Polyacrylamide for sludge dewatering
1. The dehydrating agent suitable for the nature of the sludge and the type of dehydrator should be selected. (Generally choose 40-60 ion degree cationic polyacrylamide)
2. The quality and changes of the treated sludge should be understood.
3. Know the dissolution and storage of polyacrylamide dehydrating agent.
4. Pay attention to the injection point, reaction conditions, and dosage of polyacrylamide dehydrating agent.
The nature and treatment method of sludge and the sludge treatment process
The sludge treatment process is roughly divided into:
(2) Stabilization (anaerobic digestion treatment of sewage sludge)
(3) Pre-treatment (adding medicine, heat, freezing treatment, etc.)
(5) Drying and burning
(6) Six processes including processing and utilization
Polyacrylamide for sludge dewatering
The common process is as follows:
Using gravity concentration, the SS concentration of raw mud can be concentrated from 1% to 2~3%. Recently, in order to further increase the concentration, pressurized flotation and centrifugal separators are used.
The anaerobic digestion of sewage sludge (raw sludge) can reduce the volume through the decomposition of organic matter and has the effect of killing pathogens.
Generally use polymer polyacrylamide dehydrating agent or ferric chloride and slaked lime for pretreatment.
Polymer polyacrylamide dehydrating agent is suitable for centrifugal dehydrators that require the formation of coarse flocs, that is, belt pressure dehydrators. Vacuum dehydrator and filter press can be applied to ferric chloride and slaked lime, but it can also be treated with polymer polyacrylamide dehydrating agent.
4. Dewatering of sludge
In the treatment of surplus sludge, the proportion of belt presses and centrifugal dehydrators is increasing in recent years. Centrifugal dehydrators are mostly used in fecal sludge treatment. However, belt presses are also increasing. From the perspective of current and future development, it is hoped to reduce the moisture content without increasing the ash content in the filter cake. It is necessary to pay attention to the use of belt pressure type dehydrators and filter presses. The polymer dehydrator.
The winery uses plants as raw materials, and the sewage is characterized by high COD values. Because the wastewater contains a large part of organic matter, the use of cations can quickly remove suspended solids. Colleagues reduce the COD content.
Industrial waste water includes production waste water and production sewage, which refers to waste water and waste liquid generated in the industrial production process, which contains industrial production materials, intermediate products, by-products and pollutants generated in the production process with the loss of water. Water discharged during production. Industrial wastewater treatment polyacrylamide PAM is used as an flocculation agent for wastewater treatment, which is an important aspect of water treatment.
Polyacrylamide products are mainly used as coagulant or flocculant in the treatment of industrial wastewater. Because its molecular chain contains a certain amount of polar genes, it can adsorb solid particles suspended in water, so that bridges between the particles form large flocs. It can accelerate the sedimentation of particles in suspension, and has obvious effects of accelerating the clarification of solution and promoting filtration. It is widely used in the treatment of wastewater and waste liquid in chemical industry.
Generally, the first stage treatment of sewage (air floatation or sedimentation) is combined with inorganic flocculant (polyaluminum chloride PAC) and organic polymer flocculant (polyacrylamide PAM), while the latter stage treatment is sludge dehydration, using organic polymer Flocculant (cationic polyacrylamide) is used as sludge dewatering agent. Anion polyacrylamide is also selected for the dewatering of individual sewage sludge. This should be further determined according to the actual situation of each plant.
In short, the application of Industrial wastewater treatment polyacrylamide in the water treatment industry mainly includes raw water treatment, sewage treatment and industrial water treatment. In raw water treatment, polyacrylamide is used in conjunction with activated carbon, etc. It can be used for the aggregation and clarification of suspended particles in domestic water; in sewage treatment. Polyacrylamide can be used for sludge dewatering; in industrial water treatment, polyacrylamide is mainly used as a formulation agent. In the raw water treatment, the organic flocculant polyacrylamide is used to replace the inorganic flocculant. Even if the sedimentation tank is not modified, the water purification capacity can be increased by more than 20%.
Therefore, many large and medium-sized cities currently use polyacrylamide as a supplement when the water supply is tight or the water quality is poor. Industrial wastewater treatment, especially for suspended particles, coarser, high concentration, particles with positive charge, PH value of water is neutral or alkaline sewage, steel plant wastewater, electroplating plant wastewater, metallurgical wastewater, coal washing wastewater and other wastewater treatment , The effect is recommended. In sewage treatment, the use of polyacrylamide can increase the utilization rate of water recycling.