Skip to content 
When should you add PAC? When should you add PAM? How do these chemicals work together for optimal wastewater treatment?
In industrial wastewater treatment, polyaluminum chloride (PAC) and polyacrylamide (PAM) are the most commonly used coagulants and flocculants. However, many businesses are unsure about how to use them effectively. Improper dosing or incorrect order of addition can lead to poor treatment results, chemical wastage, or even secondary pollution.
This article will explain the working principles of PAC and PAM, their ideal dosage ratios, and the best applications for different types of PAM to help businesses optimize wastewater treatment, reduce costs, and improve efficiency.
How Do PAC and PAM Work in Wastewater Treatment?
Using PAC and PAM together enhances solid-liquid separation and significantly improves wastewater purification.
1、The Role of PAC: Coagulation and Suspended Solids Removal
🔹 PAC (Polyaluminum Chloride) is an inorganic polymer coagulant that works by hydrolyzing to form colloidal particles, which neutralize the negative charges of suspended solids, causing them to clump together into small flocs.
✔ How It Works:Hydrolysis reaction: Releases Al³⁺ ions that adsorb suspended particles in water.
Charge neutralization: Reduces repulsion between particles, helping them aggregate.
Formation of microflocs: These are small initial flocs that are not yet large enough to settle quickly.
🚀 Key Benefits of PAC:
✅ Effective in removing suspended solids, turbidity, color, and heavy metals.
✅ Suitable for industrial wastewater, drinking water treatment, electroplating wastewater, and textile dyeing wastewater.
✅ Works best when combined with PAM, which helps form larger, faster-settling flocs.
2、The Role of PAM: Enhancing Flocculation and Improving Sedimentation
🔹 PAM (Polyacrylamide) is a high-molecular-weight flocculant that binds small PAC-formed flocs together, making them larger and heavier so they settle quickly.
✔ How It Works:Hydrolysis forms long molecular chains, which can attach to multiple microflocs.
Bridging action: Connects microflocs to form larger, denser flocs.
Rapid settling: Improves solid-liquid separation and enhances sludge dewatering.
🚀 Key Benefits of PAM:
✅ Works with PAC to improve sedimentation and reduce treatment time.
✅ Enhances sludge dewatering, lowering water content in sludge.
✅ Suitable for a wide range of industries, including textile dyeing, electroplating, papermaking, chemical processing, and pharmaceuticals.
In summary, PAC initiates coagulation, while PAM strengthens flocculation. Together, they significantly improve wastewater treatment efficiency!
Optimal PAC and PAM Dosage Ratios & Application Methods
The correct dosage is crucial for achieving the best treatment results.
1、Standard PAC & PAM Concentration Ratios
📌 PAC solution concentration: 20%-30%
📌 PAM solution concentration: 0.1%-0.5%
📌 Dosing Order:
✔ Add PAC first for coagulation, allowing small flocs to form.
✔ Then add PAM to bind these flocs into larger aggregates for faster settling.
2、Recommended PAC & PAM Dosage for Different Industries
| Industry | PAC Dosage (mg/L) | PAM Dosage (mg/L) | Recommended PAM Type |
| Electroplating wastewater | 150-300 | 0.5-3 | Anionic PAM |
| Papermaking wastewater | 200-400 | 1-5 | Cationic PAM |
| Textile dyeing wastewater | 100-250 | 0.5-3 | Anionic/Cationic PAM |
| Pharmaceutical wastewater | 200-500 | 2-6 | Cationic PAM |
| Domestic sewage | 100-300 | 0.5-2 | Anionic PAM |
Types of PAM & Their Applications
1、Anionic PAM (APAM): Best for Suspended Solids Removal
🔹 Applications: Steel manufacturing, synthetic fiber industry, textile dyeing, electroplating, metallurgy, papermaking.
🔹 Recommended concentration: 0.1%, with a 30-minute stirring time for full dissolution.
🔹 Usage method:
✔ Take 100ml of wastewater, add a small amount of PAC, and stir.
✔ Slowly add APAM solution drop by drop and observe floc formation.
✔ Standard dosage: 1-10g APAM per ton of wastewater.
2、Non-Ionic PAM (NPAM): Best for Dissolved Organics & Weakly Acidic Wastewater
🔹 Applications: Food processing, fermentation industry, low-turbidity wastewater.
🔹 Recommended concentration: 0.1%, with a 90-minute stirring time for full dissolution.
🔹 Usage method: Same as anionic PAM.
3、Cationic PAM (CPAM): Best for Sludge Dewatering
🔹 Applications: Pharmaceuticals, leather tanning, textile sludge, chemical sludge, papermaking, municipal wastewater treatment.
🔹 Recommended concentration: 0.2%, with a 60-minute stirring time before use.
🔹 Usage method:
✔ Take 100ml of wastewater, slowly add CPAM solution drop by drop (0.5ml per dose).
✔ Observe floc size, settling speed, and water clarity to determine the optimal dosage.
✔ Standard dosage: 10-20g CPAM per ton of wastewater.
Conclusion: Optimize PAC & PAM Usage for Maximum Efficiency!
🔹 PAC is responsible for initial coagulation, while PAM enhances flocculation—using both together significantly improves wastewater treatment!
🔹 Different PAM types are suited for different industries—customized dosing is key for optimal results!
🔹 Precise chemical dosing improves treatment efficiency, reduces chemical costs, and minimizes waste!
At Shandong Hychron EnergyTech Co.,Ltd., we specialize in wastewater treatment solutions with 20 years of experience. We provide customized, high-efficiency, and cost-effective treatment plans for various industries.
🚀 Looking to optimize your wastewater treatment process? Contact us for expert consultation and tailored solutions! 📩
