At NINGBO INNO PHARMCHEM CO.,LTD., we believe in empowering our clients with a deep understanding of the products they use. Polyacrylamide (PAM), particularly its anionic form (APAM), is a cornerstone in modern water treatment. This article aims to demystify how PAM works, explaining the scientific mechanisms that make it such an effective flocculant.

Water, in its natural state or after industrial use, often contains suspended impurities. These impurities, such as fine clay particles, organic matter, and microscopic organisms, are typically very small and possess surface charges. These charges cause them to repel each other, maintaining a stable suspension and making them difficult to remove through simple sedimentation. This is where PAM's action begins.

PAM is a long-chain, water-soluble polymer. Its effectiveness in water treatment stems from its molecular structure, which contains numerous amide groups. When APAM is introduced into water, these functional groups play a crucial role. The anionic nature of APAM means it carries a negative charge. This charge helps in two primary ways:

1. Charge Neutralization: The negatively charged APAM molecules can neutralize the positive charges that might be present on some suspended particles or, more importantly, it can interact with the electrical double layer surrounding negatively charged particles. This charge reduction destabilizes the particles, reducing their mutual repulsion.

2. Bridging Flocculation: This is perhaps the most significant mechanism. APAM polymers are large molecules with many active sites. Once destabilized, suspended particles can come into contact with different parts of the long polymer chains. The polymer acts as a bridge, physically linking numerous individual particles together. This process forms larger, heavier aggregates known as flocs. These flocs are substantially easier to remove from the water through sedimentation, flotation, or filtration processes.

The effectiveness of PAM is influenced by several factors, including its molecular weight, charge density (for ionic PAM), and the characteristics of the water being treated (pH, temperature, ionic strength). Higher molecular weight generally leads to better bridging capabilities, while the correct charge helps in initial destabilization. For example, in mining wastewater treatment, where a high concentration of negatively charged mineral fines is common, APAM is particularly effective due to its bridging action. Similarly, in paper manufacturing, its ability to bind fine fibers and fillers improves retention and drainage.

The process of using PAM typically involves dissolving it in water to create a dilute solution before adding it to the wastewater. This preparation step is crucial to ensure the polymer chains are fully extended and can maximize their bridging capacity. NINGBO INNO PHARMCHEM CO.,LTD. provides guidance on the optimal preparation and dosage for various applications, ensuring that clients can harness the full potential of this advanced polymer.

In essence, Polyacrylamide works by providing both electrostatic and physical bridging mechanisms that overcome the stability of suspended particles in water, transforming them into manageable flocs. This scientific principle underpins its widespread use in ensuring cleaner water across numerous industries.