Highly cross-linked cationic polyacrylamide emulsion (640HIB) is an advanced water-soluble polymer designed primarily for use in sludge dewatering, industrial wastewater treatment, and clarification applications. The “cross-linked” nature of this polymer structure gives it enhanced bridging ability, high floc strength, and greater shear resistance compared to conventional linear or lightly branched polymers.

640HIB is supplied as an oil-in-water emulsion, offering quick inversion and solubility in aqueous systems. This type of flocculant is characterized by its high molecular weight, high cationic charge density, and dense, three-dimensional structure. These characteristics make 640HIB especially well-suited to treat difficult sludges and demanding solid-liquid separation processes.

1. Primary Application: Municipal Sludge Dewatering

The leading application of 640HIB is in mechanical dewatering of municipal sludge, including waste activated sludge (WAS) and mixed primary and secondary sludges. These sludges typically have a high water content and low dewaterability due to fine particle size and the presence of biological material.

640HIB is used with mechanical dewatering equipment such as:

• Centrifuges

• Belt filter presses

• Screw presses

• Plate-and-frame filter presses

Its cross-linked polymer structure allows it to:

• Form large, dense, and stable flocs

• Withstand shear during processing

• Release water efficiently from the floc matrix

Benefits:

• Higher cake solids: Reduces disposal volume and cost

• Improved filtrate clarity: Less suspended solids in separated water

• Low polymer dosage: Due to efficient flocculation and strong bridging

• Fast floc formation: Ideal for continuous high-speed systems

2. Industrial Sludge Conditioning and Dewatering

640HIB is highly effective for dewatering organic-rich, fibrous, or oily industrial sludges, such as those from:

• Food and beverage production

• Textile and dyeing industries

• Pulp and paper mills

• Refineries and petrochemical plants

• Meat and dairy processing facilities

These types of sludge are usually more challenging due to emulsified oils, grease, and fine solids. Traditional flocculants may struggle to form durable flocs in such environments. However, 640HIB:

• Penetrates and binds oily/fibrous particles effectively

• Forms flocs resistant to shear and emulsification

• Improves dewatering results even with low solids content

3. Performance in High-Shear Systems

640HIB is particularly suited for high-shear applications such as centrifuge dewatering, where floc breakage is a major challenge. In traditional systems, fragile flocs often break apart under centrifugation, reducing dewatering efficiency. The cross-linked architecture of 640HIB enables:

• Formation of shear-resistant flocs

• Stable floc structure during rapid rotational motion

• Enhanced solid-liquid separation with minimal re-suspension

4. Belt and Screw Press Dewatering

In belt press and screw press systems, rapid and efficient floc formation is critical. 640HIB’s highly cross-linked structure provides superior performance:

• Enables rapid water release from flocs

• Forms compressible sludge cake with high solids content

• Reduces belt blinding and improves filtration efficiency

This allows facilities to increase throughput and reduce polymer consumption without compromising on performance.

5. Treatment of Greasy or Oil-Laden Sludges

Oil-contaminated sludges, such as those from refineries, chemical plants, and grease traps, are difficult to treat due to their hydrophobic nature. 640HIB offers an excellent solution by:

• Interacting with oily particles through its cationic charge

• Disrupting stable emulsions

• Promoting effective aggregation and water release

This makes 640HIB ideal for demulsification and dewatering in challenging oily sludge environments.

6. Wastewater Clarification and Solids Settling

In addition to dewatering, 640HIB is used for clarification of wastewater in:

• Primary clarifiers

• Lamella separators

• Dissolved air flotation (DAF) units

• Gravity settlers

Its fast-acting and durable flocculation capabilities allow:

• Removal of suspended solids (TSS)

• Reduction in turbidity

• Enhanced sedimentation or flotation performance

• Lower sludge volume

This is particularly beneficial in industrial wastewater plants where rapid separation is needed within limited retention times.

7. Compatibility with Various Wastewater Conditions

640HIB maintains effectiveness in variable water chemistries and operational settings:

• Works in cold water without sacrificing floc formation

• Performs well in saline or high-conductivity waters

• Effective across a wide pH range (typically 4–9)

• Suitable for both batch and continuous systems

8. Environmental and Cost Advantages

By using 640HIB, treatment plants can achieve operational efficiency and cost savings:

• Reduced sludge disposal costs due to higher dryness of dewatered cake

• Lower energy use during drying or incineration of sludge

• Improved effluent quality, aiding in regulatory compliance

• Minimized need for additional chemicals, such as coagulants or demulsifiers

9. Applications Summary

10. Technical Features at a Glance

• Type: Water-in-oil cationic polyacrylamide emulsion

• Structure: Highly cross-linked (three-dimensional matrix)

• Charge: High cationic charge density

• Molecular weight: Very high

• Solubility: Quick inversion in water with low-energy mixing

• Compatibility: Works with various dosing equipment and water chemistries

Conclusion

Highly cross-linked cationic polyacrylamide emulsion (640HIB) is a next-generation flocculant that delivers exceptional performance in challenging sludge and wastewater treatment environments. With its enhanced shear resistance, superior floc strength, and efficient solid-liquid separation capabilities, it stands out as the flocculant of choice for municipal and industrial facilities seeking reliable, high-throughput dewatering solutions. Whether deployed in high-speed centrifuges or in greasy, oily sludge systems, 640HIB consistently reduces operational costs and enhances treatment efficiency, making it an indispensable tool for modern wastewater management.