连铸铁泥制备纳米α-Fe_(2)O_(3)及光催化去除Cr(Ⅵ)  

Photocatalytic removal of Cr(Ⅵ)fromα-Fe_(2)O_(3)nanoparticles prepared by continuous casting iron sludge

作　　者：赵泽坤 李素芹[1] 郭鹏辉 ZHAO Ze-kun;LI Su-qin;GUO Peng-hui(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083

出　　处：《连铸》2022年第5期30-36,共7页Continuous Casting

摘　　要：连铸铁泥富含铁元素,资源化利用是必然选择。以连铸铁泥为原料,采用水热法成功制备纳米α-Fe_(2)O_(3),实现高附加值利用。研究结果显示,所制备的纳米α-Fe_(2)O_(3)为均匀的球状介孔结构,比表面积为48.78 m^(2)/g,平均晶粒尺寸约40~50 nm,较大的比表面积与较小的晶粒尺寸可提供大量的光催化活性位点,有利于提升材料的光催化性能。将纳米α-Fe_(2)O_(3)应用于Cr(Ⅵ)脱除的光催化剂,显示较好的Cr(Ⅵ)废水脱除效果,180 min内去除率可达100%。经过5次循环后,Cr(Ⅵ)的去除效率仍可达到89.2%,说明纳米α-Fe_(2)O_(3)具有良好的可重复使用性。对光催化去除Cr(Ⅵ)的反应机理进行研究,表明光生电子(e^(-))、羟基自由基(·OH)和超氧阴离子(·O_(2)^(-))是参与Cr(Ⅵ)去除的主要活性物质。本研究可将工业副产品连铸铁泥转化为高附加值的纳米材料,并为重金属废水脱除提供了一个新的思路,有较高的实际应用价值。Continuous cast iron mud is rich in iron,so resource utilization is an inevitable choice.In this paper,we successfully preparedα-Fe_(2)O_(3)nanoparticles from continuous casting iron sludge by hydrothermal method and realized high value-added utilization.The preparedα-Fe_(2)O_(3)nanoparticles were polymerized into uniform spherical mesoporous structure with a specific surface area of 48.78 m^(2)/g and the average grain size was about 40-50 nm.Large specific surface area and small grain size provided a large number of photocatalytic active sites,which was conducive to improving the photocatalytic performance of the material.Therefore,theα-Fe_(2)O_(3)nanoparticles has a good removal rate of Cr(Ⅵ)polluted wastewater,and the removal rate can reach 100%within 180 min.In addition,after 5 cycles,the removal efficiency of Cr(Ⅵ)can still reach 89.2%,indicating thatα-Fe_(2)O_(3)nanoparticles has good reusability.The mechanism of photocatalytic removal of Cr(Ⅵ)was studied.Photogenerated electron(e^(-)),hydroxyl radical(·OH)and superoxide anion(·O_(2)^(-))are the main active substances involved in the removal of Cr(Ⅵ).Therefore,this study can transform the industrial by-product of continuous cast iron sludge into high value-added nanomaterials,and provides a new idea for the removal of heavy metal wastewater,which has high practical application value.

关 键 词：钢铁冶金 连铸铁泥 纳米α-Fe_(2)O_(3) 重金属处理 光催化 

分 类 号：O643.36[理学—物理化学] O644.1[理学—化学] X703[环境科学与工程—环境工程]