Preparation and characterization of magnetic CaFe2O4 nanoparticles for efficient adsorption of toxic Congo Red dye from aqueous solution: predictive modeling by artificial neural network

Abstract

a b s t r ac tIn this study, the performance and effectiveness of magnetic CaFe 2 O 4 nanoparticles prepared by simple chemical route were evaluated for the adsorption of toxic azo dye Congo Red (CR) from aqua matrix. The prepared CaFe 2 O 4 nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometer, point of zero charge, and Brunauer-Emmett-Teller surface area measurements. Batch mode adsorption experiments were performed to study the effect of various experimental parameters namely solution pH (4.0-10.0), contact time (2-120 min), adsorbent dose (0.25-1.5 g/L), and initial CR dye concentration (20-150 mg/L) on the adsorption process. Maximum CR dye removal of 99.01% was achieved at solution pH 4.0 and maximum adsorption capacity of 241.16 mg/g was reported at optimum experimental condition. The adsorption equilibrium data strictly follows Langmuir isotherm model and adsorption kinetics was well described by pseudo-second-order model. A three layered artificial neural network (ANN) was applied for the accurate prediction of percentage of CR dye removal by the CaFe 2 O 4 nanoparticles. The Levenberg-Marquardt backpropagation algorithm with "tansig" and "purelin" transfer function in hidden and output layer was used for model development. Optimal ANN architecture (4-9-1) shows high R 2 value (R 2 : 0.995) and very low mean squared error value (0.00042866), confirming the accurate prediction ability of CR dye removal efficiency in this adsorption process.

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“…The absorption peaks from 716 to 1068 cm -1 are assigned to the vibration of NO3 -group [27]. The observed peak at 1436 cm -1 could be attributed to C-H bending vibration [35]. In addition, the broad absorption band at 3433 cm -1 could be assigned to stretching vibration of O-H [27].…”

“…At the present study, three different solution temperatures (25,35 and 45 °C) were selected to investigate their effect on the adsorption behaviour of MB onto CFZ NPs. Besides, the other adsorption experimental conditions were fixed at the optimized values (pH value of 7, initial MB concentrations of 10 mg/L, adsorbent dosage of 0.01 g/20 mL and contact time of 90 min).…”

Ultrasound‐assisted enhanced and rapid uptake of anionic dyes from the binary system onto MnFe2O4/polyaniline nanocomposite at neutral pH

“…Therefore, it can be concluded that the reported methodology for sono-assisted adsorption of MR and CR dyes by MnF-PANI-NC is a superior method compared to many other reported methods on account of neutral solution pH conditions, quick attainment of equilibrium, and higher or comparable adsorption capacity of MnF-PANI-NC. [5,31,[37][38][39][40][41][42] 3.8 | Regeneration study of MnF-PANI-NC…”

Adsorptive Removal of Methylene Blue Dye from Aqueous Solutions Using CoFe1.9Mo0.1O4 Magnetic Nanoparticles

“…In contrast to the %R of MB, the qe value increased significantly from 4.89 to 19.12 mg/g as the initial dye concentration was increased from 50 to 250 mg/L, as shown in Figure 6. This can be explained by the fact that, at a fixed adsorbent dose, the high initial concentration of the dye will provide the required driving to transfer the MB molecules from the bulk liquid phase to the surface of solid adsorbent [8,41,42]. In addition, the increase in the value of Figure 5.…”