http://lattes.cnpq.br/8314195354939086; GALLINDO, Andrezza de Araújo Silva.
Resumo:
The treatment of water contaminated by toxic metals using ion exchange with zeolites is
becoming attractive due to its low capital costs and high potential for removal capacity.
Mathematical modeling of this process allows for operational control and estimation of the
ability to remove these metals. In this work, the kinetic modeling was performed based on
finite bath experimental data, with Intraparticle Diffusion (IPD) and External Liquid Film
Mass Transfer (MTEF) models. The models Thomas (TH), YoonNelson
(YN) and Solid
Film Mass Transfer (MTSF) were used to estimate the saturation time, ion exchange capacity
and sizing variables of a fixed bed column. For the finite bath system, the results showed that
the mass transfer was better represented by the IPD phenomenon. The breakthrough curve
obtained by the Aspen Adsorption® (MTSF) model presented the best fit, compared with
experimental data, with R2
≥0.9923. The average ion exchange capacities calculated for
MTSF, TH and YN were respectively 2.22, 2.12 and 2.07 meq Zn2+.g1
of zeolite. The model
simulated with Aspen Adsorption was also used to analyze the continuous system behavior,
by varying the height of the bed. It was observed that increasing the height, the saturation
time and ion exchange capacity also increase, while reducing the height makes axial
dispersion the predominant mass transfer phenomenon, which reduces the diffusion of Zn2+
(aq)
ions.