Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
686292 | Bioresource Technology | 2007 | 10 Pages |
Abstract
The ability of using low-rank Turkish brown coals (Ilgın: BC1, BeyÅehir: BC2, and Ermenek: BC3) to remove Cr(VI) from aqueous solutions was studied as a function of contact time, solution pH, temperature, concentration of metal solutions and amount of adsorbent. Their sorption properties were compared with the activated carbon from Chemviron (AQ-30). Adsorption of Cr(VI) uptake is in all cases pH-dependent showing a maximum at equilibrium pH values between 2.0 and 3.2, depending on the biomaterial, that correspond to initial pH values of 2.3 units for BC1, 3.0 units for BC2 and 3.2 units for BC3 and AQ-30. Batch equilibrium tests showed that the Cr(VI) removal was fitted with Freundlich isotherm and the adsorption reached equilibrium in 80 min. It was proceeding effectively into a short acid pH interval (2.0-3.2) where processes of Cr(VI) sorption are maximized. It was observed that the maximum adsorption capacity of 11.2 mM of Cr(VI)/g for Ilgın (BC1), 12.4 mM of Cr(VI)/g for BeyÅehir (BC2), 7.4 mM of Cr(VI)/g for Ermenek (BC3) and 6.8 mM of Cr(VI)/g for activated carbon (AQ-30) was achieved at pH of 3.0. The rise in temperature caused a slight decrease in the value of the equilibrium constant (Kc) for the sorption of Cr(VI) ion. The Cr(VI) sorption capacities of BeyÅehir and Ilgın brown coals were the same. Ermenek brown coals and activated carbon (AQ-30) showed a similar sorption capacity.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Process Chemistry and Technology
Authors
Gulsin Arslan, Erol Pehlivan,