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E u r o S c i C o n C o n f e r e n c e o n
Chemistry
2018
Chemistry 2018
Journal of Organic & Inorganic Chemistry
ISSN 2472-1123
F e b r u a r y 1 9 - 2 0 , 2 0 1 8
P a r i s , F r a n c e
Page 36
T
he inappropriate disposal of wastewater with hexavalent chromium ions
has been causing risks to human health, the environment and industries.
The present study aims to minimize the concentration of dichromate ions
in contaminated effluents using the adsorption technique to remove ions.
Adsorption tests in batch were performed using natural clinoptilolite zeolite
in its activated and functionalized form, where it was possible to evaluate
the efficiency through the removal of contaminating material. The zeolite
modification in order to improve substantially its activity and selectivity was
made through the activation with NaCl and the functionalization with BaCl2.
The modified zeolite was added in a kitassato with a dichromate solution and
stirred with the aid of a magnetic stirrer. The analysis of the ions adsorption
efficiency was determined with statistical support of the center composite
rotational design (CCRD), where the best conditions for three factors was
tested. The adsorption efficiency factors and levels studied was the adsorbent
particle size (ranging from 0.128 mm to 2.03 mm), the adsorbent material
mass (ranging from 1 g to 5 g) and the contact time between zeolite and the
solution (ranging from 0.5 h to 2 h). For the chromium ions adsorption, the best
condition found was using particles with of 0.128 mm, zeolite mass in 3 g and
contact time in 1.25 h at room temperature. The initial chromium concentration
of 25 ppm was based on actual values of wastewater effluents in which the
zeolite would be used after an initial effluent treatment by precipitation. The
application of this adsorbent under the studied conditions for the removal
of hexavalent chromium is sufficient to meet the resolution of the National
Council for the Environment, CONAMA nº 430, which the valid limit for
hexavalent chromium is 0.1 ppm. The chromium sample analysed, reached a
99.6% removal as result, it was possible to reach a final concentration of 0.089
ppm, which is in accord with the limit established by the Brazilian legislation.
The concentration of hexavalent chromium ions present in the sample was
determined by the 3500-Cr (Colorimetric) analysis method of the Standard
Methods for the Examination of Water and Wastewater (1992). The adsorption
isotherm which best represented a hexavalent chromium adsorption, under the
used conditions, was Langmuir, where in concentrations between 10 and 500
ppm, resulted in R2 of 0.96 and Qmax of 13.64 mg/g which is close to Qexp of
12.65 mg/g, indicating that the hexavalent chromium adsorption on the solid
is a propitious physical process.
Biography
B C Ladeira has recently completed his graduation in Chemical
Engineering from Faculdades Integradas de Aracruz – FAACZ
and currently pursuing his Postgraduation in Production En-
gineering at Universidade Cândido Mendes – UCAM. He has
worked as a Research Assistant in the development laborato-
ries of Fibria Celulose SA in Brazil, working with cellulose pulp-
ing and bleaching, physical paper assays and nanocellulose
pilot plant. Currently, he is a trainee in the field of drug product
development at Hovione FarmaCiência SA in Portugal..
brunocapiche@hotmail.comEvaluation of the adsorption efficiency of modified clinoptiliolite zeolite
in the extraction of hexavalent chromium ions
B C Ladeira, J Vassoler, L M D Santana Rocha, T F Bottan
and M S R Gomes
Faculdades Integradas de Aracruz, Brazil
B C Ladeira, J Org Inorg Chem 2018, Volume: 4
DOI: 10.21767/2472-1123-C1-002