A: You can’t mix them. Because anionic polyacrylamide and cationic polyacrylamide mixed use, charge offset, molecular weight reduction, will produce white flocculent precipitate, can not play any role in water treatment.
Under normal circumstances, in different reaction sedimentation tanks, anionic polyacrylamide should be used for settlement, and then cationic polyacrylamide for sludge dehydration.
Polyacrylamide and its derivatives can be divided into anionic, cationic, nonionic and amphoteric types according to the charge they carry. Different types of polyacrylamides have different properties, and different polyacrylamides within the same type have different properties.
The condensation effect of polyacrylamide is mainly carried out through two aspects, one is through hydrogen bonding, van der Waals force and electrostatic bonding and other effects on the adsorption of colloidal particles, the other is through the linear polymer chain in the solution adsorption bridging effect to adsorption and entanglement of many small particles.
Anionic polyacrylamide is suitable for particle surface with positive charge water treatment, cationic polyacrylamide flocculant mainly flocculating surface with negative charge colloidal particles.
The flocculation capacity of nonionic polyacrylamide is less affected by salt content and pH than that of anionic polyacrylamide and cationic polyacrylamide because it has no ionic functional group.
Amphoteric polyacrylamide is special because it contains both anionic and cationic functional groups. The content and distribution of both have great influence on its flocculation and filtration aid.
In general, different ionic polyacrylamide can not be used in combination, but can be used in front and back ends.
Polyacrylamide (PAM) is a linear polymer, chemical formula is (C3H5NO) N. It is a hard glassy solid at room temperature. The products are liquid glue, latex and white powder particles, translucent beads and flakes. Good thermal stability. Can be dissolved in water in any proportion, aqueous solution is uniform transparent liquid. After long-term storage, the solution viscosity will decrease due to slow degradation of polymer, especially when the storage conditions are poor.  Polyacrylamide, as lubricant, suspension agent, clay stabilizer, oil displacement agent, water loss reducer and thickener, has been widely used in drilling, acidification, fracturing, water plugging, cementing and secondary oil recovery, tertiary oil recovery. It is a very important oil field chemical.Learn more
Polyferric sulfate is a kind of inorganic polymer coagulant with superior performance. It is a light yellow amorphous powdery solid and easily soluble in water. 10% (mass) aqueous solution is red-brown transparent solution and hygroscopic. Polyferric sulfate is widely used in drinking water, industrial water, all kinds of industrial waste water, municipal sewage, sludge dewatering purification treatment.Learn more