Utilization of Cactus Peel as Bioadsorbent For The Removal of Reactive Red Dyes from Textile Dye Effluents
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Date
2018-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Numerous dye staffs are used in textile industries to paint their products and produces high
discharge rate of wastewater with high load of pollutants. Now the presence of dyes in the
aquatic systems has become a serious environmental problem. currently bioadsorbents have
become desirable for the removal of dyes from textile dye effluents due to their good
performance, low cost, simple design, no sludge generation and their accessibility. In this
study, the biosorption characteristics and feasibility of cactus peel have been analyzed to
remove reactive dyes from aqueous solutions. Batch biosorption experiments were carried out
for the biosorption of reactive dye molecule from aqueous solution onto the cactus peel
adsorbent at constant room temperature of 25
X
o
C
and agitation speed 200rpm.The effects of
diverse process parameters like solution pH, biosorbent dosage, contact time and initial
concentration were studied in batch adsorption.
For the equilibrium studies, Langmuir and Freundlich isotherm models were applied to
identify the relationship between the concentration of dye ions in the solution and the amount
of dye ions adsorbed to the cactus peel adsorbent. The interaction effect of process variables
was studied using response surface methodology. The results from the experiments showed
that, removal efficiency of reactive red dye was found to increase with lower initial dye
concentration, lower solution pH, maximum biosorbent dosage and higher contact time. The
effective solution pH, initial dye concentration, biosorbent dose and contact time on the
reactive red dye removal efficiency of the cactus peel biosorbent was found to be 3.0, 40 mg/l,
6g and 120min respectively for batch biosorption studies. At these experimental conditions the
removal efficiency of reactive red dye using cactus peel adsorbent was found to be 99.43%.
regression coefficient of the Langmuir isotherm (R
2
=0.9935) is higher than that of the
Freundlich isotherm equation model (R
2
= 0.9722). Thus, it is a practical and good evidence
that the biosorption of the reactive red dye onto the cactus peel biosorbent follows the
Langmuir isotherm represents the best fitting of experimental data than the Freundlich
isotherm equation. Hence, this is indicative of complete mono-layer coverage of the dye on
cactus peel surface and it was found to be 2.1066 mg/g. Biosorption kinetics was determined
using pseudo first order and pseudo second order models and it was found that pseudo-secondorder
model
mechanism
is
the
finest
model
for
biosorption
of
reactive
red
dye
onto
powdered
cactus
peel.
Description
Keywords
Biosorption, cactus peel, equilibrium, Isotherm models, kinetic models, Reactive dye