Tratamento da vermiculita por ionização escalonada para remoção de íons cálcio associados à dureza da água
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2024-10-29Autor
Lima, Arthur Felipe de Souza
http://lattes.cnpq.br/8742357281074301
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Vermiculite has cationic exchange properties, allowing its use as an adsorbent for the
removal of metal ions in purification and water treatment processes. In recent years,
research on the use of vermiculite clay as adsorbents is being developed aimed at
more sustainable solutions. This study investigated the potential of ionized modified
vermiculite as calcium ion adsorbent material in aqueous medium. The first step
consisted of separating the samples of vermiculite, which were classified
granulometrically and washed with bidestilled water. The activation of clay was
performed with solutions of graduated concentrations of sodium chloride and
potassium cloride salts. Subsequently, a study was conducted to determine the zero
load point of vermiculite in nature, establishing the best pH parameter in the process
of cation adsorption. Trials at different time intervals were conducted to determine the
balance time. Kinetic analyses, adsorption isotherms and thermodynamic adsorption
trials were carried out to understand the mechanism of calcium ion adsorbtion in
ionized vermiculite. The clay was characterized by means of analytical techniques
MEV, EDS, DRX and FRX. The ionization process achieved the proposed targets in
relation to the graduation. Vermiculite treated with 100% NaCl showed significantly
higher calcium ion removal in aqueous solution. Through analysis with MEV-FEG, no
significant differences were found in the structure of vermiculite compared to
vermiculite in nature, indicating that the ionization process did not substantially affect
its morphology. After regeneration, the adsorbents showed increased adsorption
capacity. Adsorption was observed as an endothermic process.