土壤腐殖酸慢热解表征实验影响因素研究

以土壤提取的腐殖酸为研究对象,进行了差式量热扫描(DSC)和热重分析(TGA)的可重复性实验、样品质量对比实验和预处理对比实验。综合分析了影响慢热解特征温度参数的因素和效应,并根据作用原理将其总结为热滞后效应和反应平衡滞后效应。结果表明,高级热分析技术用于土壤慢热解表征可重复性良好,差式量热扫描与热重分析结果可比性强,然而热分析曲线和热特征参数对实验条件的响应灵敏,其中样品质量和升温速率的影响尤其显著。研究结果表明,慢热解技术用于土壤有机质分析具有良好的准确性和重现性,提出了保障土壤腐殖酸慢热解质量控制的最佳样品量DSC为(10±0.1)mg]、最佳气体氛围(He)和最佳升温速率(10℃/min)、精确压实程度等实验条件。

Influence of Experimental Conditions on Slow Pyrolysis Characterization of Soil Humic Acid

Take soil humic acid as the research object, the repeatability experiments, quality comparison experiments and pretreatment comparison experiments were carried out by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The factors and effects that affect the temperature parameters of slow pyrolysis were analyzed, and the two principles of heat lag effect and reaction equilibrium lag effect were summarized. The results showed that the advanced thermal technique used for soil slow pyrolysis characterization had good repeatability, and the results of DSC and TGA results were highly comparable. The thermal analysis curves and thermal characteristic parameters sensitively responded to the purge gas, crucible property and other factors, while the influence of sample quality and heating rate was particularly significant. The research results are important for promoting the application of thermal analysis technology in soil monitoring and evaluation.