Competitive adsorption of Pb²⁺, Cu²⁺ and Cd²⁺ ions from aqueous solutions by multiwalled carbon nanotubes

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• 作者：Li ; Yan-Hui ; Ding ; Jun ; Luan ; Zhaokun ; Di ; Zechao ; Zhu ; Yuefeng ; Xu ; Cailu ; Wu ; Dehai ; Wei ; Bingqing
• 关键词：A. Carbon nanotubes ; B. Oxidation ; C. Adsorption ; D. Functional groups
• 刊名：Carbon
• 出版年：2003
• 出版时间：2003
• 年：2003
• 卷：41
• 期：14
• 页码：2787-2792
• 全文大小：112 K

文摘

The individual and competitive adsorption capacities of Pb²⁺, Cu²⁺ and Cd²⁺ by nitric acid treated multiwalled carbon nanotubes (CNTs) were studied. The maximum sorption capacities calculated by applying the Langmuir equation to single ion adsorption isotherms were 97.08 mg/g for Pb²⁺, 24.49 mg/g for Cu²⁺ and 10.86 mg/g for Cd²⁺ at an equilibrium concentration of 10 mg/l. The competitive adsorption studies showed that the affinity order of three metal ions adsorbed by CNTs is Pb²⁺>Cu²⁺>Cd²⁺. The Langmuir adsorption model can represent experimental data of Pb²⁺ and Cu²⁺ well, but does not provide a good fit for Cd²⁺ adsorption data. The effects of solution pH, ionic strength and CNT dosage on the competitive adsorption of Pb²⁺, Cu²⁺ and Cd²⁺ ions were investigated. The comparison of CNTs with other adsorbents suggests that CNTs have great potential applications in environmental protection regardless of their higher cost at present.