通过元素分析、红外光谱和热重分析探讨了4种不同来源生物炭(玉米芯、香蕉杆、草海底泥、泥炭土)的理化性质及热稳定性.结果表明,生物炭的制备是一个逐渐从“软质碳”向“硬质碳”过渡的过程,制备过程中生物炭含碳量增加,芳香性增强,形成致密的碳结构,其中的含氧官能团被大量烧失,极性减弱,憎水性增强.不易被土壤中的微生物利用,有利于增加生物炭在土壤中的稳定性.热重实验显示,沉积物生物炭拥有比植物生物炭更好的热稳定性,这是因为沉积物中无机矿物对有机质起到了保护作用.
In this study, the chemical properties and thermal stability of biochar from different origins were investigated by element analysis, infrared spectra and thermogravimetric analysis. In the preparation process of biochar, the oxygen functional groups of plants and sediment were greatly removed, leading to enhanced hydrophobicity and thermal stability of the biochar. Additionally, the thermal stability of biochar from sediment was higher than that form plant due to the protection of mineral, implying that the biochar from sediment could sequestrate carbon more stably and effectively.