冬凌草负载纳米零价铁吸附废水中的Pb^(2+)  

Adsorption of Pb^(2+)in Wastewater by Nanoscale Zero-valent Iron Supported by Rabdosia Rubescens

作　　者：左国强[1] 李晓乐[1] 张晓杰[1] 苏小莉[1] 张文生 ZUOGuo-qiang;LI Xiao-le;ZHANG Xiao-jie;SU Xiao-li;ZHANG Wen-sheng(Department of Metallurgy and Chemical Engineering,Jiyuan Vocational and Technical College,Jiyuan 459000,Henan,China)

机构地区：[1]济源职业技术学院冶金化工系,河南济源459000

出　　处：《有色金属（冶炼部分）》2022年第10期115-123,共9页Nonferrous Metals（Extractive Metallurgy)

基　　金：河南省2020年科技发展计划项目(202102210259);济源市2020年度科技发展计划项目(20022008)。

摘　　要：针对冶金行业产生的含铅废水导致的环境污染问题,以太行山脉盛产的野生冬凌草为载体,采用液相化学还原法制备了冬凌草负载纳米零价铁(RR-nZVI),并用于去除水中的Pb^(2+),详细考察了酸度、温度、RR-nZVI投加量、Pb^(2+)初始浓度和反应时间对Pb^(2+)去除率的影响。通过FTIR、XRD、SEM等手段对RR-nZVI去除Pb^(2+)的机理进行分析。结果表明,RR-nZVI投加量0.6 g/L、pH=5.0、Pb^(2+)初始浓度200 mg/L、室温下反应60 min时,Pb^(2+)的去除率达到了99.9%,吸附量达到394.7 mg/g。动力学试验表明,RR-nZVI对溶液中Pb^(2+)的吸附符合Lagergren准二级动力学模型,吸附过程主要受化学吸附控制。Langmuir模型能较好地描述RR-nZVI对Pb^(2+)的吸附过程,吸附以单层吸附为主。当Pb^(2+)的初始浓度小于10 mg/L时,滤液中的Fe浓度低于国家《铅、锌工业污染物排放标准(GB 25466—2010)》中规定的限量要求,不会对环境造成二次污染,为含Pb^(2+)废水的处理提供了一种有效的可供选择的材料。To address environmental pollution caused by wastewater containing lead produced in metallurgy industries, Rabdosia rubescens obtained from Taihang Mountains was used as carrier, Rabdosia rubescens loaded nano-zero-valent iron(RR-NZVI)was prepared by liquid phase chemical reduction method, and used to remove Pb^(2+)from water.Effects of pH value, temperature, RR-nZVI dosage, initial concentration of Pb^(2+)and reaction time on removal efficiency of Pb^(2+)were investigated.FTIR,SEM and XRD were used to characterize the mechanisms of Pb^(2+)removal.The results show that removal efficiency of Pb^(2+)is 99.9% and the maximum adsorption capacity of Pb^(2+)is 394.7 mg/g under the conditions including RR-nZVI dosage of 0.8 g/L,pH=5.0,initial concentration of Pb^(2+)of 200 mg/L,and reaction time of 60 min at room temperature.The results of kinetic experiments show that the adsorption kinetics of Pb^(2+)on RR-nZVI in solution is in accordance with Lagergren pseudo-second-order model, which is mainly controlled by chemical adsorption.The isothermal adsorption of Pb^(2+)on RR-nZVI could be well fitted with the Langmuir isothermal adsorption model, which suggested that the adsorption of Pb^(2+)from solution is mainly monolayer adsorption.When the initial Pb^(2+)concentration is less than 10 mg/L,Feconcentration in filtrate is lower than the limited demand of Emission Standard of Pollutants for Lead and Zinc Industry(GB 25466—2010),which would not cause secondary pollution to the environment.Consequently, it can provide an effective alternative material for treatment of wastewater containing Pb^(2+).

关 键 词：冬凌草 纳米零价铁 吸附 铅离子 

分 类 号：X703[环境科学与工程—环境工程] TQ085.412[化学工程]