A magnetic amino enriched hydrothermal carbon production with molasses as carbon source

Magnetic molasses hydrothermal carbon (MMHC) with many amino groups was prepared in one step by in situ modification using molasses wastewater as an amino-rich carbon source and FeCl3 and FeCl2 as precursors of Fe3O4. MMHC was characterized by FT-IR, SEM, XRD, TGA, XPS, and magnetic property tests, and the hydrothermal carbonization pattern of molasses wastewater was investigated. The adsorption behaviors of MMHC on heavy metal ions (Pb2+, Cu2+, Cd2+) were simulated and discussed to refine and deepen the adsorption mechanisms between different heavy metal cations and amine-based adsorbents. The compositional analysis showed that almost all the amino acids in the molasses wastewater were involved in the hydrothermal reaction. Characterization showed that amino groups dominated the adsorption of heavy metal ions, and the adsorption of Pb2+, Cu2+ and Cd2+ on MMHC satisfied the Langmuir model and the pseudo-secondary kinetic model. The maximum adsorption capacities of MMHC for Pb2+, Cu2+ and Cd2+ under ideal conditions were 51.81, 21.41 and 17.64 mg/g, respectively. This work provides an effective new direction for the treatment of heavy metal pollution in water bodies and the resourceful reuse of sugar-containing wastewater.