Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

Brazilian Journal of Chemical Engineering

G. L. Dotto¹  M. L. G. Vieira¹  V. M. Esquerdo¹  L. A. A. Pinto¹ 

[1] ,Federal University of Rio Grande School of Chemistry and Food Rio Grande RS ,Brazil

关键词: Biosorption;    Spirulina platensis;    Azo dyes;   

DOI  :  10.1590/S0104-66322013000100003

来源: SciELO

【 摘 要 】

The equilibrium and thermodynamics of azo dye (tartrazine and allura red) biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS) were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium experimental data (R²>0.99 and ARE<5.0%) and the maximum biosorption capacities were 363.2 and 468.7 mg g-1 for tartrazine and allura red, respectively, obtained at 298 K. The negative values of ΔG and ΔH showed that the biosorption of both dyes was spontaneous, favorable and exothermic. The positive values of ΔS suggested that the system disorder increases during the biosorption process.

【 授权许可】

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