In the field application of polyacrylamide, the common problems include poor flocculation effect, mud pressure, muddy water and “water poisoning” and so on. In view of these problems, the following is a detailed analysis and solutions

Flocculation effect is not good

Type selection:

• • Improper PAM selection, such as cationic PAM for the treatment of anionic sewage, or molecular weight mismatched PAM for specific sewage.
  • Solution: According to the nature of sewage (such as PH value, suspended matter type, organic matter content, etc.), the PAM model is rationally selected, and the best model is determined by small test.

Dosage:

• • Problem: Too much or too little PAM will affect the flocculation effect.
  • Solution: Determine the best dosage through the test, and adjust according to the actual situation to avoid excessive or insufficient.

Equipment matching:

• • Problem: The water pump, pharmaceutical dosing equipment, sewage water amount, etc., do not match, resulting in uneven PAM distribution or uneven dosing.
  • Solution: Ensure that all the equipment matches each other, check the operating status of the equipment regularly, and keep the equipment clean and normal operation.

Median length, runway distance and baffle

• • Problem: the length of the cylinder is too short or too long, the distance to run is not appropriate, the baffle is set improperly, etc., may affect the mixing effect of PAM and sewage.
  • Solution: According to the equipment design principle and sewage characteristics, reasonable setting of cylinder length, run to distance and baffle to optimize the mixing effect.

 Press the mud to dry

Inlet pressure and sludge pump pressure

• • Problem: Insufficient inlet pressure or unstable sludge pump pressure, resulting in poor sludge dewatering effect.
  • Solution: Check and adjust the inlet pressure and sludge pump pressure to ensure they are stable and adequate.

Backwash and cloth cleaning

• • Problem: Backwashing is not timely or the filter cloth is not clean, resulting in clogging of the filter cloth.
  • Solution: Regular backwash and filter cloth cleaning to keep the filter cloth smooth.

High clay treatment

• • Problem: The high clay content causes the sludge to be viscous and difficult to dehydrate.
  • Solution: Add other agents (such as coagulants, coagulants, etc.) to destroy the viscosity of the sludge and improve the dehydration effect.

Turn over the pot to create muddy water

Sewage inlet and sludge outlet match

• • Problem: The sewage inlet flow is too large or the mud outlet design is unreasonable, resulting in muddy water over the tank.
  • Solution: According to the sewage treatment capacity, the sewage inlet and the mud outlet are reasonably designed to ensure that the two match.

Sedimentation tank capacity and dose match

• • Problem: The precipitation tank capacity is insufficient or the drug dose is too large, resulting in sewage in the tank is not sufficiently precipitated and discharged.
  • Solution: Adjust the sedimentation tank capacity and dosage according to the actual demand to ensure that the sewage has enough residence time and reaction time in the tank.

 “Water poisoning” phenomenon and solutions

Due to the instability of raw materials or pharmaceutical mismatch, water quality deteriorates, PAM loses flocculation, and the circulating water system is paralyzed. The concrete performance is that the sewage does not flocculate, the sewage from the sand washing machine is in the state of small rice grains, and the poly aluminum can be flocculated at the mud press end. This situation is most obvious in the sand washing plant, because of the instability of the raw materials, even if the stone in a mine is also divided into layers, the agent does not match, which will cause the site workers to feel that the amount of medicine is small and there is no flocculation, and the water quality changes after adding too much medicine, the circulating water system is paralyzed, and how to add medicine has no effect. The viscosity of the sludge is too large, which will stick to the wall in the sedimentation tank and cause tank blockage. And sewage treatment is not clean, washing sand is not clean.

Solution

• • Neutralizing water quality: Add cationic PAM neutralization: Add cationic PAM according to the water quality to neutralize the negatively charged substances in the water quality.
  • Adding polyaluminum neutralization: The use of polyaluminum chloride (PAC) and other coagulants for neutralization treatment to improve the flocculation performance of sewage.
  • Field condition adjustment: If conditions permit, appropriate amount of soil or adsorbent can be added to the sand washing machine to adsorb harmful substances and suspended substances in the water.
  • Comprehensive treatment: Strengthen water quality monitoring and pharmaceutical management to ensure that the type and dosage of pharmaceutical agents match the nature of sewage. Check and maintain equipment regularly to ensure proper operation and cleanliness. Improve employees’ environmental awareness and operational skills, strengthen training and guidance.