聚合氯化铝微波法修饰磁性碳纳米管对水中腐殖酸的去除

用化学共沉淀法制备磁性碳纳米管,然后以聚合氯化铝(PAC)通过微波法修饰得到磁性聚合氯化铝碳纳米管复合材料,并用以去除水中的腐殖酸(HA),对复合材料的组成与结构进行了表征,考察了不同微波制备条件下复合材料去除HA的效果,研究了吸附工艺中HA去除的影响因素,对复合材料同步去除HA和浊度的可行性进行了探讨。能谱、X-射线衍射及红外光谱分析表明,PAC和磁性物质Fe3O4、γ-Fe2O3成功负载于碳纳米管上。PAC修饰显著提高了磁性碳纳米管对HA的去除率。在微波功率600 W及微波时间6 min条件下得到的复合材料去除HA的效果最佳,去除率达99.15%。当HA初始质量浓度小于25 mg/L时,HA去除率较高,但高于25 mg/L后吸附量变化不大而去除率下降;HA去除率随材料投加量增大而增大,但大于0.5 g/L后基本不变;在酸性与中性条件下HA去除率较高,在碱性条件下急剧下降;对于初始质量浓度为20 mg/L的HA溶液,吸附前5 min的HA去除速率很快,90 min时达到吸附平衡,平衡吸附量为39.48 mg/g;温度对去除HA没有影响。控制适当的条件,可同步去除HA和浊度,去除率同步达95%以上。

Removing humic acid by using the magnetic carbon nanotubes microwave-decorated with the polyaluminum chloride

The article intends to investigate the composition and characteristic features of the new material known as the magnetic carbon nanotubes decorated with polyaluminium chloride (PAC-MWCNTs) for the HA removal,the factors involving the effect of HA removal,the possibility in removing HA and turbidity simultaneously,along with a discussion of the microwave conditions.The so-called magnetic PAC-MWCNTs is by chemical co-precipitation method to obtain the magnetic carbon nanotubes composites decorated with PAC by the microwave method,which are used to remove the humic acid (HA) from the aqueous solution.Careful analysis of the energy disperse spectroscopy (EDS),the X-ray diffraction (XRD) and Fourier transform infrared (FTIR) indicates that,besides containing carbon nanotubes,the material also enjoys the PAC and magnetic substances,such as Fe3O4 and γ-Fe2O3.At the same time,we have also found that the removal rate of HA by the carbon nanotubes can be significantly increased by adding PAC and magnetic materials to itself.The product radiated under 600 W of the microwave power for 6 min can increase its best removing rate of humic acid at an efficient rate of 99.15％.What is more,the said HA removal rate can be made even greater on the condition that the initial concentration of HA solution would be lower than 25 mg/L.Nevertheless,if the initial concentration of HA solution is over 25 mg/L,even little change of the adsorptive capacity might also lead to the drop of the removal rate.Besides,the HA removal rate can also be made to increase with the dosage of the magnetic PAC-MWCNTs,though it may seem to be basically unchanged when the dosage remains o.ver 0.5 g/L.Since under the acidic and neutral condition the HA removal rate can be promoted more quickly whereas the rate can also be made to drop with the rising of the pH value under the alkaline condition.On the other hand,even if the initial concentration of HA is 20 mg/L,its removal speed can be sped up for the first 5 min and the adsorption capacity is 39.48 mg/g in 90 min.Nonetheless,the reaction temperature can hardly have any effect on the HA removal rate.What is more,it is also possible for the magnetic carbon nanotubes coated with PAC to achieve a better effect on the removal of HA and the turbidity efficiently at about 95％ if it is possible somehow to control the stirring conditions and time.Thus,it can be seen that the magnetic carbon nanotubes coated PAC can be made into a kind of adsorbent of great prospect to remove HA and turbidity in the drinking water.