摘要
本文利用褐铁矿中针铁矿经热脱水相变获得以纳米晶赤铁矿为主要物相的纳米-微米多级孔结构材料,并用于模拟净化富Mn^(2+)地下水。同时考察了热处理温度、初始pH值、初始Mn^(2+)浓度、吸附反应时间等对材料去除溶液中Mn^(2+)的影响。XRD、TEM、BET表征结果表明,300℃热处理产物中赤铁矿孔径最小为2.7 nm,比表面积最大达到107.4 m^2/g。吸附实验结果表明,在pH值5~10的范围内,p H值对煅烧褐铁矿颗粒对Mn^(2+)去除效果影响较小;材料在贫氧条件下对水中低浓度Mn^(2+)的最大吸附量为6.45 mg/g;吸附动力学符合准二级动力学模型;褐铁矿热处理形成的纳米晶赤铁矿对Mn^(2+)具有吸附和催化氧化作用,其中的杂质锰氧化物对Mn^(2+)的吸附和催化氧化具有增强作用。
Nano-hematite with multi-porous texture was prepared from the transformation of limonite by thermal treatment. The prepared nano-hematite was utilized to remove Mn2＋from aqueous solution. The effect of heat treatment temperature, initial pH, Mn2＋concentration and contact time on removal of Mn2＋was investigated. The results of characterizations（ XRD, TEM, BET） showed that the hematite exhibited the smallest pore size of 2. 7 nm and the largest surface area of 107. 4 m^2/g after thermal treatment at 300℃. The results of batch experiments indicated that the effect of pH varying from 5 to 10 on the removal of Mn2＋was marginal and could almost be ignored.The maximum adsorption capacity of the thermally treated limonite to Mn2＋reached 6. 45 mg/g. The kinetics results showed that the adsorption of Mn2＋by nano-hematite followed pseudo second-order kinetic model. The prepared nano-hematite presented excellent adsorption performance and catalytic oxidation to Mn2＋. Furthermore, the existence of manganese oxide promoted the adsorption performance and dramatically improved the role of catalytic oxidation in removal of Mn2＋from aqueous solution.
作者
张羽
刘海波
陈平
皮汇钰
陈天虎
ZHANG Yu;LIU Hai-bo;CHEN Ping;PI Hui-yu;CHEN Tian-hu(Laboratory of Nano-mineral and Environmental Materials,School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,Chin)
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2018年第4期687-696,共10页
Acta Petrologica et Mineralogica
基金
国家自然科学基金资助项目(41572029,41402030).
关键词
褐铁矿
赤铁矿
纳米孔
除锰
催化氧化
limonite
hematite
nanopore
removal of Mn2 ＋
catalytic oxidation
