Investigation of the Efficiency of (Fe3O4@Sio2-MPAP) Magnetic Nanoparticles for the Removal of Anionic Dye from Aqueous Solutions: Kinetic, Isotherm and Thermodynamic Studies

Removal of reactive azo dyes has been recognized as one of the major problems in textile wastewater treatment process. In recent years, the use of nanoparticles has been very considered for the removal and reduction of contaminants in aquatic environments. In this survey, after synthesis of magnetic nanoparticles with a functional group of ester, their efficiency was investigated to remove the Reactive Black 5 (RB 5) dye from aqueous solutions. The synthesis of magnetic silica-ester nanoparticles was carried out with co-precipitation method in alkaline conditions. TEM analysis was used to identify the nanoparticles size. The effect of independent variables of pH, initial concentration of dye and amount of nanoparticles on dye removal efficiency were evaluated. Kinetic, isotherm and thermodynamic analysis were implemented for determining the mechanism and rate of absorption. Finally the efficiency of recycled nanoparticles to remove the RB 5 dye was investigated. Findings: The results showed that 100% of the dye was removed at pH = 2 , dye concentration 20 mg/l and 0.3 g/l of silica-ester nanoabsorbent during 80 min. Kinetic studies of RB 5 removal in the optimal conditions demonstrated that the Pseudo-second-order equation kinetic model correspond to the adsorption process, and also represent the chemical absorption procedure. The absorption equilibrium data were in good agreement with the Langmuir isotherm model. Thermodynamic studies showed that the process of dye absorption was feasible, spontaneous and endothermic. The synthesized nano-adsorbents had five-fold suitable recycle efficiency. According to the results, the silica-ester nanoparticles have been shown to be effective in removing RB 5 dye from aqueous solutionand these nanoparticles due to proper recycling capability and chemical stretcher can be noticed as an active absorbent for other anionic dyes.