微生物处理时间对生物炭吸附CO₂性能的影响

The Influence of Microbial Treatment Time on the CO₂ Adsorption Performance of Biochar

摘要: 为提高竹炭对CO₂的吸附能力，使用厌氧微生物对竹炭进行处理，研究微生物处理时间(1~4周)对生物炭孔隙结构及吸附CO₂性能的影响。结果表明，微生物处理能够明显改善生物炭的孔隙结构，处理2周后比表面积由182.36 m²/g提高至288.93 m²/g。然而过长的处理时间会导致比表面积有所下降，处理4周后MBC-4的比表面积降至121.10 m²/g。微生物处理后生物炭表现出较佳的CO₂吸附性能，吸附量由42.36 mg/g可提高至48.28 mg/g，相较于原始竹炭增加了14%。通过伪一级和伪二级动力学模型研究了生物炭对CO₂的吸附过程，发现伪二级动力学模型能更好的描述生物炭对CO₂的吸附，表明生物炭对CO₂的吸附除了物理吸附外，还存在化学吸附。吸附等温线拟合结果显示Langmuir模型对生物炭吸附CO₂的拟合优于Freundlich模型。

Abstract: To enhance the CO₂ adsorption capacity of bamboo biochar, anaerobic microorganisms were used to treat bamboo biochar. This study investigated the effects of microbial treatment time (1-4 weeks) on the pore structure of biochar and its CO₂ adsorption performance. The results showed that microbial treatment significantly improved the pore structure of biochar: after 2 weeks of treatment, the specific surface area increased from 182.36 m²/g to 288.93 m²/g. However, an excessively long treatment time led to a decrease in the specific surface area; after 4 weeks of treatment, the specific surface area of MBC-4 dropped to 121.10 m²/g. After microbial treatment, the biochar exhibited better CO₂ adsorption performance, with the adsorption capacity increasing from 42.36 mg/g to 48.28 mg/g, representing a 14% increase compared to the original bamboo biochar. The adsorption process of CO₂ by biochar was studied using pseudo-first-order and pseudo-second-order kinetic models. It was found that the pseudo-second-order kinetic model could better describe the CO₂ adsorption by biochar, indicating that in addition to physical adsorption, chemical adsorption also occurred in the CO₂ adsorption process by biochar. In addition, the Langmuir model is more suitable for fitting the adsorption of CO₂ by biochar than the Freundlich model.