Interaction mechanism of biochar dissolved organic matter (BDOM) and tetracycline for environmental remediation

Abstract

The persistent organic pollutant of water by residual antibiotics, particularly tetracycline, posed serious environmental and health risks. Biochar dissolved organic matter (BDOM) sorbed pollutants and mitigated migration and transformation. This study investigates the binding interaction mechanisms between BDOM and tetracycline under varying pyrolysis temperatures biochars and pH, with fluorescence quenching techniques. The influence of biochar pyrolysis temperature on tetracycline adsorption behavior by BDOM-tetracycline was also researched. The key results revealed that higher pyrolysis temperatures and lower solution pH enhanced the binding affinity of BDOM for tetracycline, which was mainly attributed to increased aromaticity and reduced oxygen-containing functional groups. The hydrophobic forces of biochar dominated the interaction, with positive enthalpy (ΔH) and entropy (ΔS) values confirming an endothermic, entropy-driven process. The BDOM modified the mobility and bioavailability of tetracycline in the process of environmental pollution remediation, which not only enhances plant growth, but also mitigates ecological risks.