Adsorption of chlorophyll-a from acetone solution on natural and activated bentonite |
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Authors: | E. Gonz lez Pradas,M. Villafranca S nchez,M. Socí as Viciana,A. Gallego Campo |
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Affiliation: | E. González Pradas,M. Villafranca Sánchez,M. Socías Viciana,A. Gallego Campo |
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Abstract: | The adsorption of chlorophyll-a on bentonite desiccated at 110°C, untreated and acid-treated with H2SO4 solutions over a concentration range between 0·25 and 2·50 mol dm?3, from acetone solution at 25°C has been studied. The adsorption isotherms may be classified as using Giles' classification, as type S (untreated sample and 0·25 mol dm?3 H2SO4-treated sample), type H (0·50 mol dm?3 H2SO4-treated sample) and type L (1·00 and 2·50 mol dm?3 H2SO4-treated samples). This fact suggests that the bentonite surfaces (low, high and medium affinity, respectively) behave in differently relation to the adsorption of the chlorophyll-a molecules. The experimental data points have been fitted to the Freundlich equation in order to calculate the adsorption capacities (Kf) of the samples; Kf values range from 0·43 mg kg?1 for the untreated bentonite up to 108·89 mg kg?1 for the 0·50 M H2SO4-treated bentonite. The removal efficiencies (R) have also been calculated and range from 5·71% for the untreated bentonite up to 85·18% for the 0·50 M H2SO4-treated bentonite. |
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Keywords: | chlorophyll-a adsorption clay activated clay |
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