Enhancement of Waste Activated Sludge Dewaterability by Potassium Ferrate Pretreatment

Abstract

Potassium ferrate was used to enhance sludge dewatering and the mechanism was studied. Sludge floc structure was effectively destroyed by potassium ferrate, and the soluble COD, proteins and polysaccharides increased with the increase of potassium ferrate. The optimal dose for sludge disintegration was 100 mg/gSS, and the corresponding maximal SCOD, soluble proteins and polysaccharides concentrations were 2455, 800 and 145 mg/L, respectively. Sludge dewaterability was enhanced significantly with cationic polyacrylamide (C-PAM) application, and the SRF decreased to 0.72×10 10 m/kg from 50.12×10 10 m/kg. This study indicated that the potassium ferrate pretreatment was helpful for enhancing sludge dewaterability and reducing the coagulant dose.