Study on the Dewatering Characteristics and Efficiency of Thickening Low Concentration Excess Sludge by Cavitation Air Floatation (CAF)

In order to study the dewatering characteristics and efficiency of thickening low concentration excess sludge by Cavitation Air Floatation(CAF), As CAF-5 is employed to thicken low concentration excess sludge in Chaoyangzhou WWPT, the influent flow is 5m3/h, the sludge concentration is 4g/L, the dosage of flocculant FO4440SH is 1.0 kg/tDS and the dosage of surfactant 1227 is 0.2 kg/tDS, the solid content ratio of thickening sludge is 6~7%, the sludge specific resistance to filtration is 2~2.5 × 10¹²m/kg. When the thickening sludge is dewatered directly by the sludge pressafiner, the solid content ratio of dewatering sludge is up to 22.4~23.8%. Comparing with that of dewatering sludge by integrated thicken-dewater machine of 20.5~22.2%, the dewatering characteristics of CAF is better, and the solid content ratio of dewatering sludge is higher.