Acid-base behaviour and Cu2+ and Zn2+ complexation properties of the sepiolite/water interface

被引:55
作者
Vico, LI [1 ]
机构
[1] Univ Nacl Sur, Dept Quim, Cattedra Quim Gen & Inorgan, RA-8000 Bahia Blanca, Buenos Aires, Argentina
关键词
sepiolite; adsorption; copper; zinc;
D O I
10.1016/S0009-2541(03)00002-0
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Sepiolite is a clay mineral with a wide range of applications derived from its sorptive properties. In this work, aspects of the adsorption of Cu(II) and Zn(II) from aqueous solutions to particles of this material have been studied as a function of the pH and ionic strength of the medium. Cu2+, Zn2+, Mg2+ and Na+ in the suspensions were determined by atomic absorption spectrometry. Amounts of this cations interchanged had been calculated by the difference between concentrations before and after the contact with the mineral. The adsorption data suggest three possible mechanisms that could be involved in the interaction between metal ions like Cu2+ and the surface of the mineral: (1) A process of ion exchange in which Cu2+ replaces Na+. (2) Adsorption Of Cu2+ on surface squareSOH sites on the broken edges of the mineral with simultaneous release of protons. This mechanism takes into account the enhancement of adsorption with increasing pH. The final step of this reaction should be the incorporation of adsorbed cation to octahedral sheet. (3) Replacement of Mg2+ in the edges of octahedral sheet for Cu2+ could be another mechanism that contributes to the total adsorption phenomena. Similar mechanisms may involve the adsorption of Zn2+. The values obtained for complexation constants (constant capacitance model) were lower for this ion than for Cu2+. (C) 2003 Elsevier Science BY. All rights reserved.
引用
收藏
页码:213 / 222
页数:10
相关论文
共 24 条
[1]  
BAES CF, 1976, HYDROLYSIS CATIONS, P274
[2]   The four laws of soil chemistry: the Leeper lecture 1998 [J].
Barrow, NJ .
AUSTRALIAN JOURNAL OF SOIL RESEARCH, 1999, 37 (05) :787-829
[3]   REACTION-KINETICS OF THE ADSORPTION AND DESORPTION OF NICKEL, ZINC AND CADMIUM BY GOETHITE .1. ADSORPTION AND DIFFUSION OF METALS [J].
BRUEMMER, GW ;
GERTH, J ;
TILLER, KG .
JOURNAL OF SOIL SCIENCE, 1988, 39 (01) :37-52
[4]  
CARTER D. L., 1965, SOIL SCI, V100, P356, DOI 10.1097/00010694-196511000-00011
[5]   CATION ADSORPTION ON OXIDES AND CLAYS - THE ALUMINUM CASE [J].
CHARLET, L ;
SCHINDLER, PW ;
SPADINI, L ;
FURRER, G ;
ZYSSET, M .
AQUATIC SCIENCES, 1993, 55 (04) :291-303
[6]   KINETIC-STUDY OF THE ACIDIC INFLUENCE OF SEPIOLITE - MODIFICATIONS OF TEXTURAL PROPERTIES [J].
CORMA, A ;
MIFSUD, A ;
PEREZ, J .
CLAY MINERALS, 1986, 21 (01) :69-84
[7]   Th uptake on montmorillonite:: A powder and polarized extended X-ray absorption fine structure (EXAFS) study [J].
Dähn, R ;
Scheidegger, AM ;
Manceau, A ;
Curti, E ;
Baeyens, B ;
Bradbury, MH ;
Chateigner, D .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 2002, 249 (01) :8-21
[8]   Properties and applications of palygorskite-sepiolite clays [J].
Galan, E .
CLAY MINERALS, 1996, 31 (04) :443-453
[9]   USE OF SURFACE COMPLEXATION MODELS IN SOIL CHEMICAL-SYSTEMS [J].
GOLDBERG, S .
ADVANCES IN AGRONOMY, 1992, 47 :233-329
[10]   SORPTION OF NI, ZN AND CD ON SEPIOLITE [J].
HELIOSRYBICKA, E .
CLAY MINERALS, 1985, 20 (04) :525-527