Application of Polydadmac AQ 224-P and AQ 225-P

1. Introduction to AQ 224-P and AQ 225-P

Polydadmac AQ 224-P and AQ 225-P are cationic polydiallyldimethylammonium chloride (PolyDADMAC) polymers widely used in water and wastewater treatment. These polymers are high-charge-density cationic coagulants, designed to destabilize negatively charged colloidal particles, natural organic matter (NOM), algae, fine suspended solids, and emulsified contaminants.

PolyDADMAC functions mainly via charge neutralization, rapidly destabilizing colloids and fine particles that are otherwise resistant to sedimentation. AQ 224-P and AQ 225-P are supplied as liquid concentrates, allowing easy dosing and integration into existing treatment processes. The two grades differ slightly in charge density and molecular weight, giving operators the flexibility to choose the optimal polymer for specific water qualities and treatment goals.

2. Municipal Drinking Water Treatment

2.1 Raw Water Clarification
AQ 224-P and AQ 225-P are commonly applied as primary coagulants for clarification of surface water, river water, and reservoirs. Natural waters often contain clay, silt, algae, and NOM, which carry negative charges that inhibit aggregation.

• When AQ 224-P or AQ 225-P is added, rapid charge neutralization occurs, producing microflocs that settle efficiently.

• Sedimentation is enhanced, turbidity is reduced, and filter performance downstream improves.

2.2 Coagulant Aid

• These polymers are often used in combination with alum, ferric chloride, or polyaluminum chloride.

• They enhance floc formation, reduce metal salt dosage, and minimize sludge volume.

• Flocs formed with these polymers are denser and settle more rapidly, improving clarifier efficiency.

2.3 Color and Organic Matter Reduction

• AQ 224-P and AQ 225-P remove humic and fulvic acids, which contribute to color and act as precursors to disinfection byproducts (DBPs).

• Their use reduces formation of trihalomethanes (THMs) and haloacetic acids (HAAs) during chlorination, supporting compliance with drinking water regulations.

2.4 Algae and Seasonal Turbidity Control

• Particularly effective during algal blooms or seasonal turbidity spikes.

• Neutralizes fine algae cells and colloidal particles, reducing filter headloss and maintaining plant stability.

3. Municipal Wastewater Treatment

3.1 Primary Clarification Enhancement

• AQ 224-P and AQ 225-P improve primary clarifier performance by promoting aggregation and faster settling of suspended solids, fats, oils, and grease (FOG).

• The polymers neutralize colloidal charges, forming dense, well-settling flocs, which enhances sedimentation.

3.2 Sludge Conditioning and Dewatering

• Applied upstream of gravity thickeners, centrifuges, and belt filter presses.

• Neutralizes sludge particle charges, promoting aggregation and improving free water release.

• Can be combined with high-molecular-weight polyacrylamide flocculants to optimize cake dryness and reduce overall polymer consumption.

3.3 Secondary Clarification Support

• Enhances removal of fine suspended solids that escape primary treatment.

• Reduces the load on biological treatment units and improves overall plant efficiency.

4. Industrial Wastewater Applications

4.1 Food and Beverage Industry

• Clarifies wastewater containing proteins, fats, oils, and suspended solids.

• Destabilizes emulsified oils and organic matter, facilitating separation and reducing chemical oxygen demand (COD) before biological treatment.

4.2 Pulp and Paper Industry

• Removes fiber fines, fillers, inks, and dissolved organics from process effluents.

• Enhances dissolved air flotation (DAF) performance and reduces residual turbidity.

4.3 Textile and Dyeing Industry

• Neutralizes negatively charged dyes and surfactants, improving color and solids removal.

• Promotes sedimentation of colloidal solids, facilitating downstream treatment.

4.4 Oil, Gas, and Petrochemical Effluent

• Effective at destabilizing emulsified oils and fine solids.

• Supports the performance of API separators, flotation units, and secondary clarifiers.

5. Operational Advantages

• Rapid coagulation due to high cationic charge density.

• Versatility: effective across a broad pH range and variable water qualities.

• Reduced sludge volume compared to inorganic coagulants alone.

• Improved downstream operations: enhances filtration, dewatering, and sludge handling.

• Ease of dosing as a stable liquid concentrate compatible with standard injection systems.

• Environmental compliance: reduces metal coagulant usage and associated residuals.

6. Typical Dosing and Integration

• Typical dosage: 0.5–10 mg/L, depending on raw water or wastewater quality.

• Can be applied directly or as a coagulant aid with inorganic salts.

• Injection points: rapid-mix basins, inline injection, or pre-clarifier feed.

• Often paired with anionic or nonionic flocculants for enhanced floc formation and improved sludge dewatering.

Grade Selection Guidelines:

• AQ 224-P – Medium-charge polymer for moderate turbidity or routine municipal water clarification.

• AQ 225-P – Slightly higher charge density, suitable for higher turbidity, color, or seasonal algal conditions.

7. Summary

Polydadmac AQ 224-P and AQ 225-P are high-performance cationic polymers used across municipal and industrial water and wastewater treatment applications. They rapidly destabilize colloidal particles and organic matter, improving sedimentation, filtration, and sludge dewatering. By selecting the appropriate grade, operators can optimize treatment processes, reduce chemical consumption, lower sludge volume, and enhance water quality compliance. These polymers are highly versatile, providing reliable performance across varying water qualities and industrial effluents.