Lead and antimony removal from wastewater via tea residue derived hydrochar: Immobilization capacity and industrial practicality

Lead and antimony often co-occurr in mining wastewater. In this study, magnetic hydrochar (MHC) was synthesized from tea residue using a simple hydrothermal treatment. Various characterization techniques confirmed the incorporation of iron into the tea residues. The MHC demonstrated excellent ability to remove both Pb(II) and Sb(III) with adsorption capacity of 328.2 and 411.1 mg/g, respectively. Furthermore, the practical applicability of MHC was evaluated through continuous columns as well as a real wastewater purification study. This work provided insights into the potential of MHC as an environmentally functional material for purifying heavy metal-polluted wastewater. • Magnetic hydrochar was synthesized using waste tea residue. • Characterizations were employed to investigate MHC. • Removal capacity reached 328.2 and 411.1 mg/g for Pb(II) and Sb(III), respectively. • Adsorption mechanisms involved complexation, electrostatic attraction, ion-exchange, and oxidation. • Practicality was evaluated by column study, cost assessment, and real wastewater treatment.