典型金属离子对生物炭稳定性的影响及驱动机制研究

生物质中广泛存在的金属离子对生物炭形成过程具有重要影响，会改变生物炭的碳结构和稳定性，进而影响其固碳减排功能。然而，金属离子对生物炭稳定性的影响机制仍待探明。对此，本项目以生物质中常见但类型不同的金属离子为研究对象，选取生物质的基本结构组分以及水稻秸秆为生物质原料，探究金属离子对生物炭稳定性的影响及驱动机制，重点研究：①采用热重-红外-质谱联用技术解析原料在浸渍金属离子溶液前后的炭化过程，揭示金属离子对原料热化学行为的影响；②将浸渍前后的原料制成生物炭，结合光谱、能谱分析和分子标志法等手段，阐明金属离子对生物炭微观结构的影响规律；③开展室内恒温培育实验，应用同位素示踪技术，探索生物炭在土壤中的降解动力学特征，量化金属离子对生物炭稳定性的影响，结合生物质热化学行为和生物炭微观结构信息，揭示其驱动机制。本项目将为高稳定性生物炭的研发提供理论依据和技术储备，以推进生物炭固碳减排技术的进一步发展。

The metal ions within biomass significantly influence the formation process of biochar, thereby affecting the carbon structure and stability of biochar. This would further exert an impact on the carbon sequestration potential of biochar. However, the influence and driving mechanism of metal ions within biomass on the stability of biochar remains unclear. To fill the knowledge gap, this program will select typical types of metal ions which commonly present in biomasses, and choose the rice straw and basic structural components (cellulose, hemi-cellulose and lignin) of biomasses as the feedstocks. Different concentrations of metal ions will be prepared and added into the feedstock by the means of impregnation. The TG-FTIR-MS analyzer will be adopted to investigate the impact of metal ions on the pyrolysis pattern of biomass. The biochar prepared from biomass with and without metal ions will be characterized using optical and energy spectrum in combination with molecular marker technology to investigate the impact of metal ions on the micro-structure of biochar. The incubation experiment under constant temperature will be performed to simulate the characteristics of biotic and abiotic decomposition of biochar in the soil. By using isotopic tracing technology, the influence of metal ions on the stability of biochar will be quantified and the underlying mechanism will be revealed based on the characterization data. This project will provide theoretical and technical support for the design of biochar with high stability, and promote the development of biochar as carbon negative emission technology.