In sewage treatment, polyacrylamide and polyaluminum chloride are the most used flocculants. Among them, polyaluminum chloride has a single type, and it is only necessary to select different alumina contents according to the treatment needs. However, PAM is different. The single ionic type is divided into anion, cation and non-ion, and each ionic type has different specifications. So among the many PAM models, why is polyacrylamide anion used more in sewage treatment?
There are two main reasons for choosing anionic PAM to treat sewage:
1. The price is low. Compared with other ionic products, the processing cost is naturally low in actual use.
2. It has strong applicability and wide molecular weight range, which can basically meet the needs of most industrial sewage treatment and purification. The price is low, the treatment cost is low, the treatment effect is good, and the applicability is strong. Naturally, there are more choices in sewage treatment.
Anion is one of the three major ionic types of PAM, has a high molecular weight, and is a linear water-soluble polymer. The molecular weight range is between 8 million and 20 million, while the molecular weight of cations is only between 8 million and 16 million. The charge of the dissolved anion group, under the action of bridging or neutralizing the charge, causes the particles to agglomerate to form large flocs, so it can accelerate the sedimentation of the particles in the suspension, thereby forming flocs, also known as “vanadium flower”. ”, through the continuous action, the vanadium flower becomes large and dense, so as to precipitate, achieve the effect of separation of mud and water, and make the supernatant clear and transparent.
After a long-term comparison, it is found that polyacrylamide anion has a very good effect: clarification and purification, sedimentation promotion, filtration promotion, thickening and thickening, etc. 1. There are many molecular weight models, which can meet the needs of various sewage treatment, such as sand washing plants, coal washing plants, printing and dyeing plants, etc. 2. The price advantage is great. As we all know, the price of PAM is the highest in cation, followed by non-ion, and the price of anion is relatively much cheaper. Selecting anions for wastewater treatment can reduce costs. 3. The treatment effect is ideal. From the perspective of flocculation and sedimentation, anions have an irreplaceable role, and most industrial sewage contains cationically charged ions, so the effect of using anions is ideal. It is especially used in the fields of papermaking sewage treatment, sand washing sewage treatment, and coal washing sewage treatment. The particles in such sewage are mostly positive, and the molecular chain of anionic groups can play a good flocculation effect, so it has an irreplaceable role.
Post time: Apr-21-2022