Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9676084 | Colloids and Surfaces A: Physicochemical and Engineering Aspects | 2005 | 7 Pages |
Abstract
Kinetics of adsorption of benzoate and salicylate onto the natural hematite surfaces have been carried out at pH 5 and at a fixed ionic strength (I = 1 Ã 10â4 mol dmâ3). The state of equilibrium was attained at 144 and 70 h for benzoate and salicylate, respectively. Adsorption behaviour of benzoate and salicylate onto the natural hematite was studied over a wide range of pH at a fixed I = 5 Ã 10â4 mol dmâ3 NaCl and at different temperatures. The adsorption isotherms for both the adsorbates were Langmuir type up to pH 8. The Îmax for benzoate is â2.7-13.7 times more than that of salicylate depending on the pH of the suspension. Unlike benzoate, salicylate is not only adsorbed at one surface site but also covers around three or more surface sites of hematite surface. The rate constant for adsorption, K1 for salicylate onto the natural hematite is greater than that of benzoate and increases with the increase in temperature and â4 times greater at a fixed temperature. The activation energy for the adsorption of salicylate onto the natural hematite is 2.9 times more than that of benzoate on the same adsorbent resulting in lower Îmax.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Manash R. Das, Dipak Bordoloi, Prakash C. Borthakur, Sekh Mahiuddin,