Adsorption removal of copper (II) and chromium (VI) from wastewater by Fe3O4-loaded granular activated carbon

Abstract

Abstract Combining with the characteristics of Fe3O4 and activated carbon, magnetic granular activated carbon (GAC–Fe3O4) was prepared by chemical coprecipitation. With GAC–Fe3O4 as the adsorbent, the effects of GAC–Fe3O4 dosage, the initial pH of wastewater temperature, and the initial concentration of copper (II) and chromium (Ⅵ) on the removal performance were explored. The adsorption process of copper (II) and chromium (VI) on magnetic GAC was studied using adsorption kinetics, adsorption isotherms, scanning electron microscopy, and infrared spectroscopy. The experimental results indicate that among these influencing factors, the pH value of wastewater plays a vital role in the removal efficiency. When the pH value was 6 and 2, the initial concentration of copper (II) and chromium (VI) ions was 5 ppm, the optimum removal efficiencies of copper (II) and chromium (VI) were 99.98 and 96.39%, respectively. As to the adsorption mechanism of GAC–Fe3O4, the adsorption of copper (II) and chromium (VI) in wastewater was more consistent with the Langmuir model. The adsorption process in this study can be well explained by the pseudo-second-order kinetic model.