Efficient and stable removal of Pb (II) by coal gasification fine slag oxidized with potassium permanganate

After oxidation of coal gasification fine slag with potassium permanganate, a coal gasification fine slagmanganese oxide composite material,GFS-Mn, is obtained, which exhibits efficient and stable adsorption capabilities for heavy metal Pb (II). GFS-Mn was obtained by mixing and oscillating coal gasification fine slag with potassium permanganate solution for 8 h at 25 degrees C with GFS/KMnO4(aq) ratio of 1:20. GFS-Mn showed the maximum adsorption capacity of 398.41 mg center dot g-1 for Pb (II) due to the existence of the Mn-OH and -COOH groups on its surface. The adsorption for Pb (II) reached the equilibrium within 120 min and the GFS-Mn loaded with Pb (II) was eluted using pure water and acid solution (pH = 3 - 6), indicating that the adsorption result is highly irreversible, and the adsorbed Pb (II) cannot be released into the environment. In order to further learn the adsorption mechanism of Pb (II) by GFS-Mn, the adsorbents were analyzed by Electron microscopy, Fourier-Transform Infrared Spectroscopy and X-ray photoelectron spectrometer.