How to use polyacrylamide flocculants?

How to use polyacrylamide flocculants?

Polyacrylamide flocculants are high molecular weight organic compounds, most of which have molecular weights of more than several million,
and some are even close to 20 million. Therefore, their dissolution methods are very different from inorganic small molecular iron salt and
aluminum salt coagulants. Generally speaking, the following principles should be followed:

1. Powdered polyacrylamide flocculants cannot be added directly to sewage. It must be dissolved in water before use, and its aqueous solution
should be used to treat sewage.

2. The water used to dissolve powdered polymers should be clean water (such as tap water), not sewage. Water at room temperature is sufficient,
and generally does not need to be heated. When the water temperature is below 5, the dissolution is very slow. The dissolution speed increases
with increasing water temperature, but above 50 will accelerate the degradation of the polymer and affect the use effect. Generally, tap water is
suitable for preparing polymer solutions. Strong acid, strong alkali, and high salt water are not suitable for preparation.

3. For the selection of polymer solution concentration, our company recommends 0.1% to 0.3%, that is, add 1 to 3 grams of polymer powder
to 1 liter of water.

The following factors should be considered when selecting the concentration:

If the preparation tank is small and the daily dosage is large, it is recommended to prepare a slightly concentrated solution (such as 0.3%);

When the molecular weight of the polymer is very high, it is recommended to prepare a slightly dilute solution (such as 0.1%);

When the polymer solution is added to the sewage, if the dispersion condition is not good due to equipment reasons, it is recommended toZ
 prepare a slightly dilute solution.

In short, if the polymer concentration is too high, the agitator motor will be overloaded, and the dispersion condition will be poor after entering
the sewage, affecting the use effect. Preparing a dilute solution will help improve the use effect.

4. Do not transfer the prepared solution with a centrifugal pump to avoid shear degradation of the polymer caused by the high-speed rotating blades.

The specific method of preparation is as follows: add a certain amount of clean water to a container (such as a beaker in a laboratory, a preparation
 tank in a factory), calculate the required amount of powdered polymer according to the amount of clean water and concentration, and weigh the
polymer; turn on the electric stirrer to stir the clean water into a vortex. The linear speed at the end of the stirrer blade should not exceed 8 m/s
to avoid polymer degradation; but it should not be too slow to avoid polymer particles floating on the water surface, or sinking and agglomerating
 in the water.

Slowly sprinkle the polymer into the vortex of water until it is finished. Note that the polymer particles should not stick to each other or agglomerate
 after entering the water. Then stir for a while to fully dissolve the polymer particles, and finally become a uniform, transparent, viscous solution
without visible lumps.

The stirring time is determined as follows:

A. In summer when the water temperature is high, anionic and cationic polymers need to be stirred for about 1 hour, and nonionic polymers need
to be stirred for about 2 hours;

B. In winter when the water temperature is low, anionic and cationic polymers need to be stirred for about 1.5 hours, and nonionic polymers need
 to be stirred for about 3 hours;

Also, the higher the preparation concentration, the faster the polymer dissolves. Uneven or insufficient dissolution will affect the use effect.