title: The adsorption of basic dye (Astrazon Blue FGRL) from aqueous solutions onto sepiolite, fly ash and apricot shell activated carbon: kinetic and equilibrium studies.
abstract: In this study, sepiolite, fly ash and apricot stone activated carbon (ASAC) were used as adsorbents for the investigation of the adsorption kinetics, isotherms and thermodynamic parameters of the basic dye (Astrazon Blue FGRL) from aqueous solutions at various concentrations (100-300 mg/L), adsorbent doses (3-12 g/L) and temperatures (303-323 K). The result showed that the adsorption capacity of the dye increased with increasing initial dye concentration, adsorbent dose and temperature. Three kinetic models, the pseudo-first-order, second-order, intraparticle diffusion, were used to predict the adsorption rate constants. The kinetics of adsorption of the basic dye followed pseudo-second-order kinetics. Equations were developed using the pseudo-second-order model which predicts the amount of the basic dye adsorbed at any contact time, initial dye concentration and adsorbent dose within the given range accurately. The adsorption equilibrium data obeyed Langmuir isotherm. The adsorption capacities (Q0) calculated from the Langmuir isotherm were 181.5 mg/g for ASAC, 155.5 mg/g for sepiolite and 128.2 mg/g for fly ash at 303 K. Thermodynamical parameters were also evaluated for the dye-adsorbent systems and revealed that the adsorption process was endothermic in nature.
authors.affiliation: Cumhuriyet University, Department of Environmental Engineering, 58140 Sivas, Turkey.
authors.forename: B
authors.initials: B
authors.lastname: Karagozoglu
authors.forename: M
authors.initials: M
authors.lastname: Tasdemir
authors.forename: E
authors.initials: E
authors.lastname: Demirbas
authors.forename: M
authors.initials: M
authors.lastname: Kobya
mesh_terms: D000327:Adsorption; D002244:Carbon; D002606:Charcoal; D060729:Coal Ash; D007700:Kinetics; D017633:Magnesium Silicates; D052638:Particulate Matter; D012394:Rosaniline Dyes / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: C511329:Astrazon Blue FGRL; D060729:Coal Ash; D017633:Magnesium Silicates; D052638:Particulate Matter; D012394:Rosaniline Dyes; D014874:Water Pollutants, Chemical; D002606:Charcoal; D002244:Carbon; C001671:magnesium trisilicate