Removal of Ni(II) from aqueous solutions using activated carbon with manganese formate hydrate in-situ modification

Activated carbon (AC) derived from Phragmites Australis (PA) with phosphoric acid activation as a low-cost adsorbent is extensively used in water treatment. In this study, a novel manganese formate hydrate (MFH) in-situ modified activated carbon (AC-MFH) has been proposed and investigated. The physical and chemical characteristics of adsorbents were characterized by N 2 adsorption/desorption, Fourier transform infrared (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that AC-MFH had more microporous structures and surface oxygen-containing functional groups than AC. The Ni(II) adsorption behaviors of adsorbents were investigated by batch experiments, the results suggested that AC-MFH showed 20% higher Ni(II) adsorption capacity than that of AC and the associated adsorption isotherms and kinetics well fitted to the Langmuir model and pseudo-second-order model, respectively. The Ni(II) adsorption mechanisms of AC-MFH were investigated by FTIR and XPS analysis. These results indicated that the adsorption of Ni(II) mainly depended on the surface chemistry between the Ni(II) and surface oxygen-containing functional groups.