Main Application of Anionic Polyacrylamide (FLOPAM DW 533)

Anionic polyacrylamide, especially FLOPAM DW 533, plays a significant role across various industrial processes due to its superior flocculation and settling performance. As a high molecular weight, high charge density anionic polyacrylamide emulsion, FLOPAM DW 533 is engineered for solid-liquid separation tasks, particularly in environments with negatively charged colloidal particles. This polymer is widely used in water and wastewater treatment, mining, mineral processing, paper manufacturing, and sludge dewatering. Below is an in-depth overview of the main application of FLOPAM DW 533, with special focus on its use in sludge dewatering—its primary industrial deployment.

1. Sludge Dewatering – The Core Application

FLOPAM DW 533 is specifically developed for mechanical sludge dewatering applications. Its name, DW, stands for "Dewatering," reflecting its optimized design for sludge conditioning before mechanical dewatering by equipment such as belt filter presses, centrifuges, screw presses, or chamber filter presses. In wastewater treatment plants, one of the most critical steps is to reduce the water content in sludge, which in turn reduces sludge volume, transport cost, and disposal cost.

1.1 Mechanism of Action

When FLOPAM DW 533 is added to sludge, its long polymer chains and anionic charge help:

• Neutralize surface charges on negatively charged sludge particles (colloids),

• Bridge fine particles into larger flocs,

• Promote rapid water release under shear (from pressing or centrifugation),

• Stabilize floc structure under pressure or high-speed rotation.

The flocs formed are firm, non-dispersive, and exhibit enhanced drainage properties, improving the throughput and performance of dewatering systems.

1.2 Target Sludges

FLOPAM DW 533 is used for:

• Activated sludge (biological sludge),

• Primary sludge (raw settled solids),

• Dissolved air flotation (DAF) sludge,

• Thickened and digested sludges from municipal or industrial wastewater.

It is particularly effective for high-volume sludge with moderate organic content, such as those found in municipal WWTPs or food industry effluents.

1.3 Equipment Compatibility

FLOPAM DW 533 is fully compatible with most types of dewatering equipment:

• Centrifuges: Improves solids capture and clarity of centrate.

• Belt filter presses: Enhances cake dryness and belt throughput.

• Screw presses: Stabilizes flocculation under pressure and slow shear.

• Filter presses: Provides stronger floc for rapid cycle time and dry cake formation.

2. Wastewater Treatment (Clarification and Settling)

Beyond sludge handling, FLOPAM DW 533 is used in secondary clarification and settling basins to promote rapid sedimentation of suspended solids. In both municipal and industrial wastewater, fine particles often remain suspended due to their small size and surface charge. FLOPAM DW 533 helps:

• Aggregate suspended solids,

• Accelerate settling in clarifiers,

• Reduce turbidity in treated water,

• Enhance thickener underflow concentration.

It is especially effective in:

• Municipal sewage treatment,

• Industrial process water clarification (e.g., in the textile, food, petrochemical industries),

• Stormwater and sediment basin treatment.

3. Mining and Mineral Processing

In the mining sector, FLOPAM DW 533 finds application in tailings dewatering and thickening, especially for coal, gold, iron ore, and copper mining. Tailings from flotation, grinding, or leaching often contain ultra-fine particles that are hard to settle. FLOPAM DW 533 acts as a:

• High-efficiency tailings flocculant,

• Thickener aid to increase underflow solids content,

• Centrifuge additive to improve water recovery and cake dryness.

In flotation tailings of sulfide minerals like pyrite or chalcopyrite, FLOPAM DW 533 bridges and settles the particles, accelerating the recovery of process water and improving tailings handling.

4. Paper Industry Applications

In papermaking, particularly in the whitewater circuit, FLOPAM DW 533 is used as:

• A retention and drainage aid,

• A clarification flocculant in paper machine water loops,

• An aid in sludge thickening and dewatering of pulp and fiber sludge.

Its high anionicity helps neutralize cationic trash and reduce stickies in recycled fiber processing. It improves paper quality by enhancing filler retention and improving drainage from the wet end of the machine.

5. Compatibility and Operational Considerations

5.1 Dosage

• Typical dosage: 1–10 g per kg of dry solids, depending on sludge type.

• Must be diluted to 0.1–0.5% concentration before feeding.

• Overdosing can lead to re-dispersion and poor water release.

5.2 Handling

• Supplied as a dewatered emulsion, generally at 35–40% active content.

• Requires emulsion inversion unit to prepare working solution.

• Storage in IBCs (1,050 kg) or bulk tanks.

5.3 Water Chemistry

• Works best at neutral to alkaline pH (6.5–9).

• Sensitive to high levels of multivalent cations (Fe³⁺, Al³⁺) in some cases.

• Compatible with ferric/alum coagulants in pre-treatment.

Conclusion

The main application of anionic polyacrylamide FLOPAM DW 533 is sludge dewatering, where it provides excellent flocculation performance, water release, and cake dryness in mechanical dewatering systems such as centrifuges and belt filter presses. Its secondary applications include wastewater clarification, mining tailings thickening, and paper industry retention. The product's high molecular weight and anionic charge make it particularly effective in separating fine solids from water in various industrial processes. Its proper use improves treatment efficiency, reduces sludge handling costs, and enhances water reuse and environmental compliance.