Polyacrylamide is widely used in many fields, but no matter which kind of water purification agent, the dosage and water purification effect are not invariable. Because the water body presents different characteristics with the change of industry, region, temperature and pH value, it is necessary to adjust the type, dosage, temperature, mixing time and sedimentation time of water purification agent according to different actual conditions. Only by combining the use characteristics of water purification agent and the actual characteristics of raw water treatment, can the maximum utility of the agent be brought into full play, the use cost be reduced, and the optimal effluent effect be obtained. Attention should be paid to the following aspects in the use of polyacrylamide

1. Dissolution temperature of reagents

The effect of temperature on the viscosity of polyacrylamide is significant. The viscosity of the solution decreases with the increase of temperature, because with the increase of temperature, the network polymer formed by the dispersed phase particles of polymer solution is easier to be destroyed, so its viscosity decreases.

2. Hydrolysis time

The results show that the viscosity of polyacrylamide solution changes with hydrolysis time. The viscosity of the solution with short hydrolysis time is lower, because the polymer has not formed network structure; the viscosity of the solution with long hydrolysis time will also decrease, because the structure of polyacrylamide in the solution is loose.

3. Molecular weight

The viscosity of polyacrylamide solution increases with the increase of polymer molecular weight. The larger the molecular weight of polymer is, the easier the chain entanglement is between molecules. When the content is low, the polymer solution has a network structure. When the content is higher, the solution is gelatinous and the viscosity of the solution is greater.

Due to the above factors, the viscosity of polyacrylamide changes greatly, so in the process of use, if the temperature of the treated water is low, the solution temperature of polyacrylamide should be increased accordingly; if the effect of high viscosity is needed, the type of polyacrylamide with high molecular weight should be selected. No matter what type of raw water, the most scientific way to use polyacrylamide is to determine the hydrolysis time by experiment.