Efficient Approach for Cd2+ and Ni2+ Removal and Recovery Using Mesoporous Adsorbent with Tunable Selectivity

详细信息    查看全文

• 作者：Koon Fung Lam ; King LunYeung ; Gordon McKay
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：May 1, 2007
• 年：2007
• 卷：41
• 期：9
• 页码：3329 - 3334
• 全文大小：211K
• 年卷期：v.41,no.9(May 1, 2007)
• ISSN：1520-5851

文摘

Cadmium pollution from the manufacture and disposal ofNiCd batteries remains an important problem in developingcountries. Among the available remedial technologies,adsorption is popular because of its low cost and simplicity.The mesoporous NH₂-MCM-41 displays good adsorptioncapacities for cadmium and nickel ions. This workdemonstrated for the first time the use of the competitionbetween complexant and sorbent to create high adsorptionselectivity. The selectivity was manipulated by the judicioususe of a chelating agent, thus achieving on-demand100% selectivity for either Cd²⁺ or Ni²⁺ adsorption. Singleand binary components adsorption studies, carried outwith different metals and EDTA concentrations, solutioncompositions and pH, showed that NH₂-MCM-41 adsorbsonly cadmium with a capacity of 0.56 mmol g^-1 frombinary mixtures at [EDTA]/[M²⁺] = 0.5 and pH 5. TheNH₂-MCM-41 displays 100% selectivity for nickel adsorptionat [EDTA]/[M²⁺] = 0.5 and pH 2 with a measured adsorptioncapacity of 0.50 mmol g^-1. Pure Cd²⁺ and Ni²⁺ solutionswere recovered by a simple acid wash, and the regeneratedadsorbent could be reused without lost of performance(i.e., adsorption capacity and selectivity).