期刊
ANALYTICA CHIMICA ACTA
卷 432, 期 2, 页码 201-211出版社
ELSEVIER
DOI: 10.1016/S0003-2670(00)01372-6
关键词
adsorption; silica gel; 2,4-dichlorophenoxyacetic acid
The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), chemically anchored on a silica gel surface, has been used for Cu(II), Ni(II), Zn(II) and Cd(II) adsorption from aqueous and ethanolic solutions at room temperature. The series of adsorption isotherms were adjusted to a modified Langmuir equation from data obtained by suspending the solid with MCl2 solutions (M = Cu, Ni, Zn and Cd), which gave the maximum number of moles adsorbed as 0.44, 0.32, 0.27 and 0.14 mmol g-l in water and 0.75, 0.52, 0.47 and 0.38 mmol g(-1) in ethanol for Cu, Ni, Zn, Cd, respectively. The retention of cations from aqueous solution was null at pH less than or equal to 3, however, the adsorption increased above this value up to pH 7. The maximum retention capacity followed the sequence Cu > Ni > Zn > Cd in both solvents and presented a non-linear correlation with enthalpy of hydration and also with charge/radius of each cation. The modified silica was applied for preconcentration and quantification of trace level metal ions present in water and ethanol samples. The immobilized surface was also used as a separation column for these four cations. Column resolution was determined fbr all cations as the ability of this surface to separate metal ions, determined as Rs(Cd-Zn) = 0.54, RSCd-Ni = 0.64, Rs(Cd-Cu) = 1.62, Rs(Zn-Ni) = 0.28, Rs(Zn-Cu) = 1.26 and Rs(Ni-Cu) = 0.68. (C) 2001 Elsevier Science B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据