Title: Elimination of hexavalent chromium from polluted water using specific type of bentonite clay as adsorbent

Authors: Mohammed Ali Rashid Hameed; Mohammed Jaafar Ali Alatabe

Addresses: Department of Environmental Engineering, College of Engineering, University of Mustansiriyah, P.O. Box 14150, Bab-al-Mu'adhem, Baghdad, Iraq ' Department of Environmental Engineering, College of Engineering, University of Mustansiriyah, P.O. Box 14150, Bab-al-Mu'adhem, Baghdad, Iraq

Abstract: Specific bentonite was studied to remove Cr⁺⁶ from water using adsorption. Samples were mixed with 0.5 and 1 gm of bentonite per 100 ml, for one and two hours to reach equilibrium, at temperatures of 20°C, 40°C, 60°C, and pH 7. The absorbent was separated, and water filtered and treated to determine Cr⁺⁶ remaining concentration by light absorption technique. High Cr⁺⁶ removals were obtained. At dosage of 0.5 gm, the removals were 10% to 93.2% at 20°C and one hour mixing. But increased when initial concentrations increased, and mixing time became two hours (52%-95.4%). At 40°C, removals improved for Cr⁺⁶ initial concentrations ≤ 30 mg/l, but had adverse effect on concentrations > 30 mg/l. Adsorption capacity ranged 0.52 mg/gm to 19.08 mg/gm. A dosage of 1 gm improved removals much higher than 0.5 gm did for initial concentrations ≤ 30 mg/L, but little higher for > 30 mg/l.)

Keywords: hexavalent chromium; bentonite clay; adsorption; UV-visible; spectrophotometer; Freundlich isotherm model.

DOI: 10.1504/IJEWM.2022.124686

International Journal of Environment and Waste Management, 2022 Vol.29 No.4, pp.377 - 390

Received: 27 Aug 2019
Accepted: 08 Jun 2020
Published online: 08 Aug 2022 *

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