Mar 20

Refrigerated sewage and sludge are often decompressed by decanter centrifuge. During the process, flocculants may be added to improve the treatment effect of sewage and sludge. Which one should be used and what are the principles of dosage, generally. It can be analyzed from the aspects of sludge properties and pH value.

Decanter centrifuge-GN

First, the properties of sewage and sludge. The difference in its properties directly affects the sludge dehydration effect: Generally speaking, the more difficult the sludge is to dehydrate, the larger the amount of flocculant used. The smaller the sludge particles, the greater the amount of flocculant. The higher the organic content and alkalinity in the sludge, the greater the amount of flocculant used. Cationic organic polymers are more effective in treating sludge with high organic content. Cationic organic polymers with high organic content are preferred. For sludge mainly composed of inorganic materials, anionic organic polymer flocculants can be considered. In addition, the solid content of the sludge also affects the dosage. Generally, the higher the solid content of sludge, the greater the amount of use.

Second, the pH value of sewage, sludge. The pH of the sludge determines the form of the hydrolysate of the inorganic salts. The same flocculant is used for sludge with different pH values, and the conditioning effect is also very different. The hydrolysis reaction of aluminum salt is greatly affected by the pH value, and the optimal pH value of the agglomeration reaction is 5-7. High iron salts are less affected by pH, and the optimal pH range is 6-11. In the sludge with a pH value of 8-10, the ferrous salt with higher solubility can be oxidized to Fe (0H), floc with lower solubility.

GN-Decanter Centrifuge

Therefore, when selecting an inorganic salt, the specific pH value of the dewatered sludge must be considered first. If the pH value deviates from the optimal range of its condensation reaction, it is best to use another one. Otherwise, it is necessary to consider adding the acid or alkali to adjust the pH of the sludge before using the decanter centrifuge to treat the sludge.

written by Decanter Centrifuge

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