Enhanced Adsorption of Methylene Blue Using Distilled Water Neutralized Red Mud | Chapter 09 | Theory and Applications of Chemistry Vol. 1
This
work is aimed
at improving the
ability of red
mud to remove
methylene blue from
aqueous solution. The efficiency of methylene blue (MB) removal by
untreated red mud was compared to that of red mud neutralized with distilled
water. The pH, surface charge, particle size distribution, chemical
composition, infrared spectrometry
and morphology analyses
were used to
characterize the adsorbents. Batch
experiments without agitation
and filtration were
conducted to determine
the influence of contact
time, solution pH,
temperature, initial dye
concentration, adsorbent dose
and presence of Clˉ, SO₄²ˉ, HPO₄²ˉ and HCO₃ˉ on dye removal. Distilled
water treated red mud (RMD) had improved adsorbent properties than raw red mud
(RM). For all the parameters tested, RMD showed higher removals of MB compared
to RM. The fitting order for tested isotherm models was: Langmuir
>Dubinin–Radushkevich > Freundlich for RMD and Freundlich >
Dubinin–Radushkevich > Langmuir for RM.
Monolayer adsorption capacities
of RMD and
RM were found
to be 17.123
and 4.221 mg/L respectively. Pseudo-second-order kinetic
model suited well
than other tested
kinetic models. Equilibrium was
attained in 24 hours, and the order of shifting of equilibrium to the right as
well as the rate of uptake is: MB on RMD > MB on RM. MB removal was found to
be more endothermic, more spontaneous and more favourable on RMD than on RM.
Desorption experiments using acetone gave good
results up to
four cycles. MB
can easily be
removed from waste
water using distilled
water neutralized red.Water modified red mud is relatively efficient as
other used materials for MB removal (Table 5), so it was concluded that red mud
modified with distilled water can be used for industrial applications in
removing methylene blue from various real effluents released from various types
of industries such as
chrome plating, textile
dyeing, leather tanning
and photolithographic industries. Furthermore, red
mud is very
cheap as compared
to other adsorbents
so easily available.
Also modification of red mud with water is a cheaper process with no
risk of introducing other chemicals on to it
as opposed to
other neutralization methods
that use mineral acid,
heat and other
chemicals. Distilled water neutralized
red mud is more efficient in
removing methylene blue from waste water than untreated red mud.
Author(s) Details
Cornelius Tsamo
Department of Chemistry,
Higher Teachers’ Training College Maroua, P.O.Box 55 Maroua, Cameroon and
Laboratoire des Matériaux et Chimie Inorganique Industrielle, University of
Ngaoundere, Cameroon.
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