Removal of reactive textile dyes (Remazol Brillant Blue R and Remazol Yellow) by surfactant‐modified natural zeolite

Abstract

In this study, surfactant-modified zeolite (SMZ) was used to remove Remazol Brillant Blue R and Remazol Yellow reactive dyes from aqueous solutions. The influences of suspension pH, temperature, agitation rate, and the SMZ dosage on reactive dyes removal and adsorption capacity were investigated by conducting a series of batch adsorption experiments. The adsorption kinetics was tested for pseudo-firstorder, pseudo-second order, intraparticle diffusion model, Elovich, and Bangham models, and rate constants of the kinetic models were calculated. Equilibrium isotherms for the adsorption of reactive dyes were analyzed by the Freundlich, Langmuir, Dubinin-Radushkevich, and Tempkin isotherm models. The Langmuir monolayer adsorption capacities of Remazol Brillant Blue R and Remazol Yellow were estimated as 13.9 and 38.31 mg/g, respectively. The adsorption rate was rapid; more than half of the adsorbed Remazol Brillant Blue R was removed in the first 60 min and of Remazol Yellow in the first 30 min. Thermodynamic parameters such as DH 0 , DS 0 , and DG 0 , at 208C, were found to be 5.2126 kJ/mol, 0.0273 kJ/mol K, and 22.7969 kJ/mol (Remazol Brillant Blue R), and 29.9747 kJ/mol, 0.10875 kJ/mol K, and 21.8900 kJ/mol (Remazol Yellow), respectively.

Adsorption of Orange II dye in aqueous solution onto surfactant-coated zeolite: Characterization, kinetic and thermodynamic studies

“…DG°, DH°and DS°were calculated the slope and intercept of van't Hoff plot of ln K C versus 1/T. The positive value of DH o (+82.79 kJ/mol) confirmed the endothermic nature of the adsorption of Orange II onto HCZ while the positive DS o (0.27 kJ/k mol) (see Table 2) implied the increased in randomness at the solid-solute interface during the adsorption process [2]. However, the low value of DS o also indicated that no remarkable changes in entropy took place during the adsorption [27].…”

“…Surfactant modified zeolite [2,11,13,14], bentonite [24,25], palygorskites [12] exhibit substantially enhanced adsorption of organic solutes from aqueous solutions. The proposed interaction mechanism is the partitioning of organic solutes into the organic solvent-like hydrophobic phase created by the alkyl chains of the surfactant.…”

“…More than 10-15% of synthetic dyes produced are lost as effluent and pose a major threat to the health of ecosystem [1]. In some cases, the presence of less than 1 ppm dye is clearly visible to impair the visual impacts of rivers and lakes [1,2]. Azo are the most popular and constitute about 70% of all used dyes [3].…”

“…Traditionally, dyes are eliminated from effluents through biochemical and physical processes such as sorption, coagulation, chemical degradation, advanced oxidation, photocatalysis and biodegradation [4][5][6]. Due to the large content of aromatic compounds and the stability of modern dyes, biological treatments are ineffective methods to degrade dyes [1][2][3].…”

Investigation of adsorption of the dyestuff astrazon red violet 3rn (basic violet 16) on montmorillonite clay

“…The Langmuir isotherm is based on the assumption that maximum adsorption corresponds to a saturated monolayer of dye molecules on the adsorbent surface. The energy of adsorption is constant and there is no transmigration of adsorbate in the plane of the surface of montmorillonite Kuleyin and Aydin, 2011;TehraniBagha et al, 2011).…”