1) Research objective: Our research focuses on the extraction and characterization of extracellular polymeric substances (EPS) from activated sludge. All the samples primarily activated sludge, are collected from lab-scale and full-scale wastewater plants. 2) Data collection and type: The data type is the results associated with the chemical and physical characteristics of sludge and EPS samples. All chemical and physical measurements are based on laboratory instruments. Specifically, after collection, the hot alkaline protocol is applied to extract EPS. Subsequent analyses include total proteins and total sugars, functional groups, monosugars, staining methods, and microscopic visualization, all conducted following standard methods. 3) Data statistic: Raw data is analyzed and designed using the Excel and Origin software. No scripts and relevant coding methods are used in our research. Further analysis of the results and mechanism can be found in the main text of the thesis.