Praestol 655 BC is a kind of cationic polyacrylamide with extremly high charge and medium  molecualr weight.mainly used for water treatment and Sludge dewatering .

Main Application of Cationic Polyacrylamide (Praestol 655 BC)

Praestol 655 BC is a strongly cationic, medium-molecular-weight polyacrylamide flocculant manufactured by Solenis (formerly BASF). It is designed for sludge treatment, solid–liquid separation, and wastewater clarification. Among all its uses, the primary and most important application is sludge dewatering and sludge conditioning in municipal and industrial wastewater systems.

1. Primary Application: Sludge Dewatering (Main Application)

The main application of Praestol 655 BC is sludge dewatering, especially for:

• Municipal sewage sludge (WAS & primary sludge)

• Biological sludge from activated-sludge systems

• Industrial biological sludge

• Mixed sludge with high organic content

Sludges from wastewater treatment plants typically carry a strong negative surface charge, making them hard to settle or dewater. Praestol 655 BC’s strong cationic charge neutralizes this charge quickly, forming large, durable flocs.

Benefits in sludge dewatering:

• Increases floc size and density

• Improves cake solids on centrifuge, belt press, and filter press

• Improves filtrate clarity

• Reduces polymer dosage compared with lower-charge polymers

• Accelerates drainage and reduces sludge handling costs

Praestol 655 BC is widely used as a primary flocculant for mechanical dewatering, making this its single most important application globally.

2. Wastewater Clarification (Secondary Application)

Praestol 655 BC is also used for clarifying municipal and industrial wastewater, especially where the effluent contains negatively charged colloids and organic particles.

Typical uses:

• Secondary clarifier enhancement

• Dissolved Air Flotation (DAF) sludge removal

• Thickening of biological sludge

• Removal of suspended solids (TSS)

• Pre-treatment of industrial wastewater

Industries where Praestol 655 BC is commonly used:

• Food processing

• Beverage and dairy

• Chemical plants

• Pharmaceuticals

• Textile wastewater with organic load

Its strong cationic charge ensures efficient bridging and floc formation for rapid settling.

3. Paper & Pulp Industry (Retention / Sludge Dewatering)

In paper mills, Praestol 655 BC is used primarily for:

• Dewatering paper mill biological sludge

• Treating fiber recovery sludge

• Flocculation in effluent treatment plants

It is not typically used as a retention aid on the paper machine (that function usually uses higher-molecular-weight cationic PAM), but it is very effective in sludge dewatering lines.

4. Industrial Sludge Containing Organic Matter

Praestol 655 BC performs extremely well on sludge types such as:

• Brewery and fermentation sludge

• Food-protein sludge

• Petrochemical biological sludge

• Dye-house biological sludge

Any sludge rich in organic, negatively charged solids is ideal for this grade.

Summary

In simple terms: