Removal of Anionic Azo Dye from Aqueous Solution Using the Magnetic NiFe2O4 Decorated-Exfoliated Graphite

Abstract

Environmental issues have recently become more prevalent with the rapid development of global industrialization. Organic dyes, a common pollutant, are compounds which are constituted by benzene rings, making them stable and presenting a pollution source that is harmful to human health. In this study, a new nanocomposite adsorbent was fabricated using exfoliated graphite (EG) and NiFe2O4 and evaluated for adsorption capacity against Congo Red (CR) dye. A number of reaction parameters (pH, CR concentration, dosage and contact time) that affect CR adsorption were considered. The successful synthesis of EG@NiFe2O4 was confirmed by FT-IR analysis. Herein, EG@NiFe2O4 and NiFe2O4 adsorbent with dosage of 0.5 g/L were used to removal 100 mL of CR dye at the concentration of 50 ppm. The results showed that adsorption equilibrium was achieved after 120 min for both adsorbents (EG@NiFe2O4 and NiFe2O4). The optimal working pH for adsorption using EG@NiFe2O4 and NiFe2O4 was 6 and 4 respectively. EG@NiFe2O4 could be reused for up to three times without significant loss of adsorption capacity.