高比表面积介孔网状氧化镁的制备、表征及对废水中Pb(Ⅱ)的吸附性能和机理  

Mesoporous Reticular Magnesium Oxide with High Specific Surface Area:Preparation, Characterization, Adsorption Performance and Mechanism for Pb(Ⅱ) in Wastewater

作　　者：黄建翠 凌观爽 武艳妮 翟俊 宗俊 HUANG Jian-Cui;LING Guan-Shuang;WU Yan-Ni;ZHAI Jun;ZONG Jun(School of Chemistry and Molecular Engineering,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学化学与分子工程学院,上海200241

出　　处：《无机化学学报》2020年第11期2031-2040,共10页Chinese Journal of Inorganic Chemistry

摘　　要：以天然水菱镁矿为原料,通过"煅烧-水化-煅烧"的简单方法制备了高比表面积介孔网状MgO,且实验过程中无须加入任何试剂。系统性研究了氧化镁用量、吸附时间、吸附温度及pH对氧化镁吸附模拟废水中铅离子吸附性能的影响,揭示了吸附机理,并考察了氧化镁对多种离子的吸附效果。结果表明:该氧化镁吸附剂具有188 m2·g-1的高比表面积和0.85 cm3·g-1的高孔体积,平均孔径为12.33 nm,其吸附动力学和等温线数据与伪二级模型和Langmuir模型高度吻合,表明重金属离子在氧化镁上为单层化学吸附。MgO介孔网状结构表现出对Pb(Ⅱ)的高吸附性能,最大吸附量为7 431.5 mg·g-1,该数值远高于其他报道的基于MgO吸附剂的数值,铅去除率高达99.8%以上。介孔网状MgO的吸附机理主要是羟基官能团以及Mg(Ⅱ)与MgO表面重金属离子之间的离子交换所致。另外,该氧化镁可同时吸附多种离子,对Cd、Cr、Ni、As、Co、P、Se、Be、Bi、Cu、Fe、Mn、V、Zn、Al离子均具有优异的吸附性能。Using natural hydromagnesite as raw material, mesoporous reticular MgO with high specific surface areawas prepared by the simple method of"calcination-hydration-calcination", and no reagent was added in the experi-mental process.The effects of MgO dosage, adsorption time, adsorption temperature and pH on the adsorption oflead ions in simulated wastewater by MgO were systematically studied, the adsorption mechanism was revealed, andthe adsorption effect of MgO on various ions was investigated.The results showed that the MgO adsorbent had ahigh specific surface area of 188 m2·g-1 and a high pore volume of 0.85 cm3·g-1, with an average pore diameter of 12.33 nm.The adsorption kinetics and isotherm data are highly consistent with the pseudo-second-order model andLangmuir model, indicating the monolayer chemisorption of heavy metal ions.MgO mesoporous reticular structureexhibited high adsorption performance for Pb(Ⅱ), and the maximum adsorption capacity was up to 7 431.5 mg·g-1,which was far higher than other reported values based on MgO adsorbent, and the removal rate of Pb(Ⅱ) was over 99.8%.The adsorption mechanism is mainly due to hydroxyl functional groups and ion exchange between Mg andheavy metal ions on MgO surface.In addition, the MgO can adsorb various ions simultaneously, and has excellentadsorption performance on Cd, Cr, Ni, As, Co, P, Se, Be, Bi, Cu, Fe, Mn, V, Zn and Al ions.

关 键 词：水菱镁矿 介孔网状 高比表面积 氧化镁 铅离子 吸附 

分 类 号：TQ132.2[化学工程—无机化工]