摘要
含铬废水的直接排放会对自然环境造成严重危害.为探究零价铁-生物炭材料(Fe^(0)-BC)与Cr(Ⅵ)的反应效能,以木质垃圾与印染行业废铁泥两种亟需处理的固体废物作为原料,在不同温度下通过碳热还原制备Fe^(0)-BC,并将其应用于水中Cr(Ⅵ)的去除.材料表征结果表明,1200℃下制备的Fe^(0)-BC材料(Fe^(0)-BC-1200)性能最佳,其比表面积为105.6 m^(3)/g,孔径为6.23 nm,物相主要由Fe^(0)、Cu^(0)、C以及少量杂质构成,其中Fe^(0)以球状的颗粒形式分散附着在碳的孔结构中,且大小均匀,粒度基本达到纳米级.通过静态试验考察了Fe^(0)-BC材料对Cr(Ⅵ)的去除过程,发现Fe^(0)-BC-1200对Cr(Ⅵ)的去除效果最好,在初始浓度为20 mg/L、初始pH为3.5、投加量为2.5 g/L的条件下,Cr(Ⅵ)的去除率达到95.2%.Cr(Ⅵ)的去除过程符合准二级反应动力学过程和Langmuir等温吸附模型(R2>0.99),最大吸附量为10.71 mg/g.Cr(Ⅵ)的去除是包含吸附、还原以及络合沉淀等共同作用的结果,此外,Cu^(0)的存在有利于催化Fe^(0)的氧化,从而促进Cr(Ⅵ)的去除.研究显示,利用固体废物制备的Fe^(0)-BC材料成本低且对于含Cr(Ⅵ)废水的解毒效果显著,是实现“以废治废”的环境治理新思路.
If chromium containing wastewater is directly discharged,it will cause serious harm to the natural environment.In order to explore the reaction efficiency of zero-valent iron/biochar(Fe^(0)-BC)and Cr(Ⅵ),the Fe^(0)-BC was synthesized by the carbothermal reduction of wood waste and printing and dyeing industry iron sludge at different temperatures and applied to remove Cr(Ⅵ)in water.The characteristics of Fe^(0)-BC were determined by specific surface area analyzer and scanning electron microscope(SEM),and the results showed that the Fe^(0)-BC-1200 prepared at 1200℃had the best performance,with a specific surface area of 105.6 m^(3)/g and a pore diameter of 6.23 nm.The Fe^(0)-BC-1200 was mainly composed of Fe^(0),Cu^(0),C and a small amount of impurities.Fe^(0) particles were dispersed and attached in the pore structure of carbon as spherical particles with uniform size distribution at the nanometer level.Furthermore,the removal process of Cr(Ⅵ)by Fe^(0)-BC was studied through batch experiments.The Fe^(0)-BC-1200 showed the best removal performance,and the removal rate of Cr(Ⅵ)could reach 95.2%under the conditions of initial concentration of 20 mg/L,initial pH value of 3.5 and dosage of 2.5 g/L.The removal process of Cr(Ⅵ)was well predicted by the pseudo-second-order model and Langmuir equation(R2>0.99),and the maximum adsorption capacity was 10.71 mg/g.The removal mechanisms mainly included adsorption,reduction and complex precipitation.In addition,the presence of Cu^(0) was beneficial to catalyze the oxidation of iron,thus promoting the removal of Cr(Ⅵ).The Fe^(0)-BC prepared with solid waste has the advantages of low cost and significant detoxification effect on Cr(Ⅵ)-containing wastewater,which is a new idea to realize the purpose of‘dealing pollution with waste’.
作者
陈超
刘建国
赵光琪
刘美佳
李丽
CHEN Chao;LIU Jianguo;ZHAO Guangqi;LIU Meijia;LI Li(Research Institute of Solid Waste Management,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;School of Environment,Tsinghua University,Beijing 100084,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2023年第5期995-1005,共11页
Research of Environmental Sciences
基金
国家重点研发计划项目(No.2018YFC1902906,2019YFC1906900)。
