Relative sludge specific resistance refers to the resistance of filter cake per unit filtration area per unit dry weight under a certain pressure, which is widely used to measure sludge dewatering performance. The lower the resistance ratio, the better the dewatering performance of sludge. With the increase of anionic polyacrylamide dosage, the specific resistance of sludge decreases first and then increases. When the amount of anionic polyacrylamide is between 50 and 75mg·L-1, the specific resistance is 2.88×1012 ~ 3.74×1012m·kg-1, which is lower than that without PAM.
According to the settlement performance test, the particles of the sludge flocculate after PAM conditioning are small, which is easy to enter the pores of the filter paper and cause blockage, thus increasing the specific resistance of the sludge. The sludge floc particles are larger, good permeability, not easy to plug the filter media pores, can effectively reduce the specific resistance of sludge. From the change of specific resistance of sludge, PAM with a molecular weight of 8 million and a hydrolysis degree of 20% had a better sludge conditioning effect, followed by PAM with a molecular weight of 6 million and a hydrolysis degree of 30%, and the dosage was still 75mg·L-1.
Basically all chemical raw materials will produce different effects in different environments, so it is necessary to determine the ratio of anionic polyacrylamide according to the actual operation, so as to play a better role.
