Comparison study on the adsorption of a synthetic textile dye using bentonite and surfactant modified bentonite

Abstract

Dyes entering waterways are less focused on since there are more reports of heavy metals, organic and inorganic compounds pollution. The main aim of this paper was to evaluate the adsorptive potential of Natural Bentonite (NB), Cetyltrimethylammonium Bromide Modified Bentonite (CTAB-Ben) and Cetylpridium Bromide Modified Bentonite (CPB-Ben) on an Anionic Azo Dye. The materials used for adsorption of Acid Blue 25 (AB 25) dye from an aqueous solution were identified using physical characteristics such as XRD, SEM, SSA and various test effects. The test effects efficiency of natural and surfactant modified Bentonite in adsorption of AB 25 dye has been applied as a function of equilibrium concentrations, pH, contact times and temperatures using the batch technique. The adsorption of AB 25 by CTAB-Ben and CPB-Ben compared to NB showed a clear increase in adsorption for the effects of equilibrium concentrations (74.033±0.153 and 59.833±0.153 compared to 6.877±0.001), pH (24.065±0.002 and 23.578±0.002 compared to 5.990±0.003), contact times and temperatures (45.55±0.05 and 37.42±0.02 compared to 12.18±0.01) respectively. Adsorption isotherm of CTAB-Ben and CPB-Ben resulted in (R2= 0.96) and (R2= 0.93, 0.92) for Langmuir and Freundlich compared to (R2=0.94) and (R2=0.89) of NB respectively. From the comparison showed by increase in adsorption percentages (80-88%), both surfactants were better compared to NB (20%). However, in modified materials, CTAB-Ben is better compared to CPB-Ben based on the Qe values of all the test effects.