Sustainable Synthesis of Iron–Zinc Nanocomposites by Azadirachta indica Leaves Extract for RSM-Optimized Sono-Adsorptive Removal of Crystal Violet Dye

Abstract

Environmental pollution has exacerbated the availability of clean water to mankind. In this study, Azadirachta indica leaf extract was used for sustainable synthesis of Fe–Zn nanocomposites (IZNC). The instrumental techniques of Fourier transformed infrared (FTIR) spectroscopy, energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) were used to determine the structural and chemical composition. The overall surface was mildly acidic in nature, as the pHPZC was observed to be 6.00. The ultrasonicated adsorption experiments were designed by central composite design (CCD). The best responses, which proposed a contaminants removal of 80.39%, were assessed using the response surface methodology (RSM). By repeating experimental runs at the expected optimum operating parameters (OOP), the method was experimentally affirmed with the %mean error and %RSD9 being 2.695% and 1.648%, respectively. The interaction of CV dye and the nanocomposite showed tremendous adsorption efficiency towards crystal violet (CV) dye, as revealed by isotherm studies. Fitting kinetics and isotherm models were affirmed by root mean square error (RMSE), χ2, and a Pearson regression coefficient. Thermodynamic studies proved spontaneity of the CV dye adsorption over the nanocomposites. The values for ΔGo, ΔHo, and ΔSo were observed to be −1.089 kJ/mol, 28.59 kJ/mol, and −3.546 kJ/mol, respectively. Recovery of CV dye was carried out in a variety of media, including NaOH, NaCl, and CH3COOH. The maximum CV recovery was achieved in an acidic media. The robustness of adsorption was affirmed by the interference of various matrix ions, including KCl, LiCl, NaCl, and MgCl2, which did not significantly affect the adsorption process. The maximum adsorption capacity was obtained at a low concentration of LiCl. The results show that a green synthesis approach for nanocomposite synthesis might be an effective and economical way to remove organic contaminants from wastewater. Moreover, it is also effective for effluent treatment plants (ETP) for waste management purposes, in which it may be coupled with chlorine as a disinfectant to purify water that can be used for domestic and irrigation purposes.

Capability of TiO2 and Fe3O4 nanoparticles loaded onto Algae (Scendesmus sp.) as a novel bio-magnetic photocatalyst to degration of Red195 dye in the sonophotocatalytic treatment process under ultrasonic/UVA irradiation

“…Figure 4 a was constructed from a comparison of predicted values against factual values 41 . The validity of the model was confirmed by a straight trend line connecting residuals (Fig.…”

Polyvinyl Alcohol Assisted Iron–Zinc Nanocomposite for Enhanced Optimized Rapid Removal of Malachite Green Dye

“…Additionally, a large, irregular tip at 1637.56 cm −1 displays the mild twisting of the N-H group, whereas a tiny crest at 1384.89 cm −1 displays the curving of the (phenolic) OH group. Additionally, because of the significant broadening of the M-O-C bond, two peaks in the area of 1100 cm −1 namely, 1097.5 cm −1 and 1136.07 cm −1 can be observed [31,36].…”

“…Additionally, a large, irregular tip at 1637.56 cm −1 displays the mild twisting of the N-H group, whereas a tiny crest at 1384.89 cm −1 displays the curving of the (phenolic) OH group. Additionally, because of the significant broadening of the M-O-C bond, two peaks in the area of 1100 cm −1 namely, 1097.5 cm −1 and 1136.07 cm −1 can be observed [31,36]. The SEM image of Fe-Zn-PVA NCs is shown in Figure 4a; the nanocomposites are between 80 to 100 nm in size and have spherical surfaces, which makes it easier for the dye to adhere to the Fe-Zn-PVA NCs.…”

The Statistical Error Optimization of Dye Sorption Equilibria for the Precise Prediction of Adsorption Isotherms on Activated Graphene

“…Over the years, due to its low cost, straightforward operation, and effective remediation of pollutants, the adsorption process has been established as a well-recognized pollutant remediation technique. It has been widely used in various industries [14][15][16].…”