Dynamic variation in physicochemical properties of activated sludge floc from different WWTPs and its influence on sludge dewaterability and settleability

•Dynamic change in physicochemical properties of activated sludges was investigated.•Variation in sludge EPS properties from different WWTPs showed a similar pattern.•Temperature had more significant influence on distribution and composition of EPS.•Sludge dewaterability correlated well with the content of proteins in soluble EPS.•Sludge settleability was primarily affected by floc size distribution and VSS.