竞争吸附作用依次为Cu^(2+)>Cd^(2+)>Zn^(2+).高炉水淬渣对p-NP的吸附符合Freundlich模型,而重金属离子的吸附与Langmuir吸附模型拟合较好,D-R模型计算的p-NP在各系统中吸附能量分别为-7.53、-7.07、-7.96以及-7.86k J/mol,表明高炉水淬渣吸附p-NP的过程中以物理吸附为主,而重金属离子则以化学吸附和离子交换为主.动力学曲线显示在二元体系下p-NP的吸附速率下降,吸附达到平衡的时间延长,而竞争组分的存在对Cu^(2+)、Cd^(2+)、Zn^(2+)达到平衡的时间基本无影响.高炉水淬渣对Cu^(2+)、Cd^(2+)、Zn^(2+)表现出更高的亲和力和选择性.无论是单一吸附还是竞争吸附,p-NP和Cu^(2+)、Cd^(2+)、Zn^(2+)均符合伪二级动力学方程.?G值随着温度的升高而逐渐降低,说明高炉水淬渣对p-NP和Cu^(2+)、Cd^(2+)、Zn^(2+)吸附的自发性与温度成正比,属于吸热熵增的过程.Single component and competitive adsorption of p-nitrophenol(p-NP)and heavy metals on water-quenchedblast furnace slag(WBFS)were investigated in this study.The adsorption isotherms,kinetics and thermodynamics werestudied to explore adsorption characteristics and mechanisms.The results showed that heavy metals played a dominantrole in controlling the competitive adsorption with p-NP in a sequence of Cu2+>Cd2+>Zn2+.The equilibrium data foradsorption of p-NP by WBFS could be well described by Freundlich isotherm model,while Langmuir isotherm couldbetter fit the data for the adsorption of heavy metal ions on WBFS.The adsorption energy of p-NP calculated by D-Rmodel in each system was-7.53,-7.07,-7.96and-7.86kJ/mol,respectively.The results showed that WBFS adsorbedp-NP via physical adsorption,while adsorbed metal ions via chemical adsorption and ion exchange.The kinetic resultsdemonstrated that the adsorption rate of p-NP decreased in the presence of heavy metal ions.And the corresponding timeto reach adsorption equilibrium was prolonged.However,the patterns for the adsorption of heavy metal ions were notsignificantly influenced in the presence of p-NP.In the binary system,WBFS exhibited relative higher affinity andselectivity for Cu2+,Cd2+and Zn2+than p-NP.The adsorption data of p-NP and heavy metal ions were fitted well by thepseudo-second-order model in both single and binary systems.The values ofΔG decreased with increasing temperature,indicating the spontaneous nature for the adsorption of p-NP and Cu2+、Cd2+、Zn2+was proportional to the temperature.The thermodynamics results also indicated the adsorption were an endothermic and entropy-increasing process.

关 键 词：高炉水淬渣 对硝基苯酚 重金属 等温线 热力学 动力学 竞争吸附 

分 类 号：X753[环境科学与工程—环境工程]