研究报告
张晓蕾,陈静,韩京龙,张高生.壳-核结构Fe3O4/MnO2磁性吸附剂的制备、表征及铅吸附去除研究[J].环境科学学报,2013,33(10):2730-2736
壳-核结构Fe3O4/MnO2磁性吸附剂的制备、表征及铅吸附去除研究
- Preparation and evaluation of shell-core structured Fe3O4/MnO2 magnetic adsorbent for Pb(Ⅱ) removal from aqueous solutions
- 关键词：壳-核结构 Fe3O4/MnO2 磁性吸附剂 铅 吸附
- 基金项目：国家自然科学基金项目(No.51178453);烟台市科技发展计划(No.2012132)
- 作者
- 单位
- 张晓蕾
- 烟台大学环境与材料工程学院, 烟台 264003
- 陈静
- 中国科学院烟台海岸带研究所, 中国科学院海岸带环境过程重点实验室, 山东省海岸带环境过程重点实验室, 烟台 264003
- 韩京龙
- 烟台大学环境与材料工程学院, 烟台 264003
- 张高生
- 中国科学院烟台海岸带研究所, 中国科学院海岸带环境过程重点实验室, 山东省海岸带环境过程重点实验室, 烟台 264003
- 摘要：采用共沉淀法制备了具有壳-核结构的磁性吸附剂Fe3O4/MnO2,对其性质进行了系统表征,并对其铅吸附行为进行了初步研究.透射电镜(TEM)结果表明,Fe3O4/MnO2为大小不规则的纳米级细小颗粒.X-射线衍射仪(XRD)表征结果表明,Fe3O4/MnO2具有尖晶石的结构.振动样品磁强计(VSM)测得比饱和磁化强度为54.7 A·m2·kg-1, 吸附剂磁性较强,易于磁分离;BET比表面积为76.5 m2·g-1.吸附试验结果表明,Fe3O4/MnO2对铅具有良好的去除效果(特别是在低平衡浓度情况下),最大吸附量为142.0 mg·g-1(pH=5.0);Langmuir等温线能更好地拟合Fe3O4/MnO2对溶液中铅的吸附(R2=0.852);吸附速率较快,在初始30 min内可达到平衡吸附量的80%,准二级动力学模型(R2=0.959)能较好地描述吸附过程;溶液pH对Fe3O4/MnO2吸附铅的影响较为明显,随pH升高,吸附量增大,但离子强度变化对吸附影响不大.
- Abstract：An adsorbent with Fe3O4 as magnetic core and MnO2 as shell was prepared by co-precipitation process. The adsorbent was characterized using multiple techniques and its performance for Pb(Ⅱ) removal from aqueous solution was investigated. The TEM image indicated that the shape of nanosized Fe3O4/MnO2 particles was irregular. X-ray powder diffraction (XRD) analysis showed that the magnetic phase in Fe3O4/MnO2 was spinel magnetite. The adsorbent has a highly specific saturation magnetization of 54.7 A·m2·kg-1 and a specific surface area of 76.5 m2·g-1. The results of batch sorption experiments suggested that the Fe3O4/MnO2 magnetic adsorbent was effective for Pb(Ⅱ) removal from water, particularly at low equilibrium concentration. The isotherm data was well fitted by Langmuir model (R2=0.852) with a maximal Pb adsorption capacity of 142.0 mg·g-1 at pH 5.0. The adsorption of Pb(Ⅱ) was very fast and over 80% of the equilibrium sorption capacity was achieved within 30 min. The pseudo-second order model (R2=0.959) was more suitable to describe adsorption kinetic data. The Pb(Ⅱ) adsorption increased with increasing values of solution pH and was not significantly affected by the change of ionic strength.
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