Liu, XiaocenBiosolids contain high contents of soil-required nutrients, so that have been widely applied in land application. The production of the biosolids depends on the clarification performance and dewaterability of the sludge, which are influenced by bioflocculation and structured water content, respectively. Therefore, research on sludge bioflocculation improvement and structured water content determination were proposed in this study. The result indicated that different activated sludge exhibited various bioflocculation limitations. Influence of the sludge characteristics such as the extracellular polymeric substances (EPS) composition, viscosity and floc size on the structured water content were also investigated. The results indicated that no significant correlation was observed between the EPS composition and the structured water content, however, the sludge floc size was positively correlated with it. The bioflocculation limitations were pinpointed, and how floc size influenced the structured water content needed further studies to improve sludge dewaterability, therefore, enhance the biosolids production quantitatively and qualitatively.enThesisEnvironmental engineeringactivated sludgebioflocculationbiosolidsextracellular polymeric substances (EPS)polymerstructured water content