The test used sludge capillary water absorption time (CST) and sludge centrifugal moisture content as indicators of dehydration evaluation.
Sludge capillary water absorption time
20 mL of sludge was added to a plexiglass cylinder with a diameter of 20 mm. The Whatman chromatographic paper between the two plexiglass plates would absorb water from the sludge and record the time required for the chromatographic paper to have a wet radius of 2 cm. Sludge CST
Sludge centrifugal moisture content
Pour a certain amount of sludge into a centrifuge tube, centrifuge at a speed of 2 000 r / min for 30 min, then remove the mud cake in the centrifuge tube, dry it at 105 ° C in a constant temperature oven to constant weight, and cool. Heavy, calculated filter cake moisture content.
Flocculant sludge conditioning test conditions
1 L of sludge was taken separately, and the sludge conditioning test was simultaneously carried out under the same stirring speed and time (stirring at 350 r/min for 60 s and then at 60 r/min for 10 min).