Adsorptive remediation of organic pollutant and arsenic (V) ions from water using Fe3O4-MnO2 nanocomposite

Abstract

The presence of various pollutants in water poses a threat to human health. In this study, we focused on the removal of organic pollutant methylene blue (MB) and As(V) from the water by using Fe3O4-MnO 2 nanocomposite. The surface area of the as-prepared nanocomposite was found to be 237.39 m2/g. The nanocomposite was further characterized by using analytical techniques like powder XRD, SEM, VSM and transmission electron microscope. The results of the transmission electron microscope (TEM) showed Fe3O4 cores coated by a MnO 2 shell. VSM analysis showed that the Fe3O4-MnO 2 nanocomposite has ferromagnetic behavior. The efficiency of Fe3O4-MnO 2 nanocomposite for the removal of methylene blue (MB) and As(V) from the water was studied by varying the pollutant concentration and contact time. The results showed a maximum adsorption capacity of 146.1 mg/g for MB and 16.6 mg/g for As(V). The sorption equilibrium data fitted to Langmuir adsorption model for both MB and As(V) adsorption. The nanocomposite was magnetically separable and tested for five consecutive adsorption–desorption cycles. The Fe3O4-MnO 2 nanocomposite retained 70% of its adsorption capacity over five consecutive cycles of regeneration for MB as well as As(V). The result obtained suggest that Fe3O4-MnO 2 nanocomposite can be a promising adsorbent for the removal of methylene blue and As(V) present in water.