Anionic polyacrylamide is usually granular or emulsion type, and can be roughly divided into anionic polyacrylamide, cationic polyacrylamide and non-ionic anionic polyacrylamide according to different charges. The molecular weight is anionic>nonionic>cationic. The specific model to choose depends on the different sewage media to be treated. Under normal circumstances, this should be determined by collecting sewage samples on-site and testing them.
If there are too many dissolved substances in the water, the dissolution and flocculation effect will be unfavorable. The dissolution time is generally 40 to 120 minutes. During the dissolving process, use the mixer in the dissolving tank to stir, but the stirring speed should not be too fast, so as not to interrupt the molecular chain and affect the flocculation effect. Usually, the concentration is anionic or non-ionic, the high dissolved concentration is 0.5%, and the cationic concentration cannot exceed 1%. When using, dilute twice with water, and the dosage ratio is roughly: when the concentration of the suspension is 1, add 0.01 flocculant.
It is the granular anionic polyacrylamide that has more contact, and should not be added directly. It should be evenly dissolved in clean tap water, and then added in a certain proportion; it is recommended that the concentration of polyacrylamide be controlled between 0.1% and 0.3%. Generally, it is the second dilution.
When dissolving, add the anionic polyacrylamide slowly and evenly into the water tank with stirring, and the stirring speed should not be too fast (the linear speed at the end of the stirring blade should be controlled below 8 m/s), so as not to cause shearing of the anionic polyacrylamide Lower; eating too fast can also form a ball, creating a "fish eye".
The prepared polyacrylamide solution should not store cations for more than one day and anions for more than two days to avoid degradation. The dissolved solution should not come into contact with iron ions, as iron ions are catalysts that easily decompose anionic polyacrylamide. When pumping materials, it is recommended to use a diaphragm pump, vacuum pump or low pressure centrifugal pump (because the high-speed rotation of the pump vane can easily degrade the anionic polyacrylamide).