Adsorption and removal of malachite green from aqueous solution using magnetic β-cyclodextrin-graphene oxide nanocomposites as adsorbents

Dye pollution has become one of the most important environmental issues. Simple and effective approaches aiming at the rapid removing of dye from environment were in demand. The magnetic pcyclodextrin-graphene oxide nanocomposites (Fe3O4/beta-CD/GO) were prepared as novel adsorbents. The composition and morphology of prepared materials were characterized by Fourier infrared spectrometry (FT-IR), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). The Fe3O4/beta-CD/GO nanocomposites were utilized in the adsorptive removal of malachite green in aqueous solution. The factors such as adsorption time, adsorption temperature, pH of solution, adsorption kinetics and isotherms were investigated. The results indicated that the Fe3O4/beta-CD/GO nanocomposites had good adsorption ability and the maximum adsorption capacity was 990.10 mg/g at 45 degrees C and pH 7. The adsorption capacity remained at 80% after five cycles. Removal rate could reach 98% after three times of adsorption. The adsorption process with malachite green was found that fitted pseudo second order kinetics equations and the Langmuir adsorption model. In addition, the thermodynamic was investigated to indicate that the adsorption process was spontaneous and endothermic in nature. The experimental results showed the Fe3O4/beta-CD/GO nanocomposites had a good adsorption ability to remove dyes in wastewater and can be rapidly extracted from water. (C) 2014 Elsevier B.V. All rights reserved.