As we all know, China is a country with scarce water resources. Environmental protection is the key to ensure the sustainable development of the material basis. The protection of water, treatment of water pollution is an important part of environmental protection, so the application of polyacrylamide PAM in water treatment is of particular significance.
Polyacrylamide is the world's most widely used, the highest performance of organic polymer flocculants, which is also the most popular used flocculants in China currently. Polyacrylamide is mainly sold in two forms of goods, one is powder, and one is emulsion. The most commonly used is powder products as emulsion is not easy to transport and not convenient to use. There are cationic, anionic and non-ionic several types polyacrylamide, suitable for different purposes and different flocculation objects. Polyamide (PAM) amide (-CONH2) can be affinity with many substances, adsorption to form hydrogen bonds. The high molecular weight PAM forms a "bridging" between the adsorbed particles, allowing several or even dozens of particles to be joined together to produce flocs to accelerate the subsidence of the particles, making it the ideal flocculants. PAM flocculants is mainly used to deal with various wastewaters, and compared with the traditional inorganic flocculants advantages are: easy to adapt to a variety of conditions, small dosage, high efficiency, less sludge generated, post-processing easy.
Municipal sewage treatment plants and industrial wastewater treatment plants usually use polyacrylamide PAM and other flocculants flocculation clarification and purification treatment. Generally in a secondary sewage treatment plant, the amount of sludge generated by the sewage treatment is about 0.5% -1.0 % of the sludge produced by the need to dehydrate to produce clean water and high solid content of the filter cake, and reduce the weight and volume of waste sludge to improve the effectiveness of incineration and fertilizer production. Many sewage treatment plants use filter press to improve the dehydration rate, this sludge is very hydrophilic, with a negative charge, which is difficult to dehydrate. In the mechanical dehydration before the use of acrylamide polymer must be effective pretreatment to improve the sludge performance; improve the production capacity of mechanical equipment, sludge dewatering polyacrylamide PAM more and more inclined to use Cationic Flocculants products, especially acrylamide And copolymers of propylene-hydroxyethane trimethylamine chloride. Anionic polyacrylamides are also widely used, either alone or in combination with cationic polymers.
