The polyacrylamide flocculants produced by our company are high-molecular-weight organic compounds, with molecular weights mostly in the millions and some even approaching 20 million. Therefore, their dissolution methods differ significantly from those of inorganic small-molecule iron and aluminum salt coagulants. Generally, the following principles should be followed:

1. Polyacrylamide flocculants cannot be directly added to wastewater. They must be dissolved in water before use, and the resulting aqueous solution should be used to treat the wastewater.
2. The water used to dissolve the polymer should be clean water (such as tap water), not wastewater. Room temperature water is sufficient; heating is generally not required. Dissolution is very slow below 5°C, and the dissolution rate increases with water temperature, but temperatures above 40°C will accelerate polymer degradation, affecting the effectiveness. Generally, tap water is suitable for preparing polymer solutions; strong acid, strong alkali, and high-salt water are not suitable.
3. Our company recommends a polymer solution concentration ratio of 0.1% to 0.3%, that is, 1-3g of polymer powder per liter of water. The following factors should be considered when selecting the concentration: For small preparation tanks with large daily dosages, a slightly higher concentration (e.g., 0.3%) is recommended; for high polymer molecular weights, a slightly lower concentration (e.g., 0.1%) is recommended; if the polymer solution does not disperse well in wastewater due to equipment limitations, a slightly lower concentration is recommended. In short, excessive polymer concentration will overload the agitator motor and result in poor dispersion in the wastewater, affecting the effectiveness.
4. Do not use a centrifugal pump to transfer the prepared solution, as the high-speed rotating blades may cause shear degradation of the polymer.

The specific preparation method is as follows: Add a certain amount of water to a container (e.g., a laboratory beaker or a factory preparation tank). Calculate the required amount of powdered polymer based on the water volume and concentration, and weigh the polymer. Turn on the electric agitator to create a vortex in the water. The linear velocity of the agitator blade tip should not exceed 8 m/s to avoid polymer degradation; however, it should not be too slow to prevent polymer particles from floating on the surface or sinking and clumping.

Slowly sprinkle the polymer into the swirling water until all particles are added. Ensure the polymer particles do not clump together after entering the water. Stir for a period to allow the polymer particles to fully dissolve, resulting in a homogeneous, transparent, viscous solution without visible clumps. The stirring time should be determined as follows:

A: In summer when water temperatures are high, anionic and cationic polymers require approximately 1 hour of stirring, while nonionic polymers require approximately 2 hours of stirring

B: In winter when water temperatures are low, anionic and cationic polymers require approximately 1.5 hours of stirring, while nonionic polymers require approximately 3 hours of stirring;

Iron ions are catalysts that cause the chemical degradation of all polyacrylamides. Therefore, when preparing, transferring, and storing polyacrylamide solutions, the introduction of iron ions should be minimized. Equipment in contact with the solution is best made of stainless steel, plastic, fiberglass, or carbon steel with a resin coating.