碳纳米管作为新型碳材料,具有独特的一维管状的微结构特性,使它具有优异的吸附性能,近几年受到研究者的高度重视。文章采用催化裂解法制备多壁碳纳米管,先经空气纯化,再以浓硝酸-浓硫酸氧化,将其用于处理水中难降解多氯代有机物-五氯苯酚。经透射电镜和比表面积分析表明,碳纳米管纯度高,孔隙均匀,内径为30nm左右,比表面积为150m2/g。考察碳纳米管对五氯苯酚的吸附性能和主要影响因素结果表明:碳纳米管对五氯苯酚吸附平衡时间为1h,是活性炭的1/10,吸附速率常数为0.0994min-1;吸附等温线符合Freundlich型;随着温度的升高,碳纳米管对五氯苯酚的吸附量减小;pH在4~10时随pH增加碳纳米管对五氯苯酚的吸附降低,pH大于10之后又上升,存在最低吸附量的pH值。
Carbon nanotubes,with many special properties,have received increasing attention in recent years for application as adsorbent. Characteristics and primary factors affecting adsorption of pentachlorophenol (PCP) on multiwalled carbon nanotubes (MWCNTs)with preparation by catalytic splitting decomposition were studied. MWCNTs were characterized by transmission electron microscopy (TEM)and BET surface area. After purification and oxidation by air and HNO3-H2SO4,MWCNTs exhibited very clean,with diameter and surface area of MWCNTs 30nm and 150m2/g respectively. Results showed that the adsorption equilibrium time of PCP on MWCNTs and activated carbon were 1h and 10h respectively and adsorption rate constant was 0.0994min-1,with PCP in aqueous solution in accordance with Freundlich. The effects of primary factors of temperature and pH on adsorption were also investigated.