Enhanced dewaterability of waste-activated sludge by combined cationic polyacrylamide and magnetic field pretreatment

However, subjecting to a combination of MF pretreatment and CPAM conditioning, sludge dewaterability was significantly enhanced beyond the level observed of CPAM addition alone. The lowest CST and SRF values of 36.5 s and 0.75 × 10 12 m kg −1 , respectively, were obtained when sludge was co-conditioned by CPAM (at a dosage of 40 mg L −1 ) and MF (at an induction of 40 mT) for 30 min, suggesting the optimal condition for enhancing sludge dewaterability.

It is also shown from the significant correlations between EPS, protein, polysaccharide and CST/SRF that the increment of EPS concentration in sludge supernatant may be the major reason for the enhancement of dewaterability.