Removal of Tetracycline from Water by Biochar: Mechanisms, Challenges, and Future Perspectives

作者：Lin Zhang, Wentao Yang, Yonglin Chen, Liyu Yang · 发表于：Water · 年份：2025 · DOI：10.3390/w17131960 · 被引用次数：16 · 研究领域：Pharmaceutical and Antibiotic Environmental Impacts、Adsorption and biosorption for pollutant removal、Advanced Photocatalysis Techniques

Tetracycline (TC) is widely used in medicine and livestock farming. TC is difficult to degrade and tends to persist and accumulate in aquatic environments, and it has gradually become an emerging pollutant. Biochar (BC) has strong potential for removing TC from water. This potential arises from its excellent surface properties, low-cost raw materials, and renewable nature. However, raw biomass materials are highly diverse, and their preparation conditions vary significantly. Modification methods differ in specificity and the application scenarios are complex. These factors collectively cause unstable TC removal efficiency by biochar. The chemical activation process using KOH/H3PO4 significantly enhanced porosity and surface functionality, transforming raw biochar into an activated carbon material with targeted adsorption capacity. Adjusting the application dosage and environmental factors (particularly pH) further enhanced the removal performance. Solution pH critically governs the adsorption efficiency: optimal conditions (pH 5–7) increased removal by 35–40% through strengthened electrostatic attraction, whereas acidic/alkaline extremes disrupted ionizable functional groups. The dominant adsorption mechanisms of biochar involved π–π interactions, pore filling, hydrophobic interactions, hydrogen bonding, electrostatic interactions, and surface complexation. In addition, the main challenges currently hindering the large-scale application of biochar for the removal of TC from w...