Adsorption of Acid Blue 25 on peach seed powder: Isotherm, kinetic and thermodynamic studies

Authors : Ali Rıza KUL, Adnan ALDEMİR, Hasan ELİK

Pages : 233-242

Doi:10.35208/ert.650398

View : 16 | Download : 11

Publication Date : 2019-12-31

Article Type : Research Paper

Abstract :In the present study peach seed powder insert ignore into journalissuearticles values(PSP); was used as an adsorbent to remove Acid Blue 25 insert ignore into journalissuearticles values(AB25); a common basic dye, from aqueous solution. The adsorption experiments were carried out in a batch system and the effects of initial concentration, interaction time and temperature were investigated. The Langmuir, Freundlich and Temkin adsorption isotherms were used to model the equilibrium data. The kinetic parameters were determined by the pseudo first order insert ignore into journalissuearticles values(PFO);, pseudo second order insert ignore into journalissuearticles values(PSO); and intra-particle diffusion insert ignore into journalissuearticles values(IPD); models. According to the results, the Freundlich isotherm model is a more convenient option compared with the Langmuir and Temkin models. The Freundlich model coefficients increased as the temperature increased, which shows that the adsorption process becomes more favorable with higher temperature. The experimental and calculated q e values close to one another indicated that this process fits the PSO kinetic model with higher R 2 values than the other two models. Kinetic constants become closer to both the temperatures and initial concentrations and q e values increases with the increasing concentration of AB25. The initial dye concentration increased from 25 to 150 mg L -1 , while the dye adsorption capacity onto PSP increased from 4.80 to 39.01 mg g -1 , from 5.57 to 44.27 mg g -1 and from 6.80 to 49.22 mg g -1 for 298, 308 and 323 K, respectively. The monolayer adsorption capacity insert ignore into journalissuearticles values( q m ); of PSP was determined to be 56.18, 64.94, 95.24 mg g -1 for 298, 308 and 323 K, respectively. Thermodynamic parameters for free energy insert ignore into journalissuearticles values( ΔG );, enthalpy insert ignore into journalissuearticles values( ΔH ); and entropy insert ignore into journalissuearticles values( ΔS ); of the separation process were determined as -1737,1 J mol -1 , 14.776 kJ mol -1 and 55,413 J mol -1 , respectively. The negative values of ΔG o showed that this separation process was endothermic and natural. The results of the present study demonstrated that PSP can be used as an alternative material in dye removal.  
Keywords : Peach seed powder, dye adsorption, isotherm models, kinetic constants, acid blue 25, thermodynamic parameters