活性炭/铁氧化物磁性复合吸附材料的制备及去除水中酸性橙Ⅱ的研究

Magnetic adsorbents: activated carbon/iron oxide composites for AO7 removal from aqueous system

为获得同时具有优良的吸附特性和磁分离性的吸附材料,把活性炭和铁氧化物进行复合,得到活性炭/铁氧化物磁性复合吸附材料.吸附饱和后,用简单的磁分离工序即可把该吸附材料从溶液中快速分离出来.用共沉淀法制备了活性炭与铁氧化物质量比分别为3∶2和3∶1的磁性复合吸附材料,并用磁强计、BET比表面测定仪、XRD和扫描电镜对其进行了表征.考察了制备温度对复合吸附材料磁性的影响,研究了磁性复合材料吸附去除水中偶氮染料酸性橙Ⅱ的动力学、等温线及pH的影响.结果表明,不同温度条件下制备的复合吸附材料均有良好的磁性能,铁氧化物的存在对其比表面或者孔结构影响不大;活性炭铁氧化物磁性复合吸附材料对偶氮染料酸性橙Ⅱ的吸附动力学和吸附等温线也表明铁氧化的存在对活性炭的高吸附能力没有影响.

The magnetic properties of iron oxides and the adsorption features of activated carbon were combined in a composite to produce magnetic adsorbents. This composite could be used as adsorbent for contaminants in aqueous system and subsequently removed from the water by a simple magnetic procedure. Using chemical co-precipitation, activated carbon/iron oxide magnetic composite was prepared with weight rations of 3 ： 1 and 3：2 and characterized by magnetization measurements, BET surface areas measurements, powder XRD and SEM. The results suggested that the main magnetic phase presented was maghemite and the presence of iron oxide did not significantly affect the surface area or pore structure of activated carbon. The composites prepared at different temperature varying from room temperature to 70℃ all had good magnetism and could be well separated from aquatic system by a magnet. In addition, the adsorption kinetics and adsorption isotherm of AO7 onto the composites also showed that the presence of iron oxide did not affect the adsorption capacity of the activated carbon.