- The main application of super absorbent polymer
- 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
Only when the PH value is in a certain range, the polycarylamide can work for the best result. To achieve the good water treatment effect, the choice of the appropriate PH value range is very important. The PH value will have a great influence on the treatment effect.
The polyacrylamide has a wide model range, the most common models are the anionic polyacrylamide, the cationic polyacrylamide and the nonionic polyacrylamide.
The effective PH value is different to different types of polyacrylamide, so in the selection of the polyacrylamide, the influence of the PH value to the polyacrylamide must be considered. The physical method and the chemical method in the treatment of the oily waste water by the polyacrylamide include the coagulation mothod, the air flotation mothod, the adsorption method, the magnetic adsorption method and the electrochemical method etc., among which the flotation and the coagulation process is more popular.
The polyacrylamide suitable in different PH value:
The effective PH value range to the anionic polyacrylamide is 5 ~ 14, the effect is good in the treatment of the weak acid, the neutral and the alkaline water.
The effective PH value range to the cationic polyacrylamide is 7 ~ 14, the effect is good in the treatment of the neutral and alkaline water.
The effective PH value range to the nonionic polyacrylamide is 1 ~ 8, the effect is good in the treatment of the neutral and acid water.
The anionic polyacrylamide can be used for the flocculation and the sedimentation, the sedimentation and the clarification treatment of various industrial waste water, such as the iron and steel plant waste water, the electroplating waste water, the metallurgy waste water, the coal washing waste water and the sludge dewatering etc. The anionic polyacrylamide can also be used for the clarification treatment and the purification treatment of the drinking water. It is more widely used in the production and the processing, along with the coal industry, the metallurgy industry, the chemical industry, the paper making industry, the laundry and the textile industry etc.
Under special cases, the components in the sewage requires the anion or the cation to treat, however the PH value range is not suitable, so, it is necessary to adjust the PH value to the suitable range by using the acid based reagents, afterwards, using the polyacrylamide to achieve the best effect.
The attentions in the usage of the polyacrylamide:
Before the practical use, it is necessary to determine the optimal dosage of the polyacrylamide through the experiments, if the dosage is too low, there is no effect, if the dosage is excessive, the effect will be counterproductive, that is because when the concentration is over a certain degree, the polyacrylamide will not play the flocculation effect, but play the dispersion stabilization effect.
The prevention of the polyacrylamide degradation and the degradation time of the polyacrylamide
The cationic polyacrylamide aqueous solution has high viscosity, it can automatically degrade into the acrylamide solution after a certain time, the general degradation time is two to three days. When the cationic polyacrylamide is completely degraded, the cationic polyacrylamide solution will be like the normal water, no sticky, and will not react with the substance, which is the failure of the cationic polyacrylamide.
There are several methods which can destroy the viscous of cationic polyacrylamide solution, and accelerate the degradation speed of the cationic polyacrylamide solution.
The physical degradation:
By mechanical shearing under high strength, break the molecular chain of the cationic polyacrylamide, which greatly reduce the molecular weight of the solution, thereby, reduce the viscosity of the cationic polyacrylamide solution.
The chemical degradation:
Using the strong oxidation agent, or using the strong alkali, but this method must be considered with the consideration of the industrial production conditions in practical.
The acid and alkali heat will affect the cationic polyacrylamide properties, which will cause the hydrolyzed polyacrylamide polymer amio or the other functional groups that will influence the structure and the electrical impact of the cationic polyacrylamide.
The degradation of the cationic polyacrylamide solution is also affected by the temperature, the higher temperature will also accelerate the degradation of the cationic polyacrylamide.
How to extend the failure time of the polyacylamide?
in the dilution, the polyacrylamide is not required to be stirred with the metal, the diluted solution should be made for instant use, which means to use the diluted solution timely without long time storage. The environmental temperature is also very important, the preservation time should not be more than seven days.
Sometime, the adding of the formaldehyde antise can help to extend the preservation time of the diluted polyacrylamide solution.
The polyacrylamide solution is always made for the instant use within the day it is made, the use in the day afterwards will impact the practical effect of the polyacrylamide solution more or less, and will also cause the waste. So, in the practical operation, the polyacrylamide can be dissolved in the morning and be used at the night, that can avoid the waste and save time in the dissolving the polyacrylamide.