Efficient Removal of Pb (II) from aqueous waste by manganese oxide/modified activated carbon composites

The present composites (NMO/Modified AC) were prepared and utilized for the removal of Pb(II) from waste water through batch adsorption. Nano manganese oxide (NMO) was prepared by simple co-precipitation method / modified activated carbon which was treated with HNO₃(4M, 6M and 8M). The synthesized samples NMO, NMO/ (4M, 6M, 8M) AC and AC were characterized using X-Ray Diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Scanning Electron Microscope (SEM). Batch experiments were carried out under several conditions including ph, temperature, contact time, competing cation, and initial lead(II) ion concentration to remove lead (II) ions from liquid waste water. The results revealed that NMO, NMO / (4M, 6M, 8M) AC, and AC have a high adsorption efficiency (>99%). The adsorption results from the applied experiments fit the Langmuir isotherm, and the kinetic data follow pseudo-second-order model. in addition, the evaluation of thermodynamic parameters (ΔG°, ΔS° and ΔH°)from V ant Hoff equation indicated the spontaneous and exothermic nature of the adsorption