In sewage treatment, due to the complexity of water quality, it is difficult to determine the amount of polyacrylamide, but when using polyacrylamide, it must be dissolved according to the dissolution rate (0.1-0.5%) provided by the polyacrylamide manufacturer. For the specific amount of increased sewage, we need to make a small measurement to determine the specific amount of increased sewage before increasing the number of goods.
Generally speaking, under standard conditions, we use polyacrylamide to treat sewage. The consumption of raw water per ton is about (1-10 grams). Of course, it is recommended not to use this value as a reference. The specific value still needs to be measured by the demand side. Sewage treatment plants generally use polyacrylamide dehydration and squeeze, that is, the cationic polyacrylamide we often mention, and the large removal of dry mud in use can reach 5 kg. The amount of cationic polyacrylamide can be determined according to the actual situation, and this value is generally directly related to the polyacrylamide agent itself, dehydration equipment and process. Of course, in many cases, when using polyacrylamide, we need to compare which effect is good and which effect is poor. When determining how polyacrylamide treats a ton of sewage, we need to determine it based on many factors. The actual value The operation is more accurate. Here we want to remind everyone that we must pay attention to the method of dosing. Increase the polyacrylamide, should not be excessive, should not be insufficient, so as to avoid the problem of inversion in the treatment of sewage.
Polyacrylamide is one of the main agents for wastewater treatment in today's industrial field. Polyacrylamide has hundreds of specifications and models. The effect of wastewater treatment is directly linked to the selection of polyacrylamide. Wastewater treatment starts with the selection of suitable polyacrylamide. Choosing the right polyacrylamide can not only achieve the desired results, but also save a considerable amount of expenditure for the enterprise. Here is how to choose the right polyacrylamide to treat sewage!
The choice of polyacrylamide for wastewater treatment is not only based on the characteristics of the wastewater in the specific industry, but also depends on where the flocculant is added and what purpose it is used for.
Generally, when selecting inorganic flocculants, the composition and PH of wastewater should be considered, and then the most suitable one (iron-aluminum salt, silicon-aluminum salt, etc.) should be selected.
When choosing an organic flocculant (such as polyacrylamide), it is mainly to use anionic polyacrylamide, cationic polyacrylamide or non-ionic polyacrylamide. Anionic polyacrylamide is generally divided into weak anion, middle anion and strong anion according to the different degree of hydrolysis.
The selection of cations is generally used in sludge dewatering. The selection of cationic polyacrylamide is very important. Municipal sewage treatment plants generally use medium-strength cationic polyacrylamide. For sludge dewatering in paper and printing and dyeing plants, weak cations are generally selected, and medical wastewater is generally used. Choose strong cations and so on.
Each type of wastewater has its own unique characteristics. Non-ionic polyacrylamide is mainly used under weakly acidic conditions. Printing and dyeing plants use non-ionic PAM more.
In summary, all the flocculants that we just mentioned, such as polyacrylamide, polyaluminum chloride, etc., need to be determined based on experiments. In the experiment, first determine the approximate dosage and observe Flocculation sedimentation speed, calculate the treatment cost, choose economical and applicable flocculation agent
One.Polyacrylamide (APAM) for wastewater treatment in iron and steel plants is divided into powder and granular forms. The powdery and granular products have the same effect. The powdery dissolves faster, but it is more complicated than the granular production process. Polyacrylamide is a water-soluble polymer. Because its molecular chain contains a certain number of polar groups, it can absorb solid particles suspended in water, bridge between particles, or aggregate particles to form large flocs through charge neutralization. Therefore, it can accelerate the sedimentation of particles in the suspension, has a very obvious effect of speeding up the clarification of the solution and promoting filtration.
Two. Polyacrylamide use in wastewater treatment of iron and steel plants: Polyacrylamide in wastewater treatment of iron and steel plants is mainly used for flocculation, sedimentation and clarification of industrial wastewater from iron and steel plants. Polyacrylamide can also be used in electroplating plant wastewater, metallurgical wastewater, coal washing wastewater, sewage treatment, sludge dewatering, drinking water clarification and purification treatment, etc.
Three. Main technical indicators of polyacrylamide for wastewater treatment in iron and steel plants
Model Appearance Solid content (%) Molecular weight (10,000) Charge density (Mole %)
Anionic white powder ≥ 88 600-2000 10-40
Fourth, the characteristics of polyacrylamide products for wastewater treatment in iron and steel plants
1. It has good water solubility and can be completely dissolved in cold water.
2. Add a small amount of polyacrylamide products in the wastewater treatment of the iron and steel plant to receive a great flocculation effect. Generally, only 0.01~10ppm (0.01~10g/m3) needs to be added to give full play to its effect.
3. Simultaneous use of polyacrylamide products and inorganic flocculants (polyferric sulfate, polyaluminum chloride, iron salts, etc.) for wastewater treatment in steel plants can show greater effects.
Five. The use of polyacrylamide in wastewater treatment of iron and steel plants:
1. When using it, prepare a 0.1% concentration aqueous solution, and use neutral water without salt impurities.
2. When dissolving, evenly sprinkle the polyacrylamide product from the wastewater treatment of the iron and steel plant into the stirred water, and control the stirring speed at 100~300rpm. Proper heating (< 60°C) can accelerate the dissolution.
3. Adjust the PH value of the liquid to be treated, so that the polyacrylamide products in the wastewater treatment of iron and steel plants can give full play to their effects (the PH value and the dosage of this series of products are selected through experiments.)
4. When adding the polyacrylamide product solution to the wastewater treatment of the iron and steel plant, the mixing with the treated liquid should be accelerated. When the flocs appear, the stirring speed should be slowed to facilitate the growth of the flocs and accelerate the settlement.
six. Precautions for polyacrylamide in wastewater treatment of iron and steel plants:
1. The operator should wear protective equipment and wash with water after skin contact.
2. At the use site, always rinse with water to prevent slipping and injury.
3. Polyacrylamide products for wastewater treatment in steel plants should be sealed and stored in a cool and dry place.