Rapid and Efficient Removal of Cationic Dyes by Magnetic Chitosan Adsorbent Modified with EDTA

A novel magnetic EDTA–modified chitosan/SiO2/Fe3O4 adsorbent (EDCMS) was employed to remove cationic dyes from aqueous solutions. EDCMS exhibited rapid, efficient, and recyclable adsorption properties for crystal violet (CV) and methylene blue (MB) at pH 5.0-10.0. The adsorption preferably followed the pseudo-second kinetic and the Langmuir isothermal models with an exothermic nature, and the Langmuir maximum capacities reached 227.3 and 138.9 mg g−1 for CV and MB, respectively. Furthermore, EDCMS exhibited much high removal efficiency for both dyes and heavy metal ions in the bi–pollutants system containing low concentrations of heavy metal ions.