American Journal of Applied Sciences

Supercritical CO2 Extraction of Heavy Metals Cu, Zn and Cd from Aqueous Solution using D ithizone as Chelating Agent

Jeton Halili, Altin Mele, Tahir Arbneshi and Ilir Mazreku

DOI : 10.3844/ajassp.2015.284.289

American Journal of Applied Sciences

Volume 12, Issue 4

Pages 284-289

Abstract

Metal ions in liquid samples can be extracted by supercritical CO2, containing a suitable ligand. This paper presents the first experimental data for the extraction of three heavy metals Cu, Zn and Cd from aqueous samples in the presence of Dithizone as chelating agent. Extractions by supercritical CO2 have been performed at 120 bars with 50°C used dynamic technique. After adding the CO2 on the aqueous metal solution, the pressure and temperature were set and extraction was performed in three periodical times; 30, 60 and 120 min at constant temperature and pressure with a flow rate of CO2 2 mL min-1. After the extraction, the CO2 was released slowly through a restrictor. Methanol was used as a modifier (v/v) 10% and the pH value was set (10). After the extraction process, the remaining aqueous solution in the extractor was analyzed for its metal content by Atomic Absorption Spectrophotometer (AAS), determining the recovery of the metal by CO2. During dynamic extraction noticed increased of extraction in function of time for all three metals; Cu (61.12-73.52%, RSD = 2.694, n = 3); Zn (78.33-87.00%, RSD = 1.243, n = 3) and Cd (70.60-82.40%, RSD = 2.227, n = 3).

Copyright

© 2015 Jeton Halili, Altin Mele, Tahir Arbneshi and Ilir Mazreku. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.