Adsorption characteristics of methyl blue onto magnetic Mn_0.5Co_0.5Fe₂O₄ nanoparticles prepared via a rapid combustion process

Abstract

A rapid combustion process for the preparation of magnetic Mn0.5Co0.5Fe2O4 nanoparticles was introduced, which was composed of the preparation process of solution, combustion process and calcination process. The structure and properties of the as‐prepared product were investigated by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometer. The results revealed that the volume of absolute alcohol and the calcination temperature were two key parameters for the preparation of Mn0.5Co0.5Fe2O4 nanoparticles. With the volume of absolute alcohol increasing from 15 to 100 mL, the particle size of Mn0.5Co0.5Fe2O4 nanoparticles calcined at 400°C for 2 h increased from 18 to 25 nm, and the saturation magnetization increased from 3.4 to 66.3 Am2/kg; while with the calcination temperature increasing from 400 to 700°C with 20 mL absolute alcohol, the particle size increased from 20 nm to 47 nm, the saturation magnetizations increased from 13.1 to 66.0 Am2/kg, and the specific surface area decreased from 102.99 to 0.13 m2/g. The adsorption characteristics of methyl blue (MB) onto Mn0.5Co0.5Fe2O4 nanoparticles at room temperature were investigated, and the regression equation was found in good agreement with the pseudo‐second‐order adsorption kinetics model with the initial MB concentrations of 50–200 mg/L; the adsorption equilibrium data of MB onto Mn0.5Co0.5Fe2O4 nanoparticles at room temperature were analyzed with Langmuir, Freundlich and Temkin models, and the adsorption isotherm was most effectively described by the Temkin model based on the value of the correlation coefficient (0.9931); the effect of pH on the adsorption of MB was examined, and the reusability of Mn0.5Co0.5Fe2O4 nanoparticles for adsorbing of MB revealed their excellent removal efficiency. © 2018 American Institute of Chemical Engineers Environ Prog, 38: S277–S287, 2019

Equilibrium, kinetic, and thermodynamic studies of new materials based on xanthan gum and cobalt ferrite for dye adsorption

“…[59 The Freundlich model is an empirical equation that assumes the heterogeneous surface of the adsorbent, on which the adsorbed molecules are interactive. [53] The linear form of the Freundlich isotherm is expressed as Equation ( 11) by plotting log C e versus log q e [58] : where K F and n are the Freundlich adsorption isotherm constants. Both can be determined from the intercept and the slope of the linear plot, and indicate the extent of the adsorption and the degree of nonlinearity between the dye solution concentration and the adsorption respectively.…”

“…where K J (L g À1 ) is the parameter of the Javanovic model. [52] Ni 0.5 Zn 0.5 Fe 2 O 4 NPs Methyl Blue 54.70 Liu et al [53] Polyethersulfone/GO Methyl Blue 62.50 Zhang et al [54] XGCF [55] Bottom ash Basic Fuchsine 6.40 Gupta et al [55] CoVP Basic Fuchsine 32.63 Nistor et al [56] XGCF The graphic representation of the isotherm models is shown in Figures S6 and S7. For the Freundlich, Temkin, and Javanovic isotherms models, R 2 presents low values and the specific determined parameters (k F , k T , and q max J ) do not correlate with the experimental data.…”

Adsorption performance of magnetic Mg0.5Ni0.5Fe2O4 nanoparticles for reactive red 2BF

“…The Langmuir model assumes that the adsorption of the adsorbate on the adsorbent is a monolayer, its adsorption capacity depends on the occupation rate of the active sites on the adsorbent surface, and the interface energy is uniform [29]. However, the Freundlich model assumes that the adsorption of adsorbate on the adsorbent is heterogeneous, the active sites are first occupied, and then the binding energy decreases with an increase in the number of occupied sites [10]. Whereas the Temkin model considers the adsorbent and the q e and q t were the qualities of adsorbed RR-2BF at equilibrium and a sampling time (mg•g −1 ), respectively [10]; k 1 (min −1 ), k 2 (g•mg −1 •min −1 ), and k i (mg•g −1 •min −1 ) were the rate constants [29]; and x i was associated to the thickness of the boundary layer.…”

“…However, the Freundlich model assumes that the adsorption of adsorbate on the adsorbent is heterogeneous, the active sites are first occupied, and then the binding energy decreases with an increase in the number of occupied sites [10]. Whereas the Temkin model considers the adsorbent and the q e and q t were the qualities of adsorbed RR-2BF at equilibrium and a sampling time (mg•g −1 ), respectively [10]; k 1 (min −1 ), k 2 (g•mg −1 •min −1 ), and k i (mg•g −1 •min −1 ) were the rate constants [29]; and x i was associated to the thickness of the boundary layer. adsorbate to interact, and the adsorption heat linearly decreases with an increase in the coverage [31], the binding energy is uniformly distributed, and it increases to a maximum binding energy.…”

“…The adsorption method is considered the most effective owing to thorough-paced removal, low cost, and no secondary pollution [8,9]. In this method, the key factor is the adsorbent selected [10]. Activated carbon is an ideal adsorbent owing to its high adsorption capacity [11].…”