Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
583038 | Journal of Hazardous Materials | 2008 | 9 Pages |
Abstract
Batch adsorption of fluoride onto manganese dioxide-coated activated alumina (MCAA) has been studied. Adsorption experiments were carried out at various pH (3-9), time interval (0-6Â h), adsorbent dose (1-16Â g/l), initial fluoride concentration (1-25Â mg/l) and in the presence of different anions. Adsorption isotherms have been modeled using Freundlich, Langmuir and Dubinin-Raduskevich isotherms and adsorption followed Langmuir isotherm model. Kinetic studies revealed that the adsorption followed second-order rate kinetics. MCAA could remove fluoride effectively (up to 0.2Â mg/l) at pH 7 in 3Â h with 8Â g/l adsorbent dose when 10Â mg/l of fluoride was present in 50Â ml of water. In the presence of other anions, the adsorption of fluoride was retared. The mechanism of fluoride uptake by MCAA is due to physical adsorption as well as through intraparticle diffusion which was confirmed by kinetics, Dubinin-Raduskevich isotherm, zeta-potential measurements and mapping studies of energy-dispersive analysis of X-ray.
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Authors
Sushree Swarupa Tripathy, Ashok M. Raichur,