Remediation of toluidine blue O dye from aqueous solution using surface functionalized magnetite nanoparticles

Abstract

In the current study, tannic acid-functionalized iron oxide nanoparticles have been synthesized using a cost-effective co-precipitation method and subsequently characterized using various instrumentation techniques such as Fourier transform infrared spectroscopy, X-ray diffractometer, field emission scanning electron microscopy, and thermal gravimetric analysis. Further, these surface-modified magnetite nanoparticles have been used for the adsorption of toluidine dye from an aqueous solution. The adsorption process was accompanied using batch procedure, and influences of several factors such as adsorbent dose, contact time, pH, temperature, and initial concentration of adsorbate were inspected concurrently. The maximum adsorption capacity of tannic acid-functionalized magnetite nanoparticles was found to be 50.68 mg/g. The adsorption process was observed to follow the Temkin isotherm model, whereas the kinetic study was well described by pseudo-second order. The thermodynamic study revealed the adsorption process to be endothermic and spontaneous in nature with a high degree of freedom between adsorbent and adsorbate. Therefore, the study indicated that the tannic acid-functionalized magnetite nanoparticles have promising adsorption capability and can be used as an excellent adsorbent for the removal of toluidine blue O dye from the aqueous solution. HIGHLIGHTS Tannic acid-tailored magnetite nanoparticles were employed as adsorbents for the removal of coloured pollutants from an aqueous solution.; Batch adsorption techniques were applied to scrutinize the adsorption behaviour of these magnetite nanoparticles.; The adsorption process obeys pseudo-second-order kinetics and the Langmuir model of isotherm.; The desorption study suggested the reusability of adsorbents.;

Keywords

• adsorption
• magnetite nanoparticles
• surface functionalization
• tannic acid
• toluidine blue o