Surface Modifications of Superparamagnetic Iron Oxide Nanoparticles with Polyvinyl Alcohol, Chitosan, and Graphene Oxide as Methylene Blue Adsorbents

Abstract

Synthetic dye contamination of wastewater has long been a social issue, with adsorption being the most focused upon research technique among wastewater treatment. Using the co-precipitation method, superparamagnetic iron oxide nanoparticles (SPIONs) with the size of 13.6 ± 1.9 nm were synthesized. By adsorbing methylene blue (MB) on the modified surface of SPIONs using polyvinyl alcohol, chitosan, and graphene oxide, the entrapment efficiency at pH 7 can be up to 87.00 ± 0.16% after 13 days, and the highest MB loading capacity was 3.638 ± 0.009%, while the highest loading amount achieved was 36.385 ± 0.095 mg/g. The cumulative desorption capacity of the adsorbent at pH 3.8 was at its maximum at 8.94 ± 0.66% after 30 days. The results of the experiments indicated that the compound has a favorable impact on the adsorption of synthetic dyes; nevertheless, more research is needed to determine the ideal ratio, temperature, and pH levels for this chemical.

Surface Modifications of Superparamagnetic Iron Oxide Nanoparticles with Polyvinyl Alcohol and Graphite as Methylene Blue Adsorbents

“…The adsorption isotherm can be calculated by applying the Langmuir isotherm (Equations ( 5)-( 8)) [27,28] the Freundlich isotherm (Equations ( 9) and ( 10)) [29], the Dubinin-Radushkevich (D-R) isotherm (Equation ( 10)) [28], the Temkin and Pyzhev isotherm (Equations ( 12)-( 14)) [30,31] and the Halsey isotherm (Equation ( 15)) model [32].…”

Surface Modifications of Superparamagnetic Iron Oxide Nanoparticles with Polyvinyl Alcohol, Chitosan, and Activated Carbon or Graphite as Methylene Blue Adsorbents—Comparative Study

“…There are several approaches to treating dye effluents, including adsorption, ion exchange, flocculation, decantation, advanced oxidation processes, biodegradation, chemical precipitation, and other processes [6]. Among all of these techniques, adsorption has gained popularity for being an attractive option since, depending on the system, it is efficient, cost-effective, and simple to handle materials [7].…”

“…Nevertheless, several investigations have demonstrated that some undesired SPION aggregates may have lower stability, biocompatibility, and effectiveness. As a result, the use of SPION in conjunction with other stabilizing tools, such as carbon compounds, has been researched [6,10,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31].…”

“…Without any modifications, SPION has an adsorption capacity of 45.43 mg/mL at pH = 12 and T = 298 K [20]. By changing to pH = 7 and adding polymer and GO, the adsorption of SPION/PVA/CS/GO decreased slightly, to approximately 37 mg/mL [6]. In addition, there were some positive results with some of the products, such as the combination product SPION@Carbon sheets, which increased to 95 mg/g at very high temperatures, such as 400 • C, or SPION/EG modeled by Redlich-Peterson and PSO, which exhibited an adsorption value of 75 mg/mL compared to pure SPION [21][22][23][24].…”

“…Hence, the current work evaluates the potential for MB adsorption and desorption onto SPIONbased composites employing polymer blends and carbon-based materials. Therefore, the SPION/PVA/CS/AC and SPION/PVA/CS/GR were synthesized, and the MB adsorption/desorption capabilities were investigated and compared to the SPION/PVA/CS/GO, SPION/PVA/GR, and SPION/PVA/AC, which were previously published [6,17,31].…”