Application of PolyDADMAC FLOQUAT FL 25 and FLOQUAT FL 40

PolyDADMAC (polydiallyldimethylammonium chloride) is a high-charge-density cationic polymer widely used as a primary coagulant or coagulant aid in water and wastewater treatment. Among the most recognized PolyDADMAC products globally are FLOQUAT FL 25 and FLOQUAT FL 40, manufactured by SNF Group. These two grades differ mainly in active content, charge concentration, and viscosity, allowing users to select the most suitable product depending on water quality, process design, and dosing strategy.

1. Overview of FLOQUAT FL 25 and FLOQUAT FL 40

FLOQUAT FL 25 is a lower active-content PolyDADMAC solution, typically around 25% solids, with moderate viscosity and excellent handling characteristics. It is especially favored in applications requiring precise dosing, rapid dispersion, and easy dilution.

FLOQUAT FL 40, by contrast, is a higher concentration PolyDADMAC, generally around 40% solids, offering higher charge density per unit volume. This allows reduced transportation costs, lower storage volume, and improved efficiency in high-demand coagulation systems.

Both products share the same fundamental mechanism of action: charge neutralization. Their strongly cationic nature neutralizes negatively charged colloids, fine suspended solids, organic matter, and emulsified oils, thereby destabilizing particles and enabling rapid aggregation.

2. Municipal Drinking Water Treatment

One of the most important applications of FLOQUAT FL 25 and FLOQUAT FL 40 is in municipal drinking water treatment plants. Raw surface water typically contains negatively charged suspended solids, such as clay, silt, algae, bacteria, and natural organic matter. FLOQUAT FL 25 and FLOQUAT FL 40 are dosed at the rapid-mix stage to neutralize these charges.

• FLOQUAT FL 25 is commonly selected for small to medium-sized water treatment facilities, where precise dosage control and easy pumping are critical.

• FLOQUAT FL 40 is preferred in large municipal plants, where high throughput requires stronger charge neutralization and reduced chemical consumption.

In many systems, these PolyDADMAC products partially or completely replace inorganic coagulants such as alum or ferric salts, resulting in lower sludge production, wider pH operating range, and reduced residual metals in treated water.

3. Wastewater Clarification and Primary Treatment

In municipal and industrial wastewater treatment, FLOQUAT FL 25 and FLOQUAT FL 40 are widely applied as primary coagulants or coagulant aids. Wastewater streams typically contain high levels of suspended solids, colloidal organics, emulsified fats, oils, and greases (FOG), all of which are effectively destabilized by PolyDADMAC.

FLOQUAT FL 25 is frequently used where wastewater composition fluctuates significantly, as its lower viscosity allows rapid dosage adjustments and improved mixing. FLOQUAT FL 40, with its higher active content, is advantageous in high-load wastewater systems, enabling reduced chemical feed rates while maintaining excellent clarification efficiency.

4. Sludge Conditioning and Dewatering

Another critical application of FLOQUAT FL 25 and FLOQUAT FL 40 is in sludge conditioning prior to dewatering. While PolyDADMAC is not typically the sole flocculant for dewatering, it serves as an excellent pretreatment coagulant, improving the performance of downstream cationic polyacrylamide (CPAM) flocculants.

By neutralizing the surface charge of sludge particles, FLOQUAT FL 25 and FLOQUAT FL 40 enhance floc structure, reduce polymer demand, and improve cake solids. FLOQUAT FL 40 is especially effective in high-solids sludge due to its concentrated charge density, while FLOQUAT FL 25 is commonly used in belt presses and centrifuges requiring uniform polymer distribution.

5. Industrial Process Water and Effluent Treatment

FLOQUAT FL 25 and FLOQUAT FL 40 are extensively used in industrial wastewater treatment across sectors such as oil & gas, petrochemicals, textiles, pulp and paper, food and beverage, and metal processing. These industries generate complex effluents with fine particulates, dyes, surfactants, and emulsified oils.

PolyDADMAC FLOQUAT grades effectively break emulsions, remove color, and reduce COD and turbidity. FLOQUAT FL 40 is often selected where space constraints or high contaminant loading demand a more concentrated coagulant, whereas FLOQUAT FL 25 is ideal for continuous-flow systems requiring stable, controlled dosing.

6. Papermaking and Pulp Processing

In the pulp and paper industry, FLOQUAT FL 25 and FLOQUAT FL 40 are applied as fixing agents and retention aids. They neutralize anionic trash, improve fines and filler retention, and enhance drainage on the paper machine. FLOQUAT FL 25 is frequently used in wet-end chemistry programs, while FLOQUAT FL 40 is selected for high-speed machines and high-recycled-fiber systems.

7. Compatibility and Operational Advantages

Both FLOQUAT FL 25 and FLOQUAT FL 40 are fully compatible with inorganic coagulants, polyamines, and polyacrylamide flocculants. Their liquid form allows easy handling, accurate dosing, and rapid solubility. They function effectively across a wide pH and temperature range, making them reliable under variable operating conditions.