Alcohol is a widely used chemical product and a clean fuel. Alcohol production methods include fermentation and synthesis. In the production process of alcohol, a large amount of wastewater will be generated. Because alcohol wastewater contains a large amount of organic matter, it needs to undergo air flotation treatment and sludge drying treatment. At this time, polyacrylamide flocculant is needed.
During the fermentation of alcohol, a large amount of yeast is produced in the fermentation mash. After solid-liquid separation, the solids in the wastewater are concentrated and separated, and the wastewater is subjected to secondary fermentation to concentrate and separate the yeast. The fermentation wastewater using waste molasses as the main raw material is brownish black. The yeast wastewater COD separated from the yeast liquid fermentation tank can reach a COD of 30,000-7000 mg∕L or even more than 100,000 mg∕L, with a PH value of about 6.0-7.0. Wastewater also contains about 0.5% dry matter, the main components are yeast protein, cellulose, colloidal substances, and nutrients in underutilized waste sugar.
Characteristics of alcohol wastewater:
① The content of suspended solids (SS) is high, with an average content of 40,000 mg/L;
② The water temperature is high, and the temperature of the alcohol wastewater discharged from the bottom of the distillation kettle reaches 100℃;
③High concentration, COD in alcohol wastewater is as high as 20,000-70,000 mg/L, including suspended solids, soluble COD and colloids, organic matter accounts for 93%-94%, inorganic matter accounts for 6%-7%, the main component of organic matter is carbohydrates , Followed by nitrogen-containing compounds, in addition to 500mg/L organic acids;
④The wastewater contains about 500mg/L of organic acid, which is acidic. It needs to add alkali or sludge to return in the initial operation. After the operation is stable, the system has sufficient buffering capacity, so there is no need to add alkali or return.
In general, Polyacrylamide for alcohol plant is used in the air treatment of raw water and the drying of sludge in the wastewater treatment of alcohol plants.
Air floatation treatment: it can treat suspended matter in wastewater, the main function is to adsorb and bridge the suspended matter to flocculate into larger particles, reduce resistance and accelerate the rise of suspended matter, so as to achieve the purpose of wastewater treatment.
Sludge drying treatment: The natural concentration of sludge will still have a high water content. Use a mechanical filter press to ensure that the sludge has sufficient water drainage and a certain size of particle size. In this process, it is necessary to add Rongsheng cationic polyacrylamide.
The application of polyacrylamide flocculant in the treatment of alcohol wastewater is extremely wide, because the amide group (-CONH2) of polyacrylamide can be affinity with many substances and form hydrogen bonds by adsorption. The high-molecular-weight PAM forms a "bridge" between the adsorbed particles, connecting several or even dozens of particles together, generating flocs and accelerating particle sinking. This makes it a flocculant in the field of water treatment. PAM is mainly used to treat water and various wastewater. In the process of treating wastewater from alcohol plants, the important role of polyacrylamide is to effectively absorb and adsorb the internal dirt molecules when treating alcohol wastewater, so as to detach these flocculated substances from the water and prevent them from appearing on the equipment. The phenomenon of scaling. Therefore, the role of polyacrylamide in the treatment of alcohol wastewater is very large, while other flocculants have no such effect. When using polyacrylamide in the treatment of wastewater from alcohol plants, some customers often do not know how to use the amount of polyacrylamide in the treatment of wastewater, so it will cause a small amount or a large amount. In fact, the amount of polyacrylamide used in each water treatment process is not high. The user can determine the amount of polyacrylamide additive added according to the total amount of water treatment, and adjust it according to the ratio, so that it will not appear. Put more and less. Polyacrylamide for alcohol plant is a lot of polymer organic synthetic flocculants currently used in the treatment of alcohol wastewater, and it is also a widely used flocculant in my country. Polyacrylamide is mainly sold in two forms, one is powder and the other is colloid. Colloids are not easy to transport and inconvenient to use. Powdered products are commonly used. Polyacrylamide has several types of cation, anion and non-ion, suitable for different uses and different flocculation objects.