An enhanced method for the removal of methyl violet dye using magnetite nanoparticles as an adsorbent: Isotherm, kinetic and thermodynamic study.

Abstract

A green method has been developed using Gilloy (Tinospora Cordifolia) shoot extract to synthesize magnetic nanoparticles (MNPs). A further modification of MNPs was performed using anionic surfactant sodium dodecyl sulphate (SDS), to remove cationic dye methyl violet (MV) efficiently from the solution. As an adsorbent, SDS modified MNPs (SDS-MNPs) were tested for their ability to remove MV dye. Synthesized MNPs were characterized by ultra violet-visible spectroscopy (UV-VIS), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). In batch adsorption experiments, the effect of adsorbent dosage, initial dye concentration, time, and pH was evaluated. The maximum adsorption capacity of the adsorbent for MV dye was found to be 174.2 mg g-1. The adsorption of dye onto the adsorbent followed Langmuir's isotherm. It was shown that the adsorption kinetics of dyes obeyed pseudo-second-order kinetics. Using thermodynamic parameters, spontaneous and exothermic adsorption was determined. As synthesized nanoparticles are magnetic in nature, regeneration and reusability of MNPs were investigated.