In the present study peach seed powder (PSP) was used as an adsorbent to remove Acid Blue 25 (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 (PFO), pseudo second order (PSO) and intra-particle diffusion (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 qe 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 qe 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 (qm) 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 (ΔG), enthalpy (ΔH) and entropy (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.

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In this study Juniperus excelsa shavings powder (JESP) was utilized as an adsorbent for the removal of Basic Blue 41 (BB 41) which is one of the common basic dyes, from aqueous solution. The adsorption experiments were carried out in a batch system and effects of initial concentration of dye, interaction time and temperature were investigated. Langmuir, Freundlich and Temkin adsorption isotherms were used to model equilibrium data. According to the results, Freundlich isotherm model becomes more convenient option compared with Langmuir and Temkin models. Freundlich model coefficients are raise as the temperature rises, showing that the adsorption process becomes favorable higher temperature. The kinetic parameters were determined by pseudo first order (PFO), pseudo second order (PSO) and intra-particle diffusion (IPD) models. Results indicated that experimental and calculated qe values are matched to each other. Thus the process fits PSO kinetic model with higher R 2 values than other two models. Kinetic constants become closer to both temperatures and initial concentrations and qe values are increases with increasing concentration of BB 41. Initial dye concentration elevates from 25 to 100 mg L-1 , dye adsorption capacity onto JESP from 3.06 to 16.53 mg g-1 , respectively. Thermodynamic parameters for instance free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were assessed. Enthalpy and entropy of this separation process are determined from 3081.91 J mol-1 and 12.33 kJ mol-1 , respectively. The negative values of ΔG° showed that this separation process was endothermic and natural. The research results demonstrate that JESP may be a substitute than pricey adsorbents for dye removal.