New insights into membrane fouling based on characterization of cake sludge and bulk sludge: An especial attention to sludge aggregation

- Cake and bulk sludge aggregation in MBR was evaluated by extended DLVO theory.
- Cake sludge had higher DSI and more colloids, LB-EPS and negative charge.
- Cake sludge exhibited worse aggregation ability than bulk sludge.
- Worse sludge aggregates was more easily attached to membrane for cake formation.