Magnetically responsive chitosan-based nanoparticles for remediation of anionic dyes: Adsorption and magnetically triggered desorption

Chitosan-based nanoparticles (PGMA/mCHT) were prepared for the adsorption of anionic Reactive Red 120 (RR120) and Indigo Carmine (IC). The morphology and characteristics were clarified by using SEM-EDX, XRD, VSM, and FTIR. The adsorption of RR120 and IC on PGMA/mCHT was carried out in a batch process to determine the influence of initial dye concentration (5-600 mg/L), initial pH (3-9), temperature (5, 25, 35, and 45 degrees C) and contact time. Under acidic conditions, higher adsorption efficiencies of the PGMA/mCHT nanoparticles due to intermolecular interactions of dye molecules between the protonated amine groups and the sulfonyl groups. Bi-solute adsorption was also investigated revealing between dye molecules has no competitive effect at the same initial concentration. The kinetic results of RR120 and IC adsorption onto PGMA/mCHT nanoparticles fit well to the pseudo-second-order model. The desorption of dye molecules from PGMA/mCHT nanoparticles was also studied using an alternating magnetic field which is caused the superior desorption behavior demonstrating the magnetic nanoparticles can be acted as a nanoheater.

Automated summary

Chitosan-based nanoparticles were prepared and used for the adsorption of anionic dyes. The results showed that under acidic conditions, the nanoparticles had higher adsorption efficiency and the adsorption process followed a pseudo-second-order kinetic model. Additionally, the study found that there was no competitive effect among dye molecules at the same initial concentration. Furthermore, the use of an alternating magnetic field for dye desorption demonstrated that the magnetic nanoparticles could act as a nanoheater and exhibit superior desorption behavior.