Mutual Effects of Pb(II) and Humic Acid Adsorption on Multiwalled Carbon Nanotubes/Polyacrylamide Composites from Aqueous Solutions
Mutual Effects of Pb(II) and Humic Acid Adsorption on Multiwalled Carbon Nanotubes/Polyacrylamide Composites from Aqueous Solutions
复制标题
水溶液中多壁碳纳米管/聚丙烯酰胺复合材料 Pb(II) 和腐植酸吸附的相互作用
DOI：
10.1021/es104047d
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发表时间：
2011-04-15
影响因子：
11.4
通讯作者：
Wang, Xiangke
中科院分区：
文献类型：
--
作者：
Yang, Shubin;Hu, Jun;Wang, Xiangke
本文研究了用n -2等离子体诱导接枝技术制备的聚丙烯酰胺（PAAM）接枝多壁碳纳米管（MWCNTs/PAAM）对Pb（II）和天然有机大分子化合物（腐植酸，HA）的吸附。考察了HA/Pb（II）对Pb（II）和HA在MWCNTs/PAAM上吸附的相互作用，以及pH、离子强度、HA/Pb（II）浓度和HA/Pb（II）加成顺序的影响。结果表明，Pb（II）和HA的吸附与pH和离子强度密切相关。HA的存在导致低pH下对Pb（II）的吸附明显增加，高pH下对Pb（II）的吸附明显减少，而Pb（II）的存在导致对HA的吸附增加。吸附的HA有助于改变吸附剂的表面性质，并使Pb（II）与吸附的HA部分络合。HA/Pb（II）浓度和添加顺序对Pb（II）和HA吸附的影响不同，表明不同的吸附机制。HA在MWCNTs/PAAM上吸附后，在pH 5.0时对Pb（II）的吸附能力增强；MWCNTs/PAAM吸附Pb（II）后，对HA的吸附能力也有所增强。这些结果对于估计和优化MWCNT/PAAM复合材料对金属离子和有机物的去除具有重要意义。
This paper examines the adsorption of Pb(II) and a natural organic macromolecular compound (humic acid, HA) on polyacrylamide (PAAM) -grafted multiwalled carbon nanotubes (denoted as MWCNTs/PAAM), prepared by an N-2-plasma-induced grafting technique. The mutual effects of HA/Pb(II) on Pb(II) and HA adsorption on MWCNTs/PAAM, as well as the effects of pH, ionic strength, HA/Pb(II) concentrations, and the addition sequences of HA/Pb(II) were investigated. The results indicated that Pb(II) and HA adsorption were strongly dependent on pH and ionic strength. The presence of HA led to a strong increase in Pb(II) adsorption at low pH and a decrease at high pH, whereas the presence of Pb(II) led to an increase in HA adsorption. The adsorbed HA contributed to modification of adsorbent surface properties and partial complexation of Pb(II) with the adsorbed HA. Different effects of HA/Pb(II) concentrations and addition sequences on Pb(II) and HA adsorption were observed, indicating different adsorption mechanisms. After adsorption of HA on MWCNTs/PAAM, the adsorption capacity for Pb(II) was enhanced at pH 5.0; the adsorption capacity for HA was also enhanced after Pb(II) adsorption on MWCNTs/PAAM. These results are important for estimating and optimizing the removal of metal ions and organic substances by use of MWCNT/PAAM composites.