Enhancing data reliability in quantitative characterization of moisture distribution in sludge using DSC: Impact of sample attributes and test parameters

Exploring moisture distribution, especially bound water content, is vital for studying and applying sludge dewatering. The differential scanning calorimetry (DSC) method has been extensively utilized for the quantitative characterization of moisture distribution in sludge. However, this method has certain limitations, such as low reproducibility of results, leading to controversial parameter values in different papers and hindering result comparison. In this study, we investigated the influence of key sample attributes on measuring sludge bound water using the DSC method.The findings demonstrated that the moisture content and mass of sludge samples substantially influenced the reproducibility and stability of DSC test results. To ensure data reliability, the moisture content of the sludge sample should be minimized and kept below 84%, with the mass not exceeding 10 mg. Compared to the influence of sludge moisture content and sample mass, the heating rate (1⁓5 °C/min) minimally affected DSC test results. This study offers a comprehensive insight into how sample attributes and test parameters affect the quantitative characterization of bound water in sludge using the DSC method. Furthermore, practical strategies are presented to enhance the method's applicability in sludge bound water characterization.