Work

Ultrasonic-Assisted K+ Modification of Industrial Hemp Stalk Hydrothermal Biochar for Highly Effective Adsorption of Pb2+

Year: 2025

Type: article

Abstract: Biochar modification represents an effective approach for enhancing adsorption capacity. In the research, industrial hemp straw-derived biochar was synthesized through hydrothermal carbonization coupled with ultrasound-assisted KOH activation, demonstrating exceptional Pb2+ adsorption efficiency. The optimal HBS50-K0.5M exhibited excellent adsorption performance, achieving the maximum adsorption capacity of 345.8 mg/g within 2 h. The etching effect of KOH on the biochar surface increased the O-containing functional groups, which enhanced the adsorption of Pb2+. The adsorption kinetics revealed that the adsorption process of Pb2+ was aligned with the pseudo-second-order kinetics as well as the Langmuir model. The complexation, ion exchange, π-π interaction, as well as electrostatic interaction participated in the adsorption. This study demonstrates that ultrasound-assisted KOH-activated biochar has great potential for removing Pb2+ from wastewater.

Source: Materials

DOI: 10.3390/ma18102348