Blog
29
2021
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01
Printing and dyeing factory special polyacrylamide use matters needing attention
In recent years, the environmental protection department has been very strict in the inspection of drainage. Therefore, many companies cannot take it lightly. They must strengthen the supervision of emission standards to avoid errors. Today we will mainly learn about the water treatment application in the special polyacrylamide for printing and dyeing plants.
The functions of special polyacrylamide in printing and dyeing factories: in the textile industry, polyacrylamide flocculant is used as a sizing agent and finishing agent for fabric post-treatment, which can produce a soft, wrinkle-resistant and mildew-proof protective layer; polyacrylamide flocculant can be used as a post-treatment agent to prevent static electricity and flame retardancy of fabrics; when used as a printing and dyeing auxiliary, it can make the product have high adhesion fastness and high brightness, and can also be used as a bleached non-silicon polymer stabilizer; this is the key point of efficient purification of printing and dyeing and textile industry wastewater discharge.
In addition, the characteristics of printing and dyeing wastewater are very obvious. Due to the large amount of water in printing and dyeing wastewater, 100-200 tons of water are consumed per ton of textiles in the printing and dyeing process, of which 80-90% is wastewater. Textile printing and dyeing wastewater has the characteristics of large water volume, high content of organic pollutants, large alkalinity, and large changes in water quality. It is also one of the industrial wastewater that is difficult to treat. The waste water contains dyes, sizing agents, additives, oils, acids and alkalis as well as fibers, impurities, sand substances, inorganic salts, etc.
For the coagulation treatment of printing and dyeing wastewater, the key is to select the appropriate polyacrylamide flocculant, the regular flocculants suitable for printing and dyeing wastewater treatment mainly include aluminum sulfate, ferric sulfate and ferric chloride in the early stage, and cationic polyacrylamide in the later stage, these flocculants are effective for treating some non-water-soluble dye wastewater, such as disperse dyes, vat dyes, sulfur dyes, chemical oxygen demand and chroma removal rates are high.
Before use, dissolve the solid particles in an aqueous solution with a concentration of 1 ‰-5 ‰ in order to play a role quickly. When administering the medicine, a step-by-step method should be adopted, and it should be slowly put into the water and evenly dissolved in the water. When adding the dissolving liquid, usually add about 0.5 ‰ to 1 ‰ of the aqueous solution, but in the case of high suspension concentration, high viscosity, it is recommended to further dilute the aqueous solution to 0.1 ‰, will be easy to mix and give full play to the effect.
Because the molecular weight of cationic polyacrylamide is lower than that of anionic polyacrylamide, and the viscosity is lower than that of anionic polyacrylamide. Therefore, the concentration standard of the ratio of cationic polyacrylamide and non-ionic polyacrylamide is slightly higher than that of anionic polyacrylamide.
At the same time, it should be noted that when preparing the aqueous solution of polyacrylamide, it should be carried out in enamel, galvanized, aluminum or plastic buckets, not in iron containers. When dissolving, pay attention to evenly under stirring and heating measures, slowly add the product to the dissolver to avoid curing, prepare the solution at a suitable temperature, and avoid excessive mechanical shear for a long time, the speed of the stirrer is 60-200 r/min minutes, otherwise it will cause polymer degradation and affect the use effect.
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