改性多壁碳纳米管对水中Cd2+的去除

为了增加多壁碳纳米管(multiwall carbon nanotubers,MWNTs)对水中Cd2+的吸附量,使用混酸对多壁碳纳米管进行氧化处理,采用红外光谱进行结果表征,并探讨了吸附时间、pH值和MWNTs的使用量、Cd2+的浓度及干扰离子对镉离子吸附的影响。结果表明,吸附时间为1.5 h、pH为5.3、吸附效果最佳,随MWNTs量的增加Cd2+去除量增加,共存的阳离子会降低对Cd2+的吸附效果,对Cd2+的吸附符合Longmuir吸附定律。研究同时表明,pH小于2时Cd2+能容易从碳纳米管上解吸。初步探讨了Cd2+吸附机制。

Removal of Cd2+ from water by modified multiwall carbon nanotubers

In order to increase the adsorption amount of Cd2+ in water,the multiwall carbon nanotubers were treated by mixed acid,and the result was characterized by IR.The treated MWNTs were used to adsorb the Cd2+ in simulating water.The effect of adsorption time,pH,the amount of MWNTs,the concentration of Cd2+ and interfering ion on the adsorption of Cd2+ were discussed.The results indicated that optimal conditions of Cd2+ adsorption on treated MWNTs were time of 1.5 h and pH of 5.3.The amount of Cd2+ adsorption increased with increase of the amount of MWNTs,and effect of adsorption was depressed by existence of cation,the adsorption data fit the langmiur model and its linearized form well.Results of a desorption study showed that Cd2+ adsorbed onto MWCNTs could be easily desorbed at pH <2.The mechanism of Cd2+ adsorption was also discussed.