Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

Abstract

-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 (R 2 >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.

Removal of FD&C Red No.40 Food Dye from an Aqueous Solution by Vine-Trimming Waste

“…There are not many studies that deal with the adsorption of food dyes using various adsorbents. The existing ones deal with the adsorption of acid blue 9 and food yellow 3 using chitosan [8], [9], the adsorption of sunset yellow dyes on CaAl-LDH-NO 3 [10], the adsorption of FD&D Red No.40 by means of chitosan [11]- [14], the adsorption of Brilliant Blue food dye with hen feathers [15], the adsorption of Tartrazine, Allura Red, Sunset Yellow and Indigo Carmine food dyes on Lewatit MonoPlus M-600 [16] and tartrazine allura red adsorption over Spirulina platensis [17].…”

Biosorption of Organic Dyes: Research Opportunities and Challenges

“…Dogar et al [39] studied the biosorption of methylene blue (MB) from aqueous solutions using green algae Ulothrix sp. Dotto et al [43] investigated the equilibrium and thermodynamics of the biosorption of azo dyes onto Spirulina platensis. and MB.…”

The use of a forest waste biomass, cone ofPinus brutiafor the removal of an anionic azo dye Congo red from aqueous medium

“…To analyze cone biomass interaction with CR, experimental data points were fitted to the Langmuir [33], Freundlich [34], and Sips [35] empirical models, which are the most frequently used two-and three-parameter equations in the literature to describe the non-linear equilibrium between adsorbed pollutant onto the cells (Q e ) and pollutant in solution (C e ) at a constant temperature. The Langmuir isotherm model assumes uniform adsorption energy onto the adsorbent surface.…”

“…In order to optimize the design of an adsorption system, it is important to establish the most appropriate correlation describing the equilibrium curve. Several equilibrium adsorption isotherm models are available, and the most common ones are the mono-layer adsorption developed by Langmuir [33], the multi-layer adsorption of Freundlich [34], and the Sips isotherm [35]. Experimental data of CR on the cone biomass of P. brutia were fitted to the isotherm models using Origin software and the graphical representations of these models are presented in Fig.…”