Characterization of the Adsorption of Cu (II) from Aqueous Solutions onto Pyrolytic Sludge-Derived Adsorbents

The adsorption of Cu (II) onto two typical types of pyrolytic sludge was investigated in this study. The examined conditions include pH, adsorption time, and temperature, as well as the dosage of adsorbents. Results show that the adsorbents removed the Cu (II) effectively. The adsorbent made from pyrolyzed paper mill sludge (Cu-MS) exhibited exceptional performance, with a removal efficiency of around 100%. Moreover, the adsorption of Cu (II) onto Cu-MS was not affected by pH in the range of 3-9. The kinetic data showed better conformation with the pseudo-second-order kinetic model, and the adsorption processes of the Cu-MS fit well to the Langmuir isotherm model. The adsorption capacity reached 4.90 mgg(-1) under appropriate conditions. Microscopic analysis and FT-IR analysis revealed that the adsorbent with porous structure and high monosilicate content was beneficial to Cu (II) adsorption. Thus, the Cu-MS is a potentially promising candidate for retaining Cu (II) in aqueous environments