PAM is the abbreviation of polyacrylamide with extremely high polymer flocculant, which is commonly used in sludge dewatering, sewage flocculation, decolorization, turbidity removal, filter aid, thickening and other purposes. The molecular weight of PAM flocculant is between 5 million and 25 million, and the commonly used models are divided into three types: cation, anion, and non-ion. Many customers have encountered in the sewage treatment when adding polyacrylamide flocculation effect is not good, today we will simply talk about the factors affecting the effect of PAM flocculation.
PAM flocculant is most commonly used in sewage treatment. Adding a small amount of polyacrylamide solution to sewage can show a strong flocculation function, but sometimes the flocculation effect is not good. This reason can be divided into the following categories:
1. PAM polyacrylamide model selection error: cationic polyacrylamide as sewage flocculation is suitable for highly toxic, containing organic sewage flocculation treatment and organic sludge dewatering process. Anionic PAM is suitable for flocculation treatment of sewage with large suspended particles, high turbidity and positive charge. Non-ionic polyacrylamide can show strong flocculation function in acidic water quality due to the activity of amide groups on the side chain of molecules without ionic functional groups.
The ratio of the dissolution of the 2. PAM polyacrylamide: the dissolution ratio of anionic PAM and non-ionic polyacrylamide is 1‰, and the best dissolution ratio of cationic polyacrylamide is 2.
3. PAM polyacrylamide dissolution water temperature: PAM is white crystalline particles, which need to be dissolved with clean tap water when used. The general dissolution time is 60 minutes, but the dissolution time in autumn and winter will increase generally about 2 hours. If the dissolution water temperature is increased, the dissolution time can be shortened. The general temperature is controlled below 60 ℃, and it is recommended to be between 40-50 ℃.
Dosage of 4. flocculant polyacrylamide: the dosage is generally different according to different water quality. If the dosage is less than the flocculation effect in sewage, the viscous liquid will occur if the dosage is more. Generally, it is recommended to do beaker flocculation experiment before using the machine. The best dosage of flocculant is that the flocculant is completely adsorbed on the surface of solid particles, and the sedimentation velocity of the flocs reaches the maximum value. The optimum dosage varies with the ionic nature of the flocculant, the molecular weight, and the pH of the suspension, and can be determined experimentally. When the amount of flocculant exceeds the optimum, the flocculation effect decreases.
5. the effect of flocculant molecular weight on flocculation: the higher the molecular weight of flocculant, the better the flocculation effect. However, the molecular weight is too large, it is difficult to dissolve and the manufacturing cost is also high. Commonly used molecular weights are 300-18 million.
6. the effect of stirring speed on flocculation: stirring can make the flocculant evenly dispersed into the suspension, to achieve efficient flocculation. But the stirring is too intense, will make the formation of the flocculant fragmentation, thus increasing the consumption of flocculant, flocculation effect is relatively speaking is reduced. Therefore, only appropriate stirring can be carried out during the flocculation treatment.