Peng Xianjia, Luan Zhaokun, Zhang Hongmei
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Chemosphere. 2006 Apr;63(2):300-6. doi: 10.1016/j.chemosphere.2005.07.019. Epub 2005 Oct 5.
In this work, the adsorption features of montmorillonite and the magnetic properties of Cu(II)/Fe(III) oxides were combined in a material to produce magnetic adsorbent, which can be separated from the medium by a simple magnetic process after adsorption. The magnetic material is effective for the removal of humic acid. At pH 6.1, 96% removal was observed from 4.4 mg l(-1) humic acid solution containing 0.02 M NaCl. The adsorption is pH and ionic strength dependent. Adsorption is favored at lower pH values and dissolved NaCl can enhance the adsorption. The adsorption mechanism of humic acid to the magnetic material was suggested to be the ligand exchange reaction between carboxylic groups of humic acid molecules and the magnetic material surface. The magnetic material can be thermally regenerated. The temperature and time required to achieve good regeneration efficiency were determined to be 300 degrees C and 3 h, respectively. The regenerated adsorbent is still magnetic and approximately has as high specific saturation magnetization and good adsorption capacities as the as-prepared adsorbent.
在本研究中，将蒙脱石的吸附特性与Cu(II)/Fe(III)氧化物的磁性相结合，制备出一种磁性吸附剂，吸附后可通过简单的磁分离过程从介质中分离出来。该磁性材料对腐殖酸的去除效果良好。在pH 6.1时，从含有0.02 M NaCl的4.4 mg l(-1)腐殖酸溶液中观察到96%的去除率。吸附作用取决于pH值和离子强度。在较低的pH值下吸附效果较好，溶解的NaCl可以增强吸附作用。腐殖酸对磁性材料的吸附机制被认为是腐殖酸分子的羧基与磁性材料表面之间的配体交换反应。该磁性材料可以进行热再生。经测定，实现良好再生效率所需的温度和时间分别为300℃和3小时。再生后的吸附剂仍具有磁性，其比饱和磁化强度和吸附容量与制备的吸附剂相近。
