Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
583505 | Journal of Hazardous Materials | 2008 | 5 Pages |
Abstract
Application of riverbed sand, a non-toxic substance for the removal of Cr(VI) for aqueous solutions has been investigated. Removal of Cr(VI) was dependent on initial concentration and removal increased from 43.2% to 74.3% by decreasing initial concentration from 7.5 Ã 10â5 M to 1.0 Ã 10â5 M at 25 °C, 1.0 Ã 10â2 M NaClO4 ionic strength and 100 rpm. Higher removal was obtained at particles of smaller sizes of the adsorbent. Removal decreased from 74.3% to 40.7% by increasing temperature from 25 °C to 35 °C exhibiting exothermic nature of the process of removal. Thermodynamic parameters, namely change in free energy (ÎG°), enthalpy (ÎH°) and entropy (ÎS°), were calculated and were found to be â0.81 kcal molâ1, â17.21 kcal molâ1 and 56.94 cal molâ1, respectively at 25 °C. pH of the solution has pronounced effect on the removal and higher removal was obtained in acidic pH ranges, maximum (74.3%) being at 2.5 pH.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Health and Safety
Authors
Y.C. Sharma, B. Singh, A. Agrawal, C.H. Weng,