In-Depth Applications in Water Treatment
Industrial Wastewater Treatment
Wastewater characteristics vary across industries, making the selection of the appropriate PAM type critical:
Anionic PAM: Suitable for wastewater with coarse suspended particles, neutral to alkaline pH, and positively charged particles, such as steel plant wastewater, electroplating wastewater, coal washing wastewater, and metallurgical wastewater, with remarkable treatment results.
Cationic PAM: Suitable for negatively charged organic wastewater, such as from alcohol plants, breweries, monosodium glutamate plants, sugar mills, meat processing plants, and textile dyeing mills. Its treatment efficiency can be several to dozens of times higher than anionic or nonionic PAM.
Nonionic PAM: Suitable for acidic wastewater environments, making it an ideal choice for acid pickling wastewater treatment.
Water Purification and Drinking Water Treatment
For water treatment plants sourcing from rivers, PAM can be used in combination with inorganic flocculants (such as polyaluminum chloride). The dosage is only 1/50 of that of inorganic flocculants, yet the effectiveness is several times higher, particularly suitable for treating river water with significant organic pollution.
Refined Applications in the Papermaking Industry
PAM has three main applications in the papermaking industry: strength agent, retention and drainage aid, and fiber dispersant.
1. Paper Strength Agent
Cationic PAM can directly bind with pulp fibers, significantly improving paper dry and wet strength. As white water closed-loop circulation increases in papermaking, amphoteric PAM, containing both cationic and anionic groups, performs better than single-ion products in high-salinity environments.
2. Retention and Drainage Aid
Through bridging flocculation, PAM aggregates fine fibers and fillers (such as calcium carbonate and talc) and retains them in the paper sheet, while accelerating drainage, improving machine speed, and increasing production.
3. Fiber Dispersant
In the production of thin paper products such as high-grade tissue paper and napkins, high-molecular-weight (approximately 20 million) anionic PAM serves as a dispersant, effectively preventing long-fiber flocculation and improving paper uniformity and softness.
Usage Precautions and Dissolution Guidelines
The effectiveness of PAM is closely related to its dissolution state. The following are key operational points:
Dissolution Time: A minimum of 40 minutes is recommended to ensure complete dissolution.
Agitation Speed: The linear agitation speed should be controlled at approximately 1 meter/second. Excessive speed can shear and break molecular chains, reducing viscosity, while insufficient speed results in incomplete dissolution.
Storage Time: PAM solutions should ideally be used within 12 hours after dissolution and should not be stored beyond 48 hours to prevent degradation and loss of effectiveness.
