Study on dewaterability of municipal sludge conditioning by physical conditioners with ultrasonic and magnetic field application

AbstractAn experimental research on dewaterability of municipal sludge with different mixing ratios was conducted with the use of ultrasonic and magnetization as conditioning means, and quicklime powder and straw fiber as conditioners. Research indicates that conditioning by combination of ultrasonic, physical conditioners (quicklime and straw fiber), and magnetization can effectively improve the dewaterability of municipal sludge. U-O-M (represents treating the sludge successively with ultrasonic, physical conditioners and magnetic field) achieved the best dewaterability of municipal sludge through an experiment under the following conditions: 30 s 40 Hz ultrasonic treatment, 4% quicklime powder content, 1% fiber content, and 40 min magnetization with 20 mT strength. The water content after centrifugal dewatering with a 3,000 separation factor was lower than 60%.