Cationic polyacrylamide ZETAG® 8139 DL is a premium-grade, high-molecular-weight cationic flocculant produced by BASF under the ZETAG brand. It is supplied in dry granular powder form and features a medium-to-high cationic charge density, making it highly effective for sludge dewatering, solid–liquid separation, and wastewater clarification. Its main application is in municipal and industrial wastewater treatment, where it plays a critical role in improving treatment efficiency, reducing sludge volume, and lowering operational costs.

1. Primary Application: Sludge Dewatering in Wastewater Treatment

The most important and largest application of ZETAG 8139 DL is sludge dewatering, especially in municipal sewage treatment plants. During biological and physical wastewater treatment, large volumes of sludge are generated that must be dewatered before disposal or further processing. This sludge typically contains fine, negatively charged organic particles that are difficult to separate without chemical assistance.

1.1 Working Mechanism in Sludge Conditioning

ZETAG 8139 DL functions mainly through:

• Charge neutralization, which reduces the electrostatic repulsion between negatively charged sludge particles.

• Polymer bridging, where long molecular chains connect multiple particles into strong, large flocs.

• Compression of the electrical double layer, allowing tighter aggregation.

These mechanisms enable the formation of dense, shear-resistant flocs that release water more easily during mechanical dewatering.

1.2 Performance in Mechanical Dewatering Equipment

ZETAG 8139 DL is widely used in:

• Belt filter presses

• Decanter centrifuges

• Screw presses

• Plate-and-frame filter presses

After proper conditioning with ZETAG 8139 DL, sludge exhibits:

• Higher cake dryness

• Faster filtration rates

• Clearer filtrate

• Reduced polymer consumption

In typical municipal applications, ZETAG 8139 DL can improve sludge dry solids content by 20–35%, significantly reducing sludge transportation and disposal costs. It also minimizes polymer overdosing risks due to its wide operating window.

2. Industrial Wastewater Treatment Applications

Beyond municipal sewage, ZETAG 8139 DL is widely applied in industrial wastewater treatment, where wastewater characteristics are more complex and often contain high levels of suspended solids, oils, fibers, dyes, and heavy metals.

2.1 Papermaking and Pulp Processing

In the papermaking industry, ZETAG 8139 DL is used to treat:

• White water

• Primary sludge

• Secondary biological sludge

It effectively flocculates fibers, fillers, and organic solids, improving:

• Sludge dewaterability

• Filler recovery

• Clarifier efficiency

• Overall water recycling rate

It also reduces chemical oxygen demand (COD) in effluent and improves compliance with discharge standards.

2.2 Textile and Dyeing Effluent

Textile wastewater contains fine dye particles, surfactants, and organic colloids that are difficult to settle. ZETAG 8139 DL is used after coagulation to:

• Remove color

• Reduce turbidity

• Improve sedimentation speed

• Enhance flotation efficiency

Its strong charge neutralization ability makes it particularly effective for dye-bearing wastewater containing reactive and disperse dyes.

2.3 Food and Beverage Processing Wastewater

Food wastewater is rich in fats, proteins, starches, and suspended organic matter. ZETAG 8139 DL is used to condition:

• Slaughterhouse effluent

• Dairy wastewater

• Brewing and beverage wastewater

• Starch processing wastewater

It produces compact flocs that improve dissolved air flotation (DAF) performance and reduce organic load in final discharge.

3. Mining, Coal, and Mineral Processing

ZETAG 8139 DL also finds application in coal preparation plants and mineral processing operations. It is mainly used for:

• Coal slime dewatering

• Clarification of thickener overflow

• Conditioning of fine mineral sludges

Cationic flocculants like ZETAG 8139 DL are especially effective in coal washery sludge, where organic carbon-rich fine particles respond well to positive charge neutralization. Improved settling speed and higher underflow concentration lead to better water recovery and lower tailings pond volumes.

4. Oilfield and Petrochemical Wastewater

In oil production and refining, large volumes of oily wastewater are produced. ZETAG 8139 DL is applied to:

• Separate emulsified oil from water

• Flocculate polymer flooding residues

• Improve flotation efficiency in API separators and DAF units

It helps reduce oil content, suspended solids, and sludge volume, making it suitable for environmentally compliant discharge or reinjection.

5. Municipal Drinking Water Treatment and Clarification

Although anionic polymers dominate raw water clarification, ZETAG 8139 DL is sometimes used in specific surface water or river water systems with negatively charged colloids and low alkalinity. When combined with aluminum salts or ferric salts, it:

• Enhances floc strength

• Improves settling velocity

• Reduces residual turbidity

• Lowers coagulant dosage

6. Advantages of ZETAG 8139 DL in Practical Applications

ZETAG 8139 DL is widely selected because of the following technical advantages:

• High molecular weight with strong bridging capability

• Medium-to-high charge for excellent sludge conditioning

• Rapid floc formation and fast dewatering speed

• Low dosage requirement

• Broad pH and temperature adaptability

• Excellent compatibility with inorganic coagulants

• Stable performance under high shear conditions

These advantages make it suitable for both organic sludges and mixed industrial sludges.