Improving of understanding of beta-hexachlorocyclohexane (HCH) adsorption on activated carbons by temperature-programmed desorption studies

Passé-Coutrin, Nady; Maisonneuve, Laetitia; Durimel, Axelle; Dentzer, Joseph; Gadiou, Roger; Gaspard, Sarra

Improving of understanding of beta-hexachlorocyclohexane (HCH) adsorption on activated carbons by temperature-programmed desorption studies

2016

In order to understand the interactions between beta-hexachlorocyclohexane (HCH) and chemical groups at activated carbon (AC) surface, the solid samples were hydrogenated aiming to decrease the amounts of oxygenated groups. Two AC samples designated by BagH₂O and BagP1.5 were prepared by water vapor activation and phosphoric acid activation, respectively, of sugarcane bagasse used as an AC precursor. A more simple molecule 1,2,3-trichloropropane (TCP) is used as a model of chlorinated compound. The AC were characterized by infrared, X-ray photoelectron spectroscopy (XPS), Raman resonance spectroscopies, as well as temperature-programmed desorption coupled with mass spectrometry (TPD-MS). BagP1.5 and BagH₂O AC surface contained oxygenated groups. Upon hydrogenation, a decrease of most of these group amxounts was observed for both samples, while hydroxyl groups increased. On the basis of temperature-programmed desorption data obtained for AC samples contaminated with TCP or HCH, it was possible to determine the type of hydrogen bond formed between each AC and HCH.

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