- Correct selection method of polyacrylamide for mineral processing
- What is the degree of hydrolysis and ionic degree of polyacrylamide?
- What factors are related to the amount of polyacrylamide?
- Effect and distinction of polyacrylamide and decolorizing agent
- Causes and solutions of sludge whitening in sewage
- Application of polyacrylamide in the whole process of oil recovery
- Characteristics and application range of instant polyacrylamide
- Spray drying polyaluminum chloride -- Chinafloc-PAC
- Sludge dewatering process of polyacrylamide
- Main application of polyacrylamide (Chinafloc Series)
In the treatment of the domestic sewage, there are two types of the water flocculants: the PAM (Polyacrylamide) and the PAC (Polyaluminium Chloride). The domestic sewage is the waste water which is directly discharged by the residents in the daily life, the major component is the stool and the washing waste water. The domestic sewage figures high value content of the nitrogen, the sulfur and the phosphorus. In order to remove the large amount of the organic compounds in the water such as the cellulose, the starch, the sugar and the fat protein, it is required to use the special technic processing in the treatment.
In the treatment processing of the domestic sewage, the first step is to separate and to recover the dissolved suspending pollutants in the waste water, including the oil film and the oil droplets, by physical effect, and then, use the chemical treatment method and the biological treatment method. It is very hard to achieve the National Emission Standard by using the single treatment method in the treatment of the domestic sewage.
The effect of the flocculating agent in the chemical treatment method:
1. In the chemical treatment method, the treatment processing units which are based on the chemical reactions by adding the reagent are: the coagulation, the neutralization, the oxidation and the reduction.
2. In the coagulation process, the polyaluminium chloride (PAC) is needed to be used for the pretreatment, making the bigger sized impurities in water precipitate.
3. The micro suspending particles in the water can not be removed completely by the polyaluminium chloride (PAC), therefore the Cationic Polyacrylamide is required to be used to precipitate the fine suspending particles.
The characteristics of the domestic sewage:
From the view of the water quality and the water processing technology aspect, the urban sewage, especially the daily life waste water without the flushing drainage, has better water quality with high value organic content.
From the view of the water volume aspect, the total amount of the urban sewage is almost the same as the daily water supply, besides, the rain has the seasonal and random characteristics, both the rain and the treated water could work as the urban recycled water for the daily life.
From the view of the construction aspect, the construction work for the required equipment in the the urban sewage treatment and for the rain is much less than the works which is required for the tap water equipment.
The treatment processing of the domestic sewage is relatively simple, after the treatment, the waste water could be recycled and reused for the urban daily life.
The Anionic Polyacrylamide is usually used in the processing of the coal washing. The coal washing processing can create a large amount of waste water, the impurities in the waste water contains a large amount of the sands and the fine powder etc. The Polyaluminum Chloride and the Anionic polyacrylamide can work together to remove these sediments in the waste water.
Generally speaking, the main purpose of the coal washing is: to reduce the coal ash, to remove the impurities, to improve the coal quality, to protect the environment.
The Polyaluminium Chloride (PAC) is usually used as the coagulant and the filter aid in the coal separating plant. When the coal slurry has the serious cementation, the effect is not satisfied if only using the flocculant, therefore, it is necessary to use the coagulation first to break down the colloid of the particles, and then use the flocculant (the polyacrylmide). Sometimes in the dewatering section, the polyaluminium chloride (PAC) is also used as the filter aid in order to improve the effect of the dehydration.
In order to make the polyacrylamide to promote the rapid sedimentation of the coal slurry in the concentration tank and to ensure the qualified coal washing water and the filter slime production, which will guarantee the high efficient and high economical production, it is strongly required to select the appropriate flocculant to strengthen the treatment of the coal slurry waste water.
The function of the coal washing flotation reagent is to change the surface properties of the mineral particles, and to increase the hydrophobicity of the mineral surface which make the surface of the mineral particles more hydrophobic, that will make it more easy to make the particles attached to the bubbles and make them float, thus that will improve the flotation efficiency.
The coal washing plant always use a kind of reagent, that is the polyacylamide, however, some coal washing plant also use other dosing method due to the different design and the site factors etc., such as the mixing device etc. The dosing location factor, the pumping capacity, the property of the coal slurry and the workers’ experience in the dosing workshop is also important factors.