An investigation of Cu(II) adsorption by raw and acid-activated bentonite: a combined potentiometric, thermodynamic, XRD, IR, DTA study

Adsorption of Cu(II) by raw bentonite (RB) and acid-activated bentonite (AAB) samples was investigated as a function of the initial Cu(II) concentration, solution pH, ionic strength, temperature, the competitive and complexation effects of ligands (Cl-, SO4(2-), PO4(3-)). Langmuir monolayer adsorption capacity of the RB (42.41 mg g(-1)) was found greater than that of the AAB (32.17 mg g(-1)). The effect of structural charges on the reactivity of the edge groups was evidenced by the particular proton adsorption behaviour of the bentonite samples. The spontaneity of the adsorption process is established by decrease in DeltaG which varied from -0.34 to -0.71 kJ mol(-1) (RB), -1.13 to -1.49 kJ mol(-1) (AAB) in temperature range 303-313 K. Infrared (IR) spectra of the bentonite samples showed that the positions and shapes of the fundamental vibrations of the OH and Si-O groups were influenced by the adsorbed Cu(II) cations. Differential thermal analysis (DTA) results showed that adsorbed Cu(II) cations have a great effect on the thermal behaviour of the bentonite samples. The X-ray diffraction (XRD) spectra indicated that the Cu(II) adsorption onto the bentonite samples led to changes in unit cell dimensions and symmetry of the parent bentonites.     

Removal of basic dye by modified Unye bentonite, Turkey

The adsorption behavior of crystal violet (CV(+)) from aqueous solution onto raw (RB) and manganese oxide-modified (MMB) bentonite samples was investigated as a function of parameters such as initial CV(+) concentration, contact time and temperature. The Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption models were applied to describe the equilibrium isotherms. The Langmuir monolayer adsorption capacities of RB and MMB were estimated as 0.32 and 1.12 mmol/g, respectively. The mean adsorption energy derived from D-R isotherm for MMB showed that the type of adsorption of dye molecules on this material may be defined as chemical adsorption. The adsorption rate was fast and more than half of the adsorbed-CV(+) was removed in the first 55 min for RB and 5 min for MMB at the room temperature. The pseudo-first-order, pseudo-second-order kinetic and the intraparticle diffusion models were used to describe the kinetic data and rate constants were evaluated. The thermodynamic parameters such as DeltaH, DeltaS and DeltaG were found 117.41 kJ/mol, 41.50 J/(molK), -5.07 kJ/mol (RB) and 21.19 kJ/mol 98.34 J/(molK), -7.84 kJ/mol (MMB) at 295.15 K, respectively. The quite high adsorption capacity and high adsorption rate of MMB will provide an important advantage for using of this material in basic dye solution.     

Adsorption characteristics of Cu(II) and Pb(II) onto expanded perlite from aqueous solution

The adsorption characteristics of Cu(II) and Pb(II) onto expanded perlite (EP) from aqueous solution were investigated with respect to the changes in pH of solution, adsorbent dosage, contact time and temperature of solution. For the adsorption of both metal ions, the Langmuir isotherm model fitted to equilibrium data better than the Freundlich isotherm model. Using the Langmuir model equation, the monolayer adsorption capacity of EP was found to be 8.62 and 13.39 mg/g for Cu(II) and Pb(II) ions, respectively. Dubinin-Radushkevich (D-R) isotherm model was also applied to the equilibrium data and the mean free energies of adsorption were found as 10.82 kJ/mol for Cu(II) and 9.12 kJ/mol for Pb(II) indicating that the adsorption of both metal ions onto EP was taken place by chemical ion-exchange. Thermodynamic functions, the change of free energy (DeltaG degrees ), enthalpy (DeltaH degrees ) and entropy (DeltaS degrees ) of adsorption were also calculated for each metal ions. These parameters showed that the adsorption of Cu(II) and Pb(II) ions onto EP was feasible, spontaneous and exothermic at 20-50 degrees C. Experimental data were also evaluated in terms of kinetic characteristics of adsorption and it was found that adsorption process for both metal ions followed well pseudo-second-order kinetics.     

The sorption of lead(II) ions on rice husk ash

Present study deals with the adsorption of Pb(II) from aqueous solution on rice husk ash. Rice husk is a by-product generally obtained from rice mill. Rice husk ash is a solid obtained after burning of rice husk. Batch studies were performed to evaluate the influences of various experimental parameters like pH, initial concentration, adsorbent dosage, contact time and the effect of temperature. Optimum conditions for Pb(II) removal were found to be pH 5, adsorbent dosage 5 g/L of solution and equilibrium time 1h. Adsorption of Pb(II) followed pseudo-second-order kinetics. The effective diffusion coefficient is of the order of 10(-10)m(2)/s. The equilibrium adsorption isotherm was better described by Freuindlich adsorption isotherm model. The adsorption capacity (q(max)) of rice husk ash for Pb(II) ions in terms of monolayer adsorption was 91.74 mg/g. The change of entropy (DeltaS(0)) and enthalpy (Delta H(0)) were estimated at 0.132 kJ/(mol K) and 28.923 kJ/mol respectively. The negative value of Gibbs free energy (Delta G(0)) indicates feasible and spontaneous adsorption of Pb(II) on rice husk ash. The value of the adsorption energy (E), calculated using Dubinin-Radushkevich isotherm, was 9.901 kJ/mol and it indicated that the adsorption process was chemical in nature. Application study was also carried out to find the suitability of the process in waste water treatment operation.     

Removal of copper ions by modified Unye clay, Turkey

This paper presents the adsorption of Cu(II) from aqueous solution on modified Unye bentonite. Adsorption of Cu(II) by manganase oxide modified bentonite (MMB) sample was investigated as a function of the initial Cu(II) concentration, solution pH, ionic strength, temperature and inorganic ligands (Cl(-), SO(4)(2-), HPO(4)(2-)). Changes in the surfaces and structure were characterized using X-ray diffraction (XRD), infrared (IR) spectroscopy, N(2) gas adsorption and potentiometric titration data. The adsorption properties of raw bentonite (RB) were further improved by modification with manganese oxide. Langmuir monolayer adsorption capacity of the MMB (105.38 mg/g) was found greater than that of the raw bentonite (42.41 mg/g). The spontaneity of the adsorption process is established by decrease in DeltaG which varied from -4.68 to -5.10 kJ mol(-1) in temperature range 303-313 K. The high performance exhibited by MMB was attributed to increased surface area and higher negative surface charge after modification.     

Removal of copper(II) and lead(II) from aqueous solution by manganese oxide coated sand I. Characterization and kinetic study

The preparation, characterization, and sorption properties for Cu(II) and Pb(II) of manganese oxide coated sand (MOCS) were investigated. A scanning electron microscope (SEM), X-ray diffraction spectrum (XRD) and BET analyses were used to observe the surface properties of the coated layer. An energy dispersive analysis of X-ray (EDAX) and X-ray photoelectron spectroscopy (XPS) were used for characterizing metal adsorption sites on the surface of MOCS. The quantity of manganese on MOCS was determined by means of acid digestion analysis. The adsorption experiments were carried out as a function of solution pH, adsorbent dose, ionic strength, contact time and temperature. Binding of Cu(II) and Pb(II) ions with MOCS was highly pH dependent with an increase in the extent of adsorption with the pH of the media investigated. After the Cu(II) and Pb(II) adsorption by MOCS, the pH in solution was decreased. Cu(II) and Pb(II) uptake were found to increase with the temperature. Further, the removal efficiency of Cu(II) and Pb(II) increased with increasing adsorbent dose and decreased with ionic strength. The pseudo-first-order kinetic model, pseudo-second-order kinetic model, intraparticle diffusion model and Elovich equation model were used to describe the kinetic data and the data constants were evaluated. The pseudo-second-order model was the best choice among all the kinetic models to describe the adsorption behavior of Cu(II) and Pb(II) onto MOCS, suggesting that the adsorption mechanism might be a chemisorption process. The activation energy of adsorption (E(a)) was determined as Cu(II) 4.98 kJ mol(-1) and Pb(II) 2.10 kJ mol(-1), respectively. The low value of E(a) shows that Cu(II) and Pb(II) adsorption process by MOCS may involve a non-activated chemical adsorption and a physical sorption.     

Biosorption of Pb(II) ions by modified quebracho tannin resin

In this study, the effect of temperature, pH and initial metal concentration on Pb(II) biosorption on modified quebracho tannin resin (QTR) was investigated. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to investigate QTR structure and morphology. Besides, the specific BET surface area and zeta-potential of the QTR were analysed. Thermodynamic functions, the change of free energy (DeltaG degrees), enthalpy (DeltaH degrees) and entropy (DeltaS degrees) of Pb adsorption on modified tannin resin were calculated as -5.43 kJ mol(-1) (at 296+/-2K), 31.84 kJ mol(-1) and 0.127 J mmol(-1) K(-1), respectively, indicating the spontaneous, endothermic and the increased randomness nature of Pb(2+) adsorption. The kinetic data was tested using pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion model. The results suggested that the pseudo-second-order model (R(2)>0.999) was the best choice among all the kinetic models to describe the adsorption behavior of Pb(II) onto QTR. Langmuir, Freundlich and Tempkin adsorption models were used to represent the equilibrium data. The best interpretation for the experimental data was given by the Langmuir isotherm and the maximum adsorption capacity (86.207 mg g(-1)) of Pb(II) was obtained at pH 5 and 296 K.     

Photocatalytic reduction of Cr(VI) on the new hetero-system CuAl2O4/TiO2

A magnetic adsorbent, amine-functionalized silica magnetite (NH(2)/SiO(2)/Fe(3)O(4)), has been synthesized to behave as an anionic or cationic adsorbent by adjusting the pH value of the aqueous solution to make amino groups protonic or neutral. NH(2)/SiO(2)/Fe(3)O(4) were used to adsorb copper ions (metal cation) and Reactive Black 5 (RB5, anionic dye) in an aqueous solution in a batch system, and the maximum adsorption were found to occur at pH 5.5 and 3.0, respectively. The adsorption equilibrium data were all fitted the Langmuir isotherm equation reasonably well, with a maximum adsorption capacity of 10.41 mg g(-1) for copper ions and of 217 m g g(-1) for RB5. A pseudo-second-order model also could best describe the adsorption kinetics, and the derived activation energy for copper ions and RB5 were 26.92 kJ mol(-1) and 12.06 kJ mol(-1), respectively. The optimum conditions to desorb cationic and anionic adsorbates from NH(2)/SiO(2)/Fe(3)O(4) were provided by a solution with 0.1M HNO(3) for copper ions and with 0.05 M NaOH for RB5.     

Adsorption characteristics of heavy metal ions onto a low cost biopolymeric sorbent from aqueous solutions

In this study, the adsorption conditions of Cu(II), Pb(II) and Cd(II) metal ions onto sporopollenin have been studied. The different variables effecting the sorption capacity such as pH of the solution, adsorption time, initial metal ion concentration and temperature have been investigated. Adsorption isotherms correlated well with the Freundlich type adsorption isotherm and adsorption capacities were found to be 0.0195, 0.0411 and 0.0146 mmol g(-1) for Cu(II), Pb(II) and Cd(II) metal ions, respectively. Experimental data were also evaluated to find out kinetic characteristics of the adsorption process. Adsorption processes for three target heavy metal ions were found to follow pseudo-second order type adsorption kinetics. Intraparticle diffusion was found to take part in adsorption processes but it could not be accepted as the primary rate-determining step. The mean free energies of adsorption (E) were found to be between 8 and 16 kJ mol(-1) for the metal ions studied and therefore adsorption mechanism for the adsorbent was explained as an ion-exchange process. But it was observed that chelating effect is also playing an important role in the adsorption of metal ions onto sporopollenin. Thermodynamic parameters, DeltaH degrees , DeltaS degrees and DeltaG degrees were also calculated from graphical interpretation of the experimental data. Standard heats of adsorption (DeltaH degrees ) were found to be endothermic and DeltaS degrees values were calculated to be positive for the adsorption of Cu(II), Pb(II) and Cd(II) ions onto the adsorbent. Negative DeltaG degrees values indicated that adsorption process for these three metal ions onto sporopollenin is spontaneous.     

Equilibrium, kinetic and thermodynamic studies of adsorption of Pb(II) from aqueous solution onto Turkish kaolinite clay

The adsorption of Pb(II) onto Turkish (Bandirma region) kaolinite clay was examined in aqueous solution with respect to the pH, adsorbent dosage, contact time, and temperature. The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and both models fitted well. The monolayer adsorption capacity was found as 31.75 mg/g at pH 5 and 20 degrees C. Dubinin-Radushkevich (D-R) isotherm model was also applied to the equilibrium data. The mean free energy of adsorption (13.78 kJ/mol) indicated that the adsorption of Pb(II) onto kaolinite clay may be carried out via chemical ion-exchange mechanism. Thermodynamic parameters, free energy (deltaG degrees ), enthalpy (deltaH degrees ) and entropy (deltaS degrees ) of adsorption were also calculated. These parameters showed that the adsorption of Pb(II) onto kaolinite clay was feasible, spontaneous and exothermic process in nature. Furthermore, the Lagergren-first-order, pseudo-second-order and the intraparticle diffusion models were used to describe the kinetic data. The experimental data fitted well the pseudo-second-order kinetics.     

Removal of Pb(II) ions from aqueous solutions by sulphuric acid-treated wheat bran

Sulphuric acid-treated wheat bran (STWB) was used as an adsorbent to remove Pb(II) ions from aqueous solution. It was observed that the adsorption yield of Pb(II) ions was found to be pH dependent. The equilibrium time for the process was determined as 2h. STWB gave the highest adsorption yield at around pH 6.0. At this pH, adsorption percentage for an initial Pb(II) ions concentration of 100mg/L was found to be 82.8 at 25 degrees C for contact time of 2h. The equilibrium data obtained at different temperatures fitted to the non-linear form of Langmuir, Freundlich and Redlich-Peterson and linear form of Langmuir and Freundlich models. Isotherm constants were calculated and compared for the models used. The maximum adsorption capacity (q(max)) which was obtained linear form of Langmuir model increased from 55.56 to 79.37mg/g with increasing temperature from 25 to 60 degrees C. Similar trend was observed for other isotherm constants related to the adsorption capacity. Linear form of Langmuir isotherm data was evaluated to determine the thermodynamic parameters for the process. Thermodynamic parameters show that adsorption process of Pb(II) ions is an endothermic and more effective process at high temperatures. The pseudo nth order kinetic model was successfully applied to the kinetic data and the order (n) of adsorption reaction was calculated at the range from 1.711 to 1.929. The values of k(ad) were found to be 5.82x10(-4) and 21.81x10(-4)(min(-1))(mg/g)(1-n) at 25 and 60 degrees C, respectively. Activation energy was determined as 29.65kJ/mol for the process. This suggest that the adsorption Pb(II) ions by STWB is chemically controlled.     

Sorption and desorption of lead (II) from wastewater by green algae Cladophora fascicularis

Biosorption is an effective method to remove heavy metals from wastewater. In this work, adsorption features of Cladophora fascicularis were investigated as a function of time, initial pH, initial Pb(II) concentrations, temperature and co-existing ions. Kinetics and equilibria were obtained from batch experiments. The biosorption kinetics followed the pseudo-second order model. Adsorption equilibria were well described by the Langmuir and Freundlich isotherm models. The maximum adsorption capacity was 198.5 mg/g at 298K and pH 5.0. The adsorption processes were endothermic and the biosorption heat was 29.6 kJ/mol. Desorption experiments indicated that 0.01 mol/L Na(2)EDTA was an efficient desorbent for the recovery of Pb(II) from biomass. IR spectrum analysis suggested amido or hydroxy, CO and C-O could combine intensively with Pb(II).     

Zn(II) adsorption from synthetic solution and kaolin wastewater onto vermicompost

The adsorption of Zn(II) from both synthetic solution and kaolin industry wastewater by cattle manure vermicompost was studied. The adsorption process was dependent on the various operating variables, viz., solution pH, particle size of the vermicompost, mass of vermicompost/volume of the Zn(II) solution ratio, contact time and temperature. The optimum conditions for Zn adsorption were pH 6.0, particle size of < or = 250 microm, 1 g per 10 mL adsorbent dose, contact time of 4h and temperature of 25 degrees C. Langmuir and Freundlich adsorption isotherms fit well in the experimental data and their constants were evaluated, with R(2) values from 0.95 to 0.99. In synthetic solution, the maximum adsorption capacity of the vermicompost for Zn(2+) ions was 20.48 mg g(-1) at 25 degrees C when the vermicompost dose was 1 g 10 mL(-1) and the initial adjusted pH was 2. The batch adsorption studies of Zn(II) on vermicompost using kaolin wastewater have shown the maximum adsorption capacity was 2.49 mg g(-1) at pH 2 (natural pH of the wastewater). The small values of the constant related to the energy of adsorption (from 0.07 to 0.163 L mg(-1)) indicated that Zn(2+) ions were binded strongly to vermicompost. The values of the separation factor, R(L), which has been used to predict affinity between adsorbate and adsorbent were between 0 and 1, indicating that sorption was very favorable for Zn(II) in synthetic solution and kaolin wastewater. The thermodynamic parameter, the Gibbs free energy, was calculated for each system and the negative values obtained confirm that the adsorption processes are spontaneous. The DeltaG degrees values were -19.656 kJ mol(-1) and -16.849 kJ mol(-1) for Zn(II) adsorption on vermicompost in synthetic solution at pH 6 and 2, respectively, and -13.275 kJ mol(-1) in kaolin wastewater at pH 2.     

Investigation of a basic dye removal from aqueous solution onto chemically modified Unye bentonite

The adsorption behavior of crystal violet (CV⁺) from aqueous solution onto magnesium-oxide coated bentonite (MCB) sample was investigated as a function of parameters such as initial CV⁺ concentration, contact time and temperature. The Langmuir, and Freundlich adsorption models were applied to describe the equilibrium isotherms. The Langmuir monolayer adsorption capacity of MCB were estimated as 496 mg/g. The pseudo-first-order, pseudo-second-order kinetic and the intra-particle diffusion models were used to describe the kinetic data and rate constants were evaluated. The values of the energy (E_a), enthalpy (ΔH^≠) and entropy of activation (ΔS^≠) were 56.45 kJ/mol, 53.90 kJ/mol and −117.26 J/mol K, respectively, at pH 6.5.     

Removal of Pb(II) from aqueous solution on chitosan/TiO(2) hybrid film

This paper presents the adsorption of Pb(II) from aqueous solution using chitosan/TiO(2) hybrid film (CTF) adsorbent. Batch experiments were carried out as a function of solution pH, adsorption time, Pb(II) concentration and temperature. The equilibrium data fitted well with the linear Freundlich model. The adsorption process was proved to be the second grade reaction and the theoretically maximum adsorption amount at equilibrium was 36.8 mg-Pb/g. The influence parameters were optimized by response surface method (RSM), such as initial metal concentration, pH and temperature. The extreme points were gained by the Statistical Analysis System software: initial metal concentration is 50-55 mg/l, pH is 3-4 and temperature is 60 degrees C. Very high regression coefficient (R(2)=0.9689) indicates excellent evaluation of experimental data by second-order polynomial regression model. Under this condition the theoretical adsorption efficiency is 90.6%. It illuminates that this model is reliable to optimize the adsorption process and CTF is suitable for adsorbing Pb(II) from aqueous solution.     

Biosorption of Pb(II) and Cd(II) from aqueous solution using green alga (Ulva lactuca) biomass

The biosorption characteristics of Pb(II) and Cd(II) ions from aqueous solution using the green alga (Ulva lactuca) biomass were investigated as a function of pH, biomass dosage, contact time, and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of the metal ions by U. lactuca biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The monolayer biosorption capacity of U. lactuca biomass for Pb(II) and Cd(II) ions was found to be 34.7mg/g and 29.2mg/g, respectively. From the D-R isotherm model, the mean free energy was calculated as 10.4kJ/mol for Pb(II) biosorption and 9.6kJ/mol for Cd(II) biosorption, indicating that the biosorption of both metal ions was taken place by chemisorption. The calculated thermodynamic parameters (DeltaG degrees , DeltaH degrees and DeltaS degrees ) showed that the biosorption of Pb(II) and Cd(II) ions onto U. lactuca biomass was feasible, spontaneous and exothermic under examined conditions. Experimental data were also tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. The results showed that the biosorption processes of both metal ions followed well pseudo-second-order kinetics.     

The adsorption kinetics and removal of cationic dye, Toluidine Blue O, from aqueous solution with Turkish zeolite

Clinoptilolite, a natural zeolite, was investigated as an inexpensive and effective adsorbent for the adsorption of Toluidine Blue O (TBO) from its aqueous solution. The effect of parameters such as the initial concentration of TBO, the solution of pH, contact time, temperature and particle size on the TBO adsorption was examined. The adsorption rate data were analysed according to the first and second-order kinetic models. Kinetic studies show that adsorption of TBO on clinoptilolite was fitted to the second-order adsorption model with two-step diffusion process. The activation energies for TBO adsorption on clinoptilolite for the first and second diffusion processes were 8.72 kJ mol(-1) and 19.02 kJ mol(-1), respectively. The adsorption isotherm was well fitted to both the Langmuir and Freundlich models. The maximum adsorption capacity of clinoptilolite for TBO was 2.1x10(-4) mol g(-1) at solution pH of 11.0.     

硫脲改性Fe_3O_4/壳聚糖微球对Hg~(2+)的吸附性能

利用反相悬浮分散法制备Fe3O4/壳聚糖磁性微球,并经硫脲改性(TMCS)用于吸附水溶液中Hg2+。考察了pH值、温度的影响,以及吸附动力学和吸附等温线。结果表明,TMCS为球形,粒径80μm～250μm。TMCS对Hg2+的吸附量随pH值升高而增加,但随温度升高而下降;焓变(ΔH0=-12.93kJ/mol)为负,表明吸附放热;Gibbs自由能(ΔG0=-16.41kJ/mol～-17.22kJ/mol)为负,表明吸附能自发进行。等温吸附线可用Langmuir模型拟合,最大吸附容量2.69mmol/g;吸附动力学可用拟二级模型拟合,表明化学吸附为控速步骤。吸附Hg2+后的TMCS可用0.01mol/L的EDTA脱附,脱附率达91%。     

Clarified sludge (basic oxygen furnace sludge) – an adsorbent for removal of Pb(II) from aqueous solutions – kinetics, thermodynamics and desorption studies

The basic oxygen furnace waste generated in steel plant has been used as a low cost adsorbent for the removal of Pb(II) from aqueous solution. The effect of pH, adsorbent dosage, initial metal ion concentration, contact time and temperature on adsorption process was studied in batch experiments. Results of the equilibrium experiments showed that the solution pH was the key factor affecting the adsorption characteristics. Optimum pH for the adsorption was found to be 5 with corresponding adsorbent dosage level of 5 g/L. The equilibrium was achieved within 1 h of contact time. Kinetics data were best described by pseudo second order model. The effective particle diffusion coefficient of Pb(II) is the order of 10⁻¹⁰ m²/s. The maximum uptake was 92.5 mg/g. The adsorption data can be well fitted by Freundlich isotherm. The result of the equilibrium studies showed that the solution pH was the key factor affecting the adsorption. External mass transfer analysis was also carried out for the adsorption process. The thermodynamic studies indicated that the adsorption is spontaneous and endothermic. The sorption energy (10.1745 kJ/mol) calculated from Dubinin–Radushkevich isotherm indicated that the adsorption process is chemical in nature. Desorption studies were carried out using dilute mineral acids to elucidate the mechanism of adsorption. Application studies were carried out considering the economic viewpoint of wastewater treatment plant operations.     

Removal of methylene blue from aqueous solution with silica nano-sheets derived from vermiculite

The adsorption kinetics of a cationic dye, methylene blue (MB), onto the silica nano-sheets derived from vermiculite via acid leaching was investigated in aqueous solution in a batch system with respect to contact time, initial dye concentration, pH, and temperature. Experimental results have shown that increasing initial dye concentration favors the adsorption while the acidic pH and temperature go against the adsorption. Experimental data related to the adsorption of MB on the silica nano-sheets under different conditions were applied to the pseudo-first-order equation, the pseudo-second-order equation and the intraparticle diffusion equation, and the rate constants of first-order adsorption (k(1)), the rate constants of second-order adsorption (k(2)) and intraparticle diffusion rate constants (k(int)) were calculated, respectively. The experimental data fitted very well the pseudo-second-order kinetic model. The activation energy of system (E(a)) was calculated as 3.42 kJ/mol. The thermodynamics parameters of activation such as Gibbs free energy, enthalpy, entropy were also evaluated and found that DeltaG*, DeltaH*, and DeltaS* are 65.95 (71.63, 77.45)kJ/mol, 0.984 (0.776, 0.568)kJ/mol, and -0.222 (-0.223, -0.224)kJ/(Kmol) at 20 (45, 70) degrees C, respectively. The desorption of the dye on the silica nano-sheets using ethanol was also investigated primarily.