SciELO - Scientific Electronic Library Online

 
vol.15 número3Preparação e caracterização de organobentonita modificada com ionenos alifáticosEstabelecimento de ciclo de cura de pré-impregnados aeronáuticos índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

Compartilhar


Polímeros

versão impressa ISSN 0104-1428versão On-line ISSN 1678-5169

Resumo

SPINELLI, Viviane A.; LARANJEIRA, Mauro C. M.; FAVERE, Valfredo T.  e  KIMURA, Irene Y. Kinetics and equilibrium of adsorption of oxyanions Cr (VI), Mo (VI) and Se (VI) by quaternary ammonium chitosan salt. Polímeros [online]. 2005, vol.15, n.3, pp.218-223. ISSN 1678-5169.  https://doi.org/10.1590/S0104-14282005000300013.

Quaternary chitosan salt was synthesized in the presence of glycidyl trimetyl ammonium chloride. The polymer was characterized by spectroscopic techniques: infrared, 13C and 1H NMR, while the amount of quaternary ammonium groups was obtained by condutimetry. The removal of Cr (VI), Mo (VI) and Se (VI) from aqueous solutions was carried out in batch adsorption processes. The process seemed to be pH dependent for Cr (VI) and Se (VI) with an optimum pH ranging from 4.0 to 6.0; while for Mo (VI) the adsorption remained almost constant within the range between 4.0 and 11.5. The Langmuir isotherm model provided the best fit of the equilibrium data over the whole concentration investigated. In the experiment one gram of cross-linked quaternary chitosan salt adsorbed 68.3 mg of chromium, 63.4 mg of molybdenum and 90.0 mg of selenium. The adsorption process followed a pseudo second-order kinetic rate equation and the equilibrium regarding the three ions was reached after 200 minutes. The studies from X-ray dispersive energy showed that the main adsorption mechanism is ionic exchange among Cl- groups on the polymer surface by oxyanions from solution and the anionic exchanger showed the following selectivity order: Cr (VI) > Mo (VI) > Se (VI).

Palavras-chave : Adsorption; chromium (VI); molybdenum (VI); selenium (VI); quaternary chitosan salt.

        · resumo em Português     · texto em Português     · Português ( pdf )

 

Creative Commons License Todo o conteúdo deste periódico, exceto onde está identificado, está licenciado sob uma Licença Creative Commons