Problems Needing Attention of Polyacrylamide in Sludge Dewatering Machine

The problem that polyacrylamide needs to be paid attention to in the sludge dewatering machine is that when the sludge is treated by the sludge dewatering machine, a flocculant is generally added to achieve a better treatment effect.

1. Sludge properties
For sludge with high organic content, the more effective flocculant is cationic, and the higher the organic content, it is recommended to use cationic polyacrylamide with higher degree of polymerization. For inorganic-based sludge, anionic polyacrylamide can be considered. The difference in sludge properties directly affects the conditioning effect, while scum and excess activated sludge are more difficult to dewater, and the dewatering performance of mixed sludge is in between. Generally speaking, the more difficult to dehydrate the sludge, the greater the flocculant dosage, and the finer sludge particles will lead to an increase in the consumption of flocculants. The higher the organic content and alkalinity in the sludge, the higher the amount of flocculants will also be. . In addition, the solid content of sludge also affects the dosage of flocculant. Generally, the higher the solid content of sludge, the greater the dosage of flocculant when using the sludge dehydrator.

2. Sludge pH
The pH of the sludge determines the form of the hydrolyzed product, and the same flocculant has different treatment effects on sludge with different pH. The hydrolysis reaction of aluminum salt is greatly affected by the pH value, and the optimal pH range for the coagulation reaction is 5-7. The high iron salt conditioner is less affected by the pH value, and the optimal pH range is 6-11. In the sludge with a pH of 8-10, the hydrolyzate with higher solubility of ferrous salt can be oxidized into flocs with lower solubility. Therefore, when choosing an inorganic salt flocculant, the specific pH of the dewatered sludge must first be considered. If the pH deviates from the optimal range of its coagulation reaction, it is recommended to use another one. Otherwise, it is necessary to consider adding acid or alkali to adjust the pH of the sludge before conditioning the sludge.

3. Concentration of flocculant
The preparation concentration of flocculant not only affects the conditioning effect, but also affects the consumption of chemicals and the output rate of mud cake of sludge dewatering machine, among which the organic polymer flocculant PAM polyacrylamide has a more significant effect. Generally speaking, the lower the concentration of the organic polymer flocculant is, the less the agent consumption is, and the better the conditioning effect is. However, if the concentration is too high or too low, the mud cake yield will be reduced. However, the conditioning effect of inorganic polymer flocculants is hardly affected by the preparation concentration. The concentration of organic polymer conditioner is prepared in O. 05%～O. 1% is more suitable, the concentration of ferric chloride is 10% is better, and the concentration of aluminum salt is 4%-5% is more suitable.

4. The temperature of the mixed treatment liquid
The temperature of the sludge directly affects the hydrolysis of the flocculant, and when the temperature is low, the hydrolysis will slow down. If the temperature is lower than 10°C, the flocculation effect of the sludge dewatering machine will be significantly worse, and the conditioning effect can be improved by properly extending the flocculation time. When the temperature is low in winter, attention should be paid to the heat preservation of the sludge dewatering machine, not lower than 15°C, to minimize heat loss during sludge transportation.
(The data in this article are general estimates and are for reference only, and the specific usage can be determined according to the test.)