The modified biochar from wheat straw by the combined composites of MnFeO nanoparticles and chitosan Schiff base for enhanced removal of U(VI) ions from aqueous solutions.

In the last few decades, U(VI) is a significant environmental threat. The innovative and environmentally friendly adsorbent materials for U(VI) removal were urgent. Preparation of the modified biochar from wheat straw by combined composites of MnFeO nanoparticles and chitosan Schiff base (MnFeO@CsSB/BC) was characterized, and adsorption experiments were carried out to investigate the performance and interfacial mechanism of U(VI) removal. The results showed that MnFeO@CsSB/BC exhibited high adsorption capacity of U(VI) compared with BC. The adsorption process of U(VI) removal by MnFeO@CsSB/BC could be ascribed as pseudo-second-order model and Langmuir model. The maximum adsorption capacity of U(VI) removal by MnFeO@CsSB/BC reached 19.57 mg/g at pH4.0, 30 mg/L of U(VI), and 25 °C. The possible mechanism was a chemical adsorption process, and it mainly contained electrostatic attraction and surface complexation. Additionally, it also was an economic and environmental friendly adsorbent.