First, the sludge traits. On the high content of organic matter sludge, the more effective flocculant is cation, the higher the organic content, the higher the degree of polymerization should be used cationic flocculant. For inorganic-based sludge, anions may be considered. The different properties of sludge directly affect the conditioning effect, scum and residual activated sludge is more difficult to dehydration, mixed sludge dewatering performance is between the two. In general, the more difficult to dehydrate the greater the amount of sludge flocculation, sludge particles small, will lead to increased flocculant consumption, sludge in the organic content and alkalinity, will lead to increased flocculant dosage. In addition, the sludge solidification rate also affects the dosage of flocculant, the higher the solidification rate of sludge, the greater the amount of flocculant used when using sludge dewatering machine.
Second, the sludge pH. Sludge pH of the hydrolysis of the product form, the same flocculant on the different pH of the sludge treatment effect is also very different. The hydrolysis of aluminum salt is greatly influenced by the pH, and the optimum pH range of the agglomeration reaction is 5 ~ 7. High iron salt conditioning agent by the degree of pH less, the best pH range of 6 to 11. Ferrous salt in the pH of 8 ~ 10 of the sludge, the solubility of the hydrolyzate can be oxidized to a lower solubility of the floc. Therefore, the choice of inorganic salt flocculant, the first to consider the specific pH of the dewatered sludge, if the pH deviation from the best range of its condensation reaction, it is best to replace the use of another. Otherwise it is necessary to consider the sludge before conditioning, add acid or alkali to adjust the sludge pH.
Third, the flocculant concentration. The concentration of flocculant not only affects the conditioning effect, but also affects the consumption of pharmaceuticals and the sludge cake yield of sludge dewatering machine, among which organic polymer flocculant effect is more significant. In general, the lower the concentration of organic polymer flocculant preparation, the less the consumption of drugs, the better the conditioning effect. But the preparation of too high or too low concentration will reduce the cake yield. While the conditioning effect of inorganic polymer flocculant is almost unaffected by the concentration of preparation. The concentration of organic polymer conditioning agent is between 0.05% and 0.1%, the concentration of ferric chloride is 10%, and the concentration of aluminum salt is 4% ~ 5%.
Fourth, the temperature of the mixed treatment solution. The temperature of the sludge directly affects the hydrolysis of the flocculant. When the temperature is low, the hydrolysis will slow down. If the temperature is below 10 ℃, the flocculation effect of the sludge dewatering machine will be obviously worse, and the conditioning effect can be improved by the method of prolonging the flocculation time. Winter temperature is low, we should pay attention to the sludge dewatering machine insulation links, not less than 15 ℃, to minimize the loss of heat in the process of sludge transport.