New insight into dewatering of digested sludge via polyacrylamide flocculation conditioning: Transformation from binary gel-like structure to gel-like structure at flocs level.

Polyacrylamide conditioning transforms the gel-like structure of digested sludge, with the gel-like structure at flocs level remaining crucial for dewatering efficiency.

• Why it matters: Understanding the structural mechanisms of digested sludge dewatering is essential to improve process performance, as current challenges stem from unclear interactions within its gel-like properties.
• What they did: The study analyzed the binary gel-like structures in raw and PAM-conditioned digested sludge, using microrheological tests and correlation analysis on 90-130 pN stress relaxation forces and other indicators.
• The result: Findings show that the gel-like structure at flocs level maintains a strong positive correlation with dewatering performance, guiding strategies to enhance sludge dewaterability through structural control.