Adsorption of Co(II) from aqueous solution using municipal sludge biochar modified by HNO.

Here adsorption studies were proposed on a carboxylated sludge biochar (CSB) material modified by HNO to assess its capacity in the removal of cobalt from aqueous solution. The as-prepared sludge biochar material was characterized by Brunauer-Emmett-Teller (BET) analysis, Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The isotherm process could be well described by the Langmuir isotherm model.