High-efficiency Pb(II) removal from wastewater by β-cyclodextrin modified magnetic biochar composite: Adsorption performance and mechanism

In this study, a β-cyclodextrin (CD)-modified magnetic biochar composite (MEC-CD) was prepared for the efficient removal of Pb(II) from wastewater in order to address the problem of Pb(II) contamination. MEC-CD demonstrated excellent adsorption performance under varying pH and temperature conditions, achieving adsorption equilibrium within 120 min with a maximum adsorption capacity of 226.7 ± 1.3 mg/g—3.54 times that of unmodified biochar. The adsorption process conformed to the pseudo-two-stage kinetic model and Langmuir model, indicating a monolayer adsorption process dominated by chemical adsorption. In practical aquatic environments, MEC-CD achieved Pb(II) removal rates exceeding 90% across five water samples. After 15 adsorption-desorption cycles, it retained 75.4 ± 0.45% of its initial adsorption capacity, demonstrating favorable recovery performance. The MEC-CD adsorbent successfully developed in this study holds promise as a Pb(II) adsorbent characterized by high adsorption efficiency, ease of recovery, and favorable recycling properties. It is anticipated to emerge as a promising Pb(II) adsorbent material with broad application prospects in wastewater treatment.