The removal and recovery of Cr(VI) by Li/Al layered double hydroxide (LDH)

被引:70
作者
Hsu, L. C.
Wang, S. L.
Tzou, Y. M. [1 ]
Lin, C. F.
Chen, J. H.
机构
[1] Natl Chung Hsing Univ, Dept Soil & Environm Sci, Taichung 40227, Taiwan
[2] Natl Chung Hsing Univ, Ctr Nanosci & Nanotechnol, Taichung 40227, Taiwan
关键词
Li/Al LDHs; chromium; adsorption; kinetics;
D O I
10.1016/j.jhazmat.2006.08.024
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Hexavalent Cr has been identified as one of the toxic metals commonly present in industrial effluents. Among the treatment techniques developed for removing Cr(VI) from waste waters, sorption is most commonly applied, due to its simplicity and efficiency. However, few adsorbents can be recycled and reused cost-effectively. In this study, the removal and recovery of Cr(VI) from water using Li/Al LDH was investigated. The removal of Cr(VI) by Li/Al LDH was evaluated in a batch mode. The results demonstrated that Cr(VI) adsorption onto Li/Al LDH occurs by replacing the Cl- that originally exists in the interlayer of the adsorbent. The degree of Cr(VI) adsorption observed for Li/Al LDH was relatively high and the process occurred rapidly; however, a portion of adsorbed Cr(VI) was gradually desorbed, due to the Li de-intercalation of Li/Al LDH. Lithium de-intercalation from LVAI LDH with interlayer Cl- and interlayer Cr(VI) follows the first order kinetics and has the activation energies of 76.6 and 41.5 kJ mol(-1), respectively. The properties of thermal unstablility and the high adsorption capacity of Li/Al LDH may lead to the development of an innovative technique for the removal of Cr(VI) from Cr(VI)-containing wastewater. That is, LVAI LDH may be used as an effective adsorbent for the adsorption of Cr(VI) in an ambient environment. Following the adsorptive process, the adsorbed Cr(VI) may be released, using heated water to treat the Cr(VI)-containing Li/Al LDH particles. Through this hydrothermal treatment of the used adsorbent, Cr(VI) can be recovered and the solid product (gibbsite) can be recycled for further use. (c) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码:242 / 249
页数:8
相关论文
共 34 条
[1]   ACUTE TOXICITY OF CHROME ELECTROPLATING WASTES TO MICROORGANISMS - ADSORPTION OF CHROMATE AND CHROMIUM(VI) ON A MIXTURE OF CLAY AND SAND [J].
AJMAL, M ;
NOMANI, AA ;
AHMAD, A .
WATER AIR AND SOIL POLLUTION, 1984, 23 (02) :119-127
[2]  
[Anonymous], 1976, HYDROLYSIS CATIONS
[3]  
[Anonymous], 1995, Standard methods for the examination of water and wastewater, V19th
[4]   Synthesis and structure of the gibbsite intercalation compounds [LiAl2(OH)(6)]X {X=Cl, Br, NO3} and [LiAl2(OH)(6)]Cl center dot H2O using synchrotron X-ray and neutron powder diffraction [J].
Besserguenev, AV ;
Fogg, AM ;
Francis, RJ ;
Price, SJ ;
OHare, D ;
Isupov, VP ;
Tolochko, BP .
CHEMISTRY OF MATERIALS, 1997, 9 (01) :241-247
[5]  
Burba J. L. I., 1982, U. S. Patent, Patent No. 4348295
[6]  
BURROWS D, 1983, CHROMIUM METABOLISM, P138
[7]   INCORPORATION OF PHTHALOCYANINES BY CATIONIC AND ANIONIC CLAYS VIA ION-EXCHANGE AND DIRECT SYNTHESIS [J].
CARRADO, KA ;
FORMAN, JE ;
BOTTO, RE ;
WINANS, RE .
CHEMISTRY OF MATERIALS, 1993, 5 (04) :472-478
[8]   HYDROTALCITE-TYPE ANIONIC CLAYS: PREPARATION, PROPERTIES AND APPLICATIONS [J].
Cavani, F. ;
Trifiro, F. ;
Vaccari, A. .
CATALYSIS TODAY, 1991, 11 (02) :173-301
[9]  
Cotton FA, 1995, BASIC INORGANIC CHEM
[10]  
Fisher J A, 1990, CHROMIUM PROGRAM