Study on Co-Pyrolysis and Characteristics of Calcite/Biochar Composites

There has been an increasing recognition of the efficacy of various clay mineral elements in absorbing heavy metallic ions, which can be attributed to their cost-effectiveness, widespread, precise floor area, and remarkable practical groups. A co-pyrolyzing calcite/biochar (CP-CAL/BC) composite was prepared in this study by co-pyrolyzing calcite (CP-CAL) and coconut shell (CS) at 650–750 °C. Several methods were employed to analyze the properties of the synthesized composite. The composite showed efficient adsorption of Pb2+ at a pH of 4.5, primarily by the process of monolayer chemisorption, which is influenced by the composite’s pore structure and boundary layer diffusion. After several repeated experiments, it was observed that all of the CP-CAL/BC composites possessed exceptional regeneration capabilities, consistently removing Pb2+ at high rates. The CP-CAL/BC composite produced at 750 °C showed the greatest extent of resistance to corrosion, surpassing all other composites with a decrease in corrosion of 7.298 × 10−6 A/cm2. The present study confirmed that the CP-CAL/BC composite material has efficient adsorption features for Pb2+ and strong regenerative capability. Furthermore, the material synthesized at high temperatures demonstrated superior corrosion resistance.