Selection of flocculant for municipal sewage

- Aug 24, 2019-

According to the customer's requirements, we can choose a matching flocculant with different field technology and equipment.
Choose suitable and best solutions for different industries and regions.
How to choose flocculant for dehydration in sewage treatment plant?
In the treatment process of municipal sewage treatment plant, sludge dewatering treatment is required, that is, solid suspended substance in sewage is separated from water by pressure filter, and flocculant PAM is needed in the process of dewatering.
Since there are many types and types of flocculant, how to choose flocculant for urban sewage plant?
What factors should be considered?
1. Source, property, composition and solid phase content of sludge.
Cationic flocculant is generally used to treat organic sludge, while anion flocculant is used to treat inorganic sludge.
Cationic flocculant should not be used when it is very alkaline, and anion flocculant should not be used when it is very acidic.
Sludge with high solid content usually has large amount of flocculant.
Therefore, cationic flocculant needs to be used in urban sewage plant, and the specific dosage needs to pass through the site
Experiment to determine.
2. Size of flocs: too small flocs will affect the drainage speed, and too large flocs will bind more water and reduce the degree of mud and biscuits.
The size of flocs can be adjusted by selecting molecular weight of flocculant.
Why do we think about floc size?
Isn't the bigger the better?
Isn't.
Different filter presses are used in the field process, so it is necessary to judge according to the condition of the filter press.
3. Mixing of flocculant and sludge: the flocculant must fully react with the sludge at a certain location of the dehydration equipment to produce flocculation.
For this reason, the viscosity of flocculant solution must be suitable and can be evenly mixed with sludge under existing equipment conditions.
Whether they mix well or not is another key factor in success.
The viscosity of flocculant solution is related to its molecular weight and configuration concentration.
There are still many aspects to be considered in the selection of flocculant in urban sewage plant.
In a word, the selection of dehydrating flocculant is very important in urban sewage plant.
How to do the selection test of flocculant for sewage treatment?
When flocculant is used in sewage treatment, a small trial, namely beaker test, is needed to select the use plan of QUANSEN flocculant with better flocculation effect and sewage treatment agent.
So sewage treatment station sewage treatment flocculant selection test how to do?
Shanghai puyi comprehensively introduces the steps of flocculant selection test and matters needing attention, hoping to be helpful for on-site sewage treatment personnel.
Purpose of selection test of flocculant.
The flocculant used before the sewage treatment site is used as a reference to select the flocculant with better mud compaction effect and reduce the drug cost of paper mill as far as possible.
Preparation for flocculation selection test.
1. Concentrated pool water samples: several.
2. Water samples after dosing: several.
3. 0, 1% flocculant solution: weigh 0.2g flocculant in 250ml beaker, add 200ml water, and dissolve.
4. 500ml beaker, glass rod and pipette.
3. Flocculant selection test process (water sample flocculation test selection).
1. Use measuring cylinder to accurately measure 500ml water sample after dosing into 4 500ml beakers.
Number them in order.
2. Use a pipette to remove 1ml, 2ml, 3ml and 4ml of the existing 0.1% flocculant solution and add them to the beaker in sequence (the converted amount of 0.1% flocculant solution is 2 mg/L, 4mg/L, 6mg/L and 8 mg/L respectively);
Stir for 15S and let stand for 30min.
3. After 30min, the optimal dosage of the currently used flocculant was 4ml (the dosage of 8 mg/L was converted into the dosage of 0.1% flocculant solution).
4. Transfer 8ml of 0.1% flocculant solution with different Numbers to beaker in sequence;
Stir for 15S and let stand for 30min.
5. Record the number of flocculant with clear supernatant solution, little floating dust and large flocculation.
6. Break up the flocculation group to see the effect of flocculation again.
7. Use pipette to remove 1ml, 2ml, 3ml and 4ml of 0.1% flocculant solution with good effect and add them to beaker in sequence (the amount of adding 0.1% flocculant solution is 2 mg/L, 4mg/L, 6mg/L and 8mg/L respectively);
Stir for 15S and let stand for 30min.
8. Record the number of flocculant with clear supernatant solution, little floating dust and large flocculation.
9. Break up the flocculation group to see the effect of flocculation again.
Iv. Conclusion on selection of flocculant.
In the water sample test, the treatment effect of the original flocculant was satisfactory when the dosage was 8mg/L, while the treatment effect of QUANSEN flocculant was basically the same as that of the present flocculant when the dosage was 4 mg/L.
That is, under the same effect, the amount of flocculant added by our company is only half that of the original flocculant added.
This proves that all sewage treatment stations using urban flocculant need to pass the test and choose the correct flocculant dosage form.