Oguanobi, N. C.
Department of Chemical Engineering, Michael Okpara University Of Agriculture, P. M. B. 7267, Umudike Abia State, Nigeria.
Okonkwo, G.
Department of Chemical Engineering, Michael Okpara University Of Agriculture, P. M. B. 7267, Umudike Abia State, Nigeria.
Onukwuli, O. D.
Department of Chemical Engineering, Nnamdi Azikiwe University, P. M. B. 5025, Awka, Anambra State, Nigeria
Ude, C. N.
Department of Chemical Engineering, Michael Okpara University Of Agriculture, P. M. B. 7267, Umudike Abia State, Nigeria.
Anike, E. N.
Department of Chemical Engineering, Michael Okpara University Of Agriculture, P. M. B. 7267, Umudike Abia State, Nigeria.
ABSTRACT
Congo
Red Dye (CRD) is a hazardous dye of environmental concern due to its complex
molecular structure and artificial origin, which make it non-biodegradable. The
research focused on using the physico-chemical method to remove CRD from
aqueous solution by utilizing the adsorptive qualities of raw Ihiala clay
(RIC). The batch system was applied to evaluate the effect of
process-independent variables on the adsorption process. The adsorption
equilibrium was investigated using Langmuir, Freundlich and Jovanovic models.
The adsorption kinetics was investigated using the pseudo-first order (PSO),
the pseudo-second order (PRO) and intra-particle diffusion (IPD) models. The
thermodynamic properties ∆S, ∆H, ∆G, and Ea were determined. The optimum
removal efficiency of CRD was predicted using the Response Surface Methodology
(RSM) model. The activation resulted in an increase in surface area. Maximum
color removal of 68.8% was observed at pH 2, an adsorbent dosage of 0.5 g, an
adsorbent particle size of 75 µm, an initial dye concentration of 100 mg/l, a
contact time of 120 min, and a temperature of 323 k. A maximum adsorption
capacity of 27.5 mg/g was obtained experimentally. The equilibrium adsorption
data was best described by Langmuir model. The kinetic adsorption data was best
fitted to PSO while the IPD is not slowest of the rate processes that
determines the overall order. Thermodynamic results suggested an endothermic,
favorable, spontaneous, and physical adsorption process. RSM show high
statistical significance in modeling the adsorption process. The obtained
results confirm RIC as a reliable, cost-effective adsorbent for CRD removal
from effluents.
Keywords: adsorption, Congo red, kinetics, modelling, thermodynamics.
https://doi.org/10.33922/j.ujet_v10i2_3
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Published
Wednesday, August 21, 2024
Issue
Vol. 10 No. 2, December 2024
Article Section
GENERAL
The contents of the articles are the sole opinion of the author(s) and not of UJET.
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