Two types of polymers are available on the market: emulsion polymers and dry polymers. These two products require separate instructions. However, some parameters remain applicable to both types of solutions. For example, the recommended temperature for mixing with water should not exceed 40°C; otherwise, there is a risk of damaging the polymer chains. Therefore, temperate waters are considered ideal. The pH of this solution must remain close to neutral.
This type of polymer, which is already in liquid form, only requires a dilution system. Once the desired concentration is reached, that is, between 2.5 g/L and 10 g/L, the solution can be used immediately. The emulsion solution equipment is generally less expensive than dry polymer preparation systems. However, the higher operating costs of this type of polymer should not be overlooked because of the lower percentage of active products in emulsions compared to dry polymers. In the event of a spill, don’t try to clean up the emulsion with water, as the emulsion is oil-based. Instead, use an absorbent such as bentonite, sand, or litter to clean up the spill safely and effectively. Using the right cleaning product will prevent the spill area from becoming slippery.
As mentioned above, the setups allowing the dissolution of dry polymers generate higher capital costs due to the complexity of the mechanism. The mechanical agitation, hydraulic shear, and wetting processes involved in the solution must be designed to obtain an optimal amount of active polymer in the solution. It is possible to carry out the dissolution without an automated system, but it is important to create an efficient vortex between water and the polymer to generate a homogeneous solution.
Therefore, the use of a wetting cone is recommended. The main difficulty encountered during this preparation is the creation of “Fish eyes,” i.e., the formation of clumps of polymer powder that do not solubilize in water. Appropriate equipment can tackle this problem. As the percentage of active agents in the powdered polymer is significantly higher than that in the emulsion (100% for dry versus maximum 50% for emulsions), the concentration of the polymer solution between 2 and 5 g/L is generally sufficient to achieve good flocculation. It should also be noted that this polymer solution requires an hour of maturation before it can effectively perform its functions. In addition, make sure you wear appropriate respiratory protection to prevent inhalation of polymer dust.
Precautions according to the water used
Some industries do not use water from the municipality but rather water from a well or recycled by their own treatment system. The use of these streams of water can sometimes promote bacterial growth in the polymer solution tank since more contamination sources are present compared to water provided by the city. The solution of dry polymers is more at risk for this type of problem because it requires a maturation tank, where the solution can be stored for a few days. In addition, if the recycled water from the treatment system is used, the pH must be neutral and stable. Therefore, we recommend being more alert to the appearance of biofilms in your system.