Removal of Anions from Solution by Calcined Hydrotalcite and Regeneration of Used Sorbent in Repeated Calcination-Rehydration-Anion Exchange Processes

[img]PDF - Authorized users only
Language: English
153Kb
Title:Removal of Anions from Solution by Calcined Hydrotalcite and Regeneration of Used Sorbent in Repeated Calcination-Rehydration-Anion Exchange Processes
Creators:
Kovanda, František
Kovácsová, Eva
Koloušek, David
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 64, 9, pp. 1517-1528
Uncontrolled Keywords:Anion exchangers, Waste water treatment, Thermal decomposition, Rehydration, Hydrotalcite, Crystal structure reconstruction

Abstract

Synthetic hydrotalcite calcined at 350-550 °C was used for the removal of arsenate, chromate, and vanadate ions from water solutions. The initial anion concentrations were 0.002 mol&nbsp;l<sup>-1</sup>. The sorption isotherms were measured at 20 °C and at neutral pH. The Langmuir adsorption isotherm was used for the sorption capacity evaluation. The ability of the calcined hydrotalcite to remove the anions from solution decreased in the order of vanadate - arsenate - chromate. The hydrotalcite calcined at 450 °C exhibited the best sorption ability for all the anions. The sorbed anions were released by anion exchange in a carbonate-containing solution and the hydrotalcite after subsequent calcination was used again for the removal of anions. The repeating cycles calcination-rehydration-anion exchange gradually reduced the adsorption capacity of the hydrotalcite. The sorption capacity decreased by 50% after the first two cycles but it did not change significantly in the subsequent cycles. When chromate anions were adsorbed, the decrease in sorption capacity was not observed during repeated calcination-rehydration-anion exchange cycles. The change in the sorption capacity was influenced by the ability of calcined hydrotalcite to regenerate the layered crystal structure during the rehydration process. <p>

Title:Removal of Anions from Solution by Calcined Hydrotalcite and Regeneration of Used Sorbent in Repeated Calcination-Rehydration-Anion Exchange Processes
Creators:
Kovanda, František
Kovácsová, Eva
Koloušek, David
Uncontrolled Keywords:Anion exchangers, Waste water treatment, Thermal decomposition, Rehydration, Hydrotalcite, Crystal structure reconstruction
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:64
Number:9
Page Range:pp. 1517-1528
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19991517UNSPECIFIED
ID Code:1576
Item Type:Article
Deposited On:06 Feb 2009 17:10
Last Modified:06 Feb 2009 16:10

Citation

Kovanda, František; Kovácsová, Eva; Koloušek, David (1999) Removal of Anions from Solution by Calcined Hydrotalcite and Regeneration of Used Sorbent in Repeated Calcination-Rehydration-Anion Exchange Processes. Collection of Czechoslovak Chemical Communications, 64 (9). pp. 1517-1528. ISSN 0010-0765

Repository Staff Only: item control page