Ao Chenghong, Shan Mai, Zhang Yue, Li Xiang, Kong Ying, Dong Xinwei, Liu Yang, Wu Danping
Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, China.
School of Energy and Environment Science, Yunnan Normal University, Kunming 650500, China.
Molecules. 2025 Apr 11;30(8):1717. doi: 10.3390/molecules30081717.
Biochar has attracted considerable interest owing to its high adsorption capacity; however, the mechanisms through which environmental factors influence the release of adsorbed pollutants remain unclear. This study investigates the adsorption and desorption dynamics of Rhodamine B (RhB) on biochars B2 and B6, which were pyrolyzed at temperatures of 200 °C and 600 °C, respectively, under varying conditions. The results indicated that there was no significant difference in removal efficiency at low RhB concentrations; however, at a concentration of 600 mg/L, biochar B2 had a higher removal efficiency than B6, likely attributable to more adsorption sites. Increased temperatures were found to enhance desorption from both B2 and B6, with B6 exhibiting a faster desorption rate. This phenomenon may be due to the stronger hydrogen bonding between B2 and RhB, which could inhibit desorption. In addition, elevated pH values facilitated desorption, presumably through electrostatic repulsion. Under alkaline conditions, B2 released a greater amount of dissolved organic matter (DOM), leading to increased RhB desorption relative to B6. This study offers a valuable reference for evaluating the environmental risk associated with the application of biochar in real-world settings.
生物炭因其高吸附能力而备受关注；然而，环境因素影响吸附污染物释放的机制仍不明确。本研究考察了罗丹明B（RhB）在分别于200℃和600℃温度下热解的生物炭B2和B6上的吸附和解吸动力学，实验条件各异。结果表明，在低RhB浓度下，去除效率无显著差异；然而，在浓度为600mg/L时，生物炭B2的去除效率高于B6，这可能归因于更多的吸附位点。研究发现，温度升高会增强B2和B6的解吸，其中B6的解吸速率更快。这种现象可能是由于B2与RhB之间较强的氢键，这可能抑制了解吸。此外，pH值升高促进了解吸，推测是通过静电排斥作用。在碱性条件下，B2释放出更多的溶解有机物（DOM），导致相对于B6，RhB的解吸增加。本研究为评估生物炭在实际应用中的环境风险提供了有价值的参考。
