污泥脱水是污泥减量化的关键，长期以来，该领域的研究集中在优化脱水性能的层面，对于现实中存在且时有发生的脱水恶化现象缺乏关注。水分分布是影响污泥脱水性能的关键，现有研究普遍认为结合水→自由水的转化会优化污泥脱水性能，而对于自由水→结合水的转化是否存在及其与脱水恶化的响应关系，尚未见报道。本项目针对当前污泥脱水恶化机制缺乏关注和认知的现状，提出“基于自由水→结合水动态转化的污泥脱水恶化机制”假说，以水分的分布为切入点，综合运用低场核磁共振、热重和差热等技术，构建污泥不同形式水分分布的定量表征方法，系统研究不同水分之间的转化模式对污泥脱水性能的响应规律，阐明自由水和不同形态结合水之间的迁移路径及幅度对污泥脱水性能恶化的驱动机制，为深入理解污泥脱水恶化机制提供理论基础，为发展和完善污泥脱水过程机制提供理论拓展和补充。

Waste activated sludge dewatering is exceedingly important for reducing sludge volume and is the research hotspot in the field of sludge treatment. For a long time, sludge dewatering research has focused on developing high-performance dewatering process, while little attention has been paid to the deterioration of sludge dewatering that actually exists and occurs frequently in practice. The physical states of water are crucial to sludge dewatering performance, and the conversion of bound water into free water is widely regarded as the key point to improve dewatering efficiencies. However, to date, little is known about whether the conversion of free water into bound water exists and its response to the deterioration of dewatering efficiencies. Therefore, this project hypothesizes that the deterioration mechanism of sludge dewatering efficiencies can be revealed based on the dynamic conversion of free water → bound water. The distribution and quantification of water states is taken as the research entry point. The integrated use of low-filed nuclear magnetic resonance (LFNMR) and thermogravimetry differential scanning calorimetry is employed to quantitatively study the response of the conversion process of different forms of water to sludge dewatering efficiencies, and to clarify the driving mechanism of the conversion path and amplitude between free water and different forms of bound water to the deterioration of sludge dewatering performance. The results gained in this study would help provide new insights into the in-depth understanding of the deterioration mechanism of sludge dewaterability and hopefully improve our fundamental understanding of sludge dewatering.