Effect of humic acid on the sulfamethazine adsorption by functionalized multi-walled carbon nanotubes in aqueous solution: mechanistic study
Effect of humic acid on the sulfamethazine adsorption by functionalized multi-walled carbon nanotubes in aqueous solution: mechanistic study
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DOI：
10.1039/c5ra26913j
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发表时间：
2016-02
期刊：
影响因子：
3.9
通讯作者：
Quanquan Yang;Xiaogan Li;Guangcai Chen;Jian-feng Zhang;B. Xing
中科院分区：
文献类型：
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作者：
Quanquan Yang;Xiaogan Li;Guangcai Chen;Jian-feng Zhang;B. Xing
研究了3种多壁碳纳米管（MWCNTs）对腐殖酸（HA）的吸附及其对磺胺二甲嘧啶（SMZ）吸附的影响。HA和SMZ的吸附等温线均符合Langmuir模型（R2 > 0.99）。HA在MWCNTs上的吸附量随pH值的降低和离子强度的增加而增加，随MWCNTs表面氧含量的增加而减少，表明静电和疏水相互作用是HA在MWCNTs上的主要吸附机制。HA的存在抑制SMZ吸附到多壁碳纳米管通过竞争相互作用，分子筛，和孔堵塞。吸附在MWCNTs表面的HA也改变了SMZ和MWCNTs之间的静电和疏水相互作用，减少SMZ的吸附。显微傅里叶变换红外光谱分析结果表明，MWCNTs与SMZ和HA之间以及SMZ与HA之间的π-π和氢键作用在吸附过程中也起着重要作用。目前的研究结果有助于评估多壁碳纳米管在抗生素去除或分析中的潜在利用。
Adsorption of humic acid (HA) and its effect on sulfamethazine (SMZ) adsorption by three types of multi-walled carbon nanotubes (MWCNTs) were investigated. The adsorption isotherms of HA and SMZ were well depicted by the Langmuir model (R2 > 0.99). HA adsorption onto MWCNTs increased as pH decreased and ionic strength increased, and decreased with increasing surface oxygen content of MWCNTs, implying that electrostatic and hydrophobic interactions were the main adsorption mechanisms. The presence of HA inhibited SMZ adsorption onto MWCNTs via competitive interactions, molecular sieving, and pore blockage. HA adsorbed on the MWCNTs surfaces also altered the electrostatic and hydrophobic interactions between SMZ and MWCNTs, decreasing the adsorption of SMZ. The results of micro-Fourier transform infrared spectroscopy suggested that π–π and hydrogen-bonding interactions of MWCNTs with SMZ and HA, and/or between SMZ and HA also play an important role in the adsorption process. The current findings shed light on evaluating the potential utilization of MWCNTs in antibiotics removal or analysis.