Polyacrylamide can meet the needs of individual particles of a high molecular weight flocculant may become unstable to promote flocculation and electric charge through the surface of the colloidal particles. Then the particles are adsorbed polymer flocculation, which play a reactive functional group bridging between the particles, and then flocculation to form larger floc. They are not only able to meet these basic functions, and in order to meet the different uses to maximize the effect and prepare the nonionic, anionic substance use and high molecular weight cationic flocculant flocculation polymerization.
1. Choose polymer flocculant
(1) polymer flocculant effect
Polymer flocculant effect of raw water to be treated according to the state vary. Suspended solids in raw water species, size, concentration and PH, etc. will vary depending on water quality. Another thing to note is that these conditions will usually continue to change. It is well known stirring conditions also affect the state of floc formation. Therefore, to obtain the best results, we need to adjust the PH value and stirring. High molecular weight polymer flocculation need to use will vary flocculation and sedimentation, pressurized flotation, sludge dewatering and other processing purposes are different. In order to choose the best flocculant, the user must take into account these factors and make the actual conditions very similar to the selected test.
(2) Test Method
Test procedure due to different ways of processing and vary. However, under normal conditions, the raw water to be treated is poured into a graduated cylinder and allowed to stand for one hour. If most of the sludge has been precipitated, the molecular weight may be used alone flocculating polymer processing. Using a representative anionic, nonionic and cationic polymer flocculant started experimenting. Select flocculant can generate a stable floc. Its distinction anionic or cationic ion. Then by comparing the weak, medium and strong anion and cation to determine the selection of the optimal type of flocculant. Determining the appropriate coagulant type, choose two to three kinds of products from the type. Determine the optimal dose of the product to produce the best sedimentation velocity, transparency and dewatering.
(3) used in combination with other chemicals if you are using a high molecular weight flocculant alone failed to produce the expected results, the method may be through with aluminum sulfate, poly aluminum chloride and other inorganic flocculants used in combination to improve its effectiveness. In addition, depending on the type of sludge, a high molecular weight cationic coagulant instead of inorganic flocculants may produce better results. When adding these chemicals, the inorganic coagulant is usually added first and stirred, then mixed polymer flocculant.
2, a high molecular weight flocculant is dissolved
(1) highly dispersed and dissolved using an automatic device
Flocculant must be dispersed and dissolved careful to avoid rapid dissolving the powder surface caused by the interaction between the particles adhere, resulting in failure to dissolve the particles inside "fish eye." Thus, the usual practice is to use various types of dispersing a dissolver. If you do not use powder dispersion dissolver should follow these steps to dissolve operation.
(2) different dispersion dissolver
Add water to dissolve half tank volume.
Stirring with a stirrer, the stirring weighed flocculant along the edge of the vortex generating calm and quickly poured. Before the viscosity of the solution increases, flocculants thoroughly mixed with the solvent is very important. If the viscosity of the solution too, will produce agglomeration. Water was added to the specified location, and adjusted to a specific concentration. Stirring is continued until a high molecular weight flocculating polymer is completely dissolved.
(3) dispersing and dissolving flocculant should pay attention to the project
Water polyacrylamide dissolution time according to the following conditions, the dissolution time required will vary flocculant:
a high molecular weight polymeric flocculation type body;
b dissolved coagulant used in water quality;
c temperature;
d. mixing efficiency.
However, most of the flocculants usually takes about one hour stirring time to fully dissolve the powder. Flocculant mixing inadequate or agglomeration may affect the performance of flocculants, and may even produce deposition and blocking pipes and pumps.
Water polyacrylamide stirring speed
Ideal rotation speed stirring speed of 200 to 400 revolutions per minute. We do not recommend using not reduce motor rotation speed, high-speed blender. Because it may damage the flocculant molecules. For a volume of 1 to 2 m3 mixing tank, which ideally should be a stirrer 1 horsepower motor power.
Water polyacrylamide dissolution rate
Anionic and non-ionic flocculants are usually dissolved in a concentration of 0.1% of the solvent, the cationic flocculants can be dissolved in a concentration of 0.2% solvent. May be slightly higher concentration begins to dissolve, then diluted flocculant mixture immediately before use.