World Journal of Engineering and Technology, 2016, 4, 21-37
Published Online February 2016 in SciRes. http://www.scirp.org/journal/wjet
http://dx.doi.org/10.4236/wjet.2016.41003
How to cite this paper: Igwegbe, C.A., Onyechi, P.C., Onukwuli, O.D. and Nwokedi, I.C. (2016) Adsorptive Treatment of Tex-
tile Wastewater Using Activated Carbon Produced from Mucuna pruriens Seed Shells. World Journal of Engineering and
Technology, 4, 21-37. http://dx.doi.org/10.4236/wjet.2016.41003
Adsorptive Treatment of Textile Wastewater
Using Activated Carbon Produced from
Mucuna pruriens Seed Shells
Chinenye Adaobi Igwegbe
1*
, Pius Chukwukelue Onyechi
2
, Okechukwu Dominic Onukwuli
1
,
Ikenna Chukwudi Nwokedi
1
1
Department of Chemical Engineering, Nnamdi Azikiwe University, Awka, Nigeria
2
Department of Industrial and Production Engineering, Nnamdi Azikiwe University, Awka, Nigeria
Received 6 October 2015; accepted 11 January 2016; published 18 January 2016
Copyright © 2016 by authors and Scientific Research Publishing Inc.
This work is licensed under the Creative Commons Attribution International License (CC BY).
http://creativecommons.org/licenses/by/4.0/
Abstract
Mucuna pruriens seed shells (abundantly available agricultural waste) were processed, treated
and activated using 60% orthophosphoric acid for removal of congo red and malachite green from
an aqueous solution. Its physicochemical properties and its removal efficiencies on the textile
dyes were determined. The effect of particle size, adsorbent dose, initial pH of solution, adsorbate
concentration and contact time on the process of adsorption was investigated. The equilibrium,
kinetic and thermodynamic properties of the dyes removal were also investigated. The experi-
mental data were modeled using linear regression method of analysis. The correlation coefficient
was used as a criterion for model adequacy and acceptance. Sum of squares error was used to va-
lidate the isotherm models. The pseudo second-order kinetic model was found to best correlate
the experimental data. The intraparticle diffusion is not the only rate controlling step in the
process. The experimental data were found to follow the Langmuir, Freundlich and Tempkin iso-
therm models. The negative free energy indicated that the adsorption processes were sponta-
neously feasible. The process of adsorption has been found to be endothermic in nature. The re-
moval of malachite green was found to be more spontaneous and feasible than the removal of
congo red on the adsorbent. From the study it was deduced that the Mucuna pruriens seed shells
activated with phosphoric acid were found to be a good adsorbent for the treatment of textile
wastewater containing congo red and malachite green.
Keywords
Adsorption, Congo Red, Isotherm, Kinetics, Malachite Green, Mucuna pruriens Seed Shells,
Thermodynamics
*
Corresponding author.