According to the sludge treatment that needs to be dehydrated, flocculants of different ionic degrees can be screened through small experiments to select the most suitable polyacrylamide, so as to obtain the best flocculation effect, minimize the amount and save costs. The key to ionic degree selection:
(1) floc size: too small floc will affect the drainage speed, too large floc will bind more water and reduce the mud cake degree. The size of the flocculant can be adjusted by selecting the molecular weight of the polyacrylamide.
(2) floc strength: Floc should remain stable and not break under shearing. Increasing the molecular weight of polyacrylamide or selecting suitable molecular structure is helpful to improve the stability of the floc.
(3) The polyacrylamide must fully react with the sludge treatment at a certain location in the dewatering equipment to produce flocculation. Therefore, the viscosity of the polyacrylamide solution must be appropriate, and it can be fully mixed with the sludge treatment under the existing equipment conditions. Whether the two solutions are blended evenly is a key success factor. The viscosity of polyacrylamide solution is related to its molecular weight and concentration.
(4) Good dissolution can give full play to the flocculation effect. As mentioned above, the dissolution process of polyacrylamide is actually the maturation process of polyacrylamide, and sometimes it is necessary to speed up the dissolution rate, so consider increasing the concentration of the polyacrylamide solution.