Investigation of performance of bimodal/functionalized mesoprorous silica nanoparticles on the adsorption of methylene blue from aqueous solution

Subject Areas : Journal of Nanoanalysis

Shahnaz  Nayyeri ¹ (Faculty of chemistry, Amirkabir University of Technology, Tehran, Iran)
Amir  Vahid ² (Downstream Devision, Research institute of petroleum industry, Tehran, Iran)
Majid  Abdous ³ (Faculty of chemistry, Amirkabir University of Technology, Tehran, Iran)
Aliakbar  Miran Beigi ⁴ (Research institute of petroleum industry, Tehran, Iran)

Received: 2017-07-22 Accepted : 2017-07-22 Published : 2018-03-01

Keywords: Adsorption, Isotherm, Methylene Blue, Mesoporous silica, Wastewater treatment,

Abstract :

In this study, bimodal mesoporous silica, i.e. UVM-7, was synthesized and functionalized withsulfonic acid and characterized using XRD, nitrogen physisorption, SEM, TEM and acid/basetitration. The results displayed that bimodal mesopore structure was firmly formed and acidicfunctional groups were grafted on the surface of the UVM-7. The concentration of the acidicfunctional groups was determined via titration by the standard NaOH solution. At the secondstep, the adsorption of methylene blue from aqueous solutions onto UVM-7 and UVM-7/SO3H was investigated. The effect of PH, temperature, dye concentration, salt concentrationand contact time on the adsorption of methylene blue was studied. The adsorption equilibriumisotherms were well fitted to Langmuir rather than Freundlich model. Methylene blueadsorption on UVM-7 increases with increasing the temperature and PH, which indicatesthat the process is endothermic. Maximum adsorption capacity of methylene blue by UVM-7and UVM-7/SO3H were 107.5 mg/g and 129.9 mg/g, respectively. The adsorption kinetics ofmethylene blue for both UVM-7 and UVM-SO3H were pseudo-second order and well fitted toLangmuir model.