Removal of Copper (II) Ions from Aqueous Solution Using Manganese Oxide Nanopowder

Abstract

Copper is a widely used metal for various applications such as electroplating, building applications, industrial machinery and the electronics industry. There is increasing concern about the environmental issues related to copper heavy metal in the wastewater produced by the copper mining industry. The present work focuses on treating copper (II) ions using manganese oxide (MnO2) nanopowder. The MnO2 nano-material was synthesised using the combustion process and characterised using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). It was found that it mainly contained crystalline α-MnO2. The effect of variables including the initial pH, contact time, initial concentration and adsorbent dose that influence the adsorption process was studied. Results showed that under best conditions, i.e., 500 mg/L initial concentration, 15 g/L absorbent dosage, 3 hours contact time, initial pH of 5.0 and a stirring speed of 120rpm, copper (II) was reduced to non-detectable levels. The high concentration of copper was reduced effectively by MnO2 nanoparticles. Isotherm and kinetics of the adsorption process were studied. Kinetic data followed Ho’s pseudo-second-order kinetics. This study indicated that MnO2 nano-material has a tremendous potential to remove copper (II) ions.