微生物预处理与微波热解强化竹炭吸附CO₂性能研究

Enhancing CO₂ Adsorption Performance of Bamboo Biochar via Microbial Pretreatment Combined with Microwave Pyrolysis

摘要: 为提高竹炭(BC)对CO₂的吸附性能，本研究采用厌氧微生物对其进行预处理，而后使用微波进行二次热解获得改性生物炭(WBC)，考察了改性生物炭对CO₂的吸附性能。结果发现，微生物处理会因代谢产物的堵塞导致生物炭比表面积下降，相较于BC (182.35 m²/g)，处理1周(WBC-1)与2周(WBC-2)的改性生物炭比表面积分别降至76.88 m²/g和65.50 m²/g。微生物与微波处理后的生物炭对CO₂的吸附容量较原始生物炭有所增加，可由44.78 mg/g提高至48.80 mg/g (WBC-1)。通过动力学分析发现，伪二级动力学模型相比伪一级模型能够更好地描述生物炭对CO₂的吸附作用，表明生物炭对CO₂的吸附过程并非单一的物理吸附，还可能存在化学吸附。另外，生物炭对CO₂的吸附行为更符合Langmuir模型，结果显示生物炭对CO₂的吸附以单分子层吸附为主。

Abstract: To improve the CO₂ adsorption performance of bamboo biochar (BC), this study adopted anaerobic microorganisms for pretreatment, followed by microwave-assisted secondary pyrolysis to prepare modified biochar (WBC). The CO₂ adsorption properties of the modified biochar were systematically investigated. Results showed that microbial treatment led to a decrease in the specific surface area of biochar due to pore clogging by metabolic products. Compared with pristine BC (182.35 m²/g), the specific surface areas of WBC treated for 1 week (WBC-1) and 2 weeks (WBC-2) reduced to 76.88 m²/g and 65.50 m²/g, respectively. Nevertheless, the CO₂ adsorption capacity of biochar modified by microbial pretreatment and microwave pyrolysis was higher than that of raw BC, increasing from 44.78 mg/g to 48.80 mg/g (WBC-1). Kinetic analysis indicated that the pseudo-second-order kinetic model fitted the adsorption process better than the pseudo-first-order model, suggesting that the CO₂ adsorption on biochar involves not only physical adsorption but also chemical adsorption. Additionally, the adsorption behavior of CO₂ on biochar was more consistent with the Langmuir model, indicating that the adsorption is dominated by monolayer adsorption.