Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
584991 | Journal of Hazardous Materials | 2007 | 6 Pages |
Abstract
Batch adsorption of the chromium(VI) onto Moroccan stevensite pillared by Keggin aluminium hydroxypolycation (Al-stevensite) and cationic surfactant cetyltrimethylammoniumbromide (CTA-stevensite) was investigated. The results showed that the CTA-stevensite has a higher affinity than that of Al-stevensite for chromium(VI) adsorption. The adsorption capacities for natural stevensite, Al-stevensite and CTA-stevensite calculated according to the Dubinin-Kaganer-Radushkevich isotherm (DKR) are 13.7, 75.4 and 195.6 mmol kgâ1, respectively. The study of the pH effect showed that the optimal range corresponding to the Cr(VI) maximum adsorption on Al-stevensite is pH 3.5-6 and that on CTA-stevensite is pH 2-6. The adsorption rates evaluated according to the pseudo-second-order model are 7.2, 207.2 and 178.5 mmol kgâ1 minâ1 for the natural stevensite, Al-stevensite and CTA-stevensite, respectively. The low values of the adsorption energy calculated by (DKR) suggest that anion exchange is the main mechanism that governs the chromate adsorption.
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Authors
Abdelaziz Benhammou, Abdelrani Yaacoubi, Lahbib Nibou, Boumediane Tanouti,