What is anionic polyacrylamide?
Anionic polyacrylamide (APAM) is a water-soluble polymer, which is mainly used for flocculation, sedimentation and clarification of various industrial wastewater, such as wastewater treatment and sludge dewatering of iron and steel plant, electroplating plant, metallurgical wastewater and coal washing wastewater. It can also be used for drinking water clarification and purification. Because its molecular chain contains a certain number of polar groups, it can bridge the particles by adsorbing the solid particles suspended in water or condense the particles to form large flocs through charge neutralization. Therefore, it can accelerate the sedimentation of particles in the suspension, obviously accelerate the clarification of solution and promote filtration.
What effect does anionic polyacrylamide have?
1. Clarification and purification;
2. Sedimentation promoting effect;
3. Filtration promotion;
4. Thickening and other functions.
It can fully meet the requirements of various fields in waste liquid treatment, sludge concentration and dehydration, beneficiation, coal washing, papermaking, etc.
Anionic polyacrylamide treatment scheme for coal washing wastewater:
Generally, the treatment process of "cyclone thickener filter press (slime sedimentation tank)" is adopted for the treatment of slime water in coal preparation plant. In general, it is the purchase of high molecular flocculant (polyacrylamide). High molecular flocculant contacts with coal slime particles or coal slime colloids, neutralizes the electricity of coal slime surface, reduces surface energy, and makes coal slime particles agglomerate and precipitate. The molecular weight of polyacrylamide is generally between one million. Flocculants with different molecular weight should be selected for coal slurry water with different particle size composition. Polyacrylamide can be divided into anionic polyacrylamide, cationic polyacrylamide and non-ionic polyacrylamide. When using polyacrylamide for water treatment, it is necessary to ensure that the type is consistent with the pH value of slime water. Anionic polyacrylamide is suitable for alkaline slime water, cationic polyacrylamide is suitable for acidic slime water, and anionic and cationic polyacrylamide are used together, so the flocculation and sedimentation effect of slime water is better.
Main applications and uses of anionic polyacrylamide
1. Used in textile, printing and dyeing industry. Polyacrylamide is used as sizing agent and finishing agent for fabric treatment, and can produce a soft, wrinkle proof and mold proof protective layer. Using its strong hygroscopicity, it can reduce the breaking rate of spinning yarn. Polyacrylamide as post-treatment agent can prevent static electricity and flame retardant of fabric. When used as printing and dyeing auxiliaries, polyacrylamide can make the product have high adhesion fastness and high brightness. It can also be used as a non silicon polymer stabilizer for bleaching.
2. It is mainly used as flocculant: for the sewage with coarse suspended particles, high concentration, positive charge of particles and neutral or alkaline pH value of water, the molecular chain of anionic polyacrylamide contains a certain amount of polar groups, which can adsorb the suspended solid particles in water, bridging between particles to form large flocs. Therefore, it accelerates the sedimentation of particles in the suspension, has a very obvious effect of accelerating the clarification of the solution and promoting filtration. The product is widely used in the treatment of chemical industry wastewater and waste liquid and municipal sewage treatment. Tap water industry, purification and sedimentation of high turbidity water, coal washing, beneficiation, metallurgy, iron and steel industry, zinc, aluminum processing industry, electronic industry and other water treatment.
3. It is widely used in petroleum industry, oil production, drilling mud and waste mud treatment, preventing water channeling, reducing friction, enhancing oil recovery and tertiary oil recovery.
4. It is used in paper industry. One is to improve the retention rate of fillers and pigments. To reduce the loss of raw materials and environmental pollution; The second is to improve the strength of the paper (including dry strength and wet strength). In addition, the use of PAM can also improve the tear resistance and porosity of the paper to improve the visual and printing performance. It is also used in food and tea packaging paper.
5. Other industries, food industry, are used for sugarcane juice clarification and syrup phosphorus floating extraction in the production of sugarcane sugar and beet sugar. Enzyme preparation fermentation broth flocculation clarification industry is also used for the recovery of feed protein with stable quality and good performance. The recovered protein powder has no adverse effects on the survival rate, weight gain and egg production of chickens, synthetic resin coating, water plugging of civil grouting materials, building materials industry, improvement of cement quality, adhesives in construction industry, joint repair and water plugging agent, soil improvement, electroplating industry Printing and dyeing industry, etc.
Application of anionic polyacrylamide in industrial wastewater treatment
Anionic polyacrylamide is used in urban and industrial wastewater treatment to improve the removal effect of suspended solids, BOD and phosphate in wastewater. When 0.25mg/l hydrolyzed polyacrylamide is added to the primary wastewater sedimentation tank, the removal rates of suspended solids and BOD can be increased to 66% and 23% respectively; By adding 0.3mg/l anionic polyacrylamide to the secondary wastewater treatment sedimentation tank, the removal rates of suspended solids and BOD can be increased to 87% and 91% respectively, while the phosphorus removal effect can be increased from 35% to 91%. In the treatment of drinking water and domestic wastewater, it is used for surface clarification, clarification of flushing wastewater and filtrate adjustment.
Treatment of mining wastewater by anionic polyacrylamide
In mining, it is used for coal washing water clarification and flotation tailings, clean coal filtration, tailings (slag) dehydration, flotation tailings clarification, concentrate thickening and filtration, potash hot melt and flotation processing liquid clarification, fluorite and barite flotation tailings clarification, raw salt water for salt processing, sludge dewatering clarification and phosphate ore recovery water treatment.
Application of anionic polyacrylamide in metal manufacturing industry
In the foundry and metal manufacturing industry, it is used for the purification of open hearth gas washing water, the clarification of waste water from powder metallurgy plant and pickling plant, the purification of electrolyte and the clarification of electroplating waste liquid.