Sludge dewatering using polyacrylamide can be divided into natural drying dehydration and mechanical dehydration. Both sludge dewatering methods have their own emphasis, and polyacrylamide is required.
Natural dry dewatering refers to the dewatering by placing the sludge in the drying square by evaporation, permeation and clearing of the liquid. This method is prone to stench and breed diseases.
Mechanical dewatering is the main method of sludge dewatering in China. The sludge is dewatered by equipment such as filter press. During the period, the polypropylene is used to treat the dewatering efficiency.
What are the methods for sludge dewatering using polyacrylamide?
The water treatment agent often used for sludge dewatering is cationic polyacrylamide, and different cationic cation polyacrylamides are selected for dehydration treatment according to different conditions of sludge. The working principle is to neutralize the negative charge in the sludge colloid by the positive charge attached to the molecular chain of the cationic polyacrylamide, accelerate the sludge agglomeration, and use the long molecular chain to entangle the sludge particles together, mainly applied to Compressed double layer action of cationic polyacrylamide and adsorption bridging.
Cationic polyacrylamide for sludge dewatering, according to the ion density, the cation-type polyacrylamide is divided into weak cations, medium cations and strong cations, which are used in practice. The higher the ion density, the stronger the effect of the negative charge on the destabilization of the sludge colloidal particles, but the molecular weight of the high ion density polyacrylamide tends to be small, and the adsorption bridging ability is weak. Therefore, the sludge quenching and tempering effects of the above three polyacrylamides are generally not much different. The type and dosage of polyacrylamide during sludge dewatering and the dryness of the mud cake after dewatering vary depending on the type of sludge. Therefore, various types of polyacrylamide products must be tested and selected.
When customers need to use cationic polyacrylamide for sludge dewatering, it is best to conduct a small test to determine which ionic degree of cationic polyacrylamide is needed. On the one hand, the use cost is reduced, and on the other hand, the use effect is enhanced.
