The potentials of silty clay(SC),acquired from Chaman,Balochistan,were investigated as adsorbent for Ni(Ⅱ)and Cd(Ⅱ)removal from contaminated media.The influence of different operating factors like dose,pH,temperatur...The potentials of silty clay(SC),acquired from Chaman,Balochistan,were investigated as adsorbent for Ni(Ⅱ)and Cd(Ⅱ)removal from contaminated media.The influence of different operating factors like dose,pH,temperature,and time of contact was explored,and optimum values were noted under batch adsorption method.Isothermal study was conducted with varying concentrations of solutions on optimized conditions and different adsorption models i.e.,Langmuir,Freundlich,Temkin and Dubinin-Radushkevich(D-R)isotherm,which were employed to interpret the process.The isothermal data of both Ni(Ⅱ)and Cd(Ⅱ)were well fitted to Langmuir isotherm suggesting the formation of monolayer of metal ions on silty clay.The values of adsorption capacity noted for Ni(Ⅱ)and Cd(Ⅱ)were 3.603 mg·g^-1 and 5.480 mg·g^-1,respectively.Kinetic studies affirmed that pseudo second order(PSO)kinetics was being obeyed by the removal of Ni(Ⅱ)and Cd(Ⅱ).Thermodynamic variables like free energy change(ΔG°),enthalpy change(ΔH°)and entropy change(ΔS°)were calculated.The negative value ofΔG°and the positive values ofΔH°andΔS°unfolded that the removal process of both metal ions of by SC was spontaneous,endothermic and feasible.展开更多
The aim of the study was to synthesize zinc oxide nanoparticles(ZnONPs)composite with clay by a novel route and then to explore the capability of composite of ZnONPs and silty clay(SC)as adsorbents for Pb(II)eradicati...The aim of the study was to synthesize zinc oxide nanoparticles(ZnONPs)composite with clay by a novel route and then to explore the capability of composite of ZnONPs and silty clay(SC)as adsorbents for Pb(II)eradication from aqueous media by batch adsorption method.The effect of different operating factors like temperature,pH,dose and time of contact on the adsorption process were studied to optimize the conditions.Langmuir,Freundlich,Dubinin-Radushkevich(DR)and Temkin isotherms were applied for the interpretation of the process.The R^(2)and q values obtained from Langmuir model suggested that the process is best interpreted by this model.The values of adsorption capacity(qm)noted were 12.43 mg·g^(-1) and 14.54 mg·g^(-1)on SC and ZnONPsSC respectively.The kinetic studies exposed that pseudo second order(PSO)kinetics is followed by the processes suggesting that more than one steps are involved to control the rate of reactions.Various thermodynamic variables such as change in free energy(AGe),change in enthalpy(AH9)and change in entropy(ASe)were calculated.Thermodynamic data suggested that Pb(II)adsorption on SC and ZnONPsSC are spontaneous,endothermic and feasible processes.展开更多
文摘The potentials of silty clay(SC),acquired from Chaman,Balochistan,were investigated as adsorbent for Ni(Ⅱ)and Cd(Ⅱ)removal from contaminated media.The influence of different operating factors like dose,pH,temperature,and time of contact was explored,and optimum values were noted under batch adsorption method.Isothermal study was conducted with varying concentrations of solutions on optimized conditions and different adsorption models i.e.,Langmuir,Freundlich,Temkin and Dubinin-Radushkevich(D-R)isotherm,which were employed to interpret the process.The isothermal data of both Ni(Ⅱ)and Cd(Ⅱ)were well fitted to Langmuir isotherm suggesting the formation of monolayer of metal ions on silty clay.The values of adsorption capacity noted for Ni(Ⅱ)and Cd(Ⅱ)were 3.603 mg·g^-1 and 5.480 mg·g^-1,respectively.Kinetic studies affirmed that pseudo second order(PSO)kinetics was being obeyed by the removal of Ni(Ⅱ)and Cd(Ⅱ).Thermodynamic variables like free energy change(ΔG°),enthalpy change(ΔH°)and entropy change(ΔS°)were calculated.The negative value ofΔG°and the positive values ofΔH°andΔS°unfolded that the removal process of both metal ions of by SC was spontaneous,endothermic and feasible.
文摘The aim of the study was to synthesize zinc oxide nanoparticles(ZnONPs)composite with clay by a novel route and then to explore the capability of composite of ZnONPs and silty clay(SC)as adsorbents for Pb(II)eradication from aqueous media by batch adsorption method.The effect of different operating factors like temperature,pH,dose and time of contact on the adsorption process were studied to optimize the conditions.Langmuir,Freundlich,Dubinin-Radushkevich(DR)and Temkin isotherms were applied for the interpretation of the process.The R^(2)and q values obtained from Langmuir model suggested that the process is best interpreted by this model.The values of adsorption capacity(qm)noted were 12.43 mg·g^(-1) and 14.54 mg·g^(-1)on SC and ZnONPsSC respectively.The kinetic studies exposed that pseudo second order(PSO)kinetics is followed by the processes suggesting that more than one steps are involved to control the rate of reactions.Various thermodynamic variables such as change in free energy(AGe),change in enthalpy(AH9)and change in entropy(ASe)were calculated.Thermodynamic data suggested that Pb(II)adsorption on SC and ZnONPsSC are spontaneous,endothermic and feasible processes.
