Cationic polyacrylamide (CPAM) is the go-to flocculant for sludge dewatering, municipal wastewater treatment, and paper manufacturing. This guide covers everything buyers need to know: charge density selection, bulk pricing, and how to source CPAM directly from Chinese factories.
What Is Cationic Polyacrylamide?
Cationic polyacrylamide (CPAM) is a water-soluble polymer with a positive ionic charge. The positive charge allows it to neutralize negatively charged suspended particles — bacteria, organic colloids, and fine solids — causing them to aggregate into large, settleable flocs. For a comparison with anionic types, see our anionic vs cationic PAM guide.
CPAM is produced by copolymerizing acrylamide (AM) with cationic monomers such as DMDAAC or AETAC. The ratio of cationic monomer determines the charge density, which is the most critical specification for application matching.
For projects like this, our CPAM with 40-60% charge density delivers consistent results with factory-direct pricing.
Key Specifications
| Parameter | Typical Range | Effect on Performance |
|---|---|---|
| Molecular Weight | 5–12 million Da | Higher MW = stronger bridging, larger flocs |
| Charge Density | 10–80 mol% | Higher charge = better for high-organic sludge |
| Solid Content | ≥ 90% | Higher solid = less shipping cost per active kg |
| Dissolution Time | 30–60 min | Affects dosing system design |
| Residual Monomer | ≤ 0.1% | Safety compliance for drinking water applications |
Choosing the Right Charge Density
Charge density is the single most important variable when selecting CPAM. Matching charge to your sludge type prevents overdosing (wasted cost) and underdosing (poor dewatering).
| Charge Density | Best For | Typical Dosage |
|---|---|---|
| Low (10–20%) | Inorganic sludge, low-organic wastewater | 3–5 g/m³ |
| Medium (30–50%) | Municipal WWTP sludge, food processing | 5–10 g/m³ |
| High (60–80%) | Activated sludge, high-organic industrial waste | 8–15 g/m³ |
Rule of thumb: If your sludge has high organic content (VSS/TSS ratio > 0.6), start with medium-to-high charge density. For predominantly inorganic sludge (mining tailings, quarry runoff), low charge density is usually sufficient. Learn more about charge density selection.
Primary Applications
1. Municipal Sludge Dewatering
CPAM is the dominant flocculant in belt filter press and centrifuge dewatering systems. A well-matched CPAM can reduce sludge cake moisture content from 85% to 75–78%, cutting disposal costs by 30–40%. Read our detailed municipal sludge dewatering guide for optimization tips.
2. Industrial Wastewater Treatment
Paper mills, textile plants, and food processing facilities use CPAM to clarify process water and dewater production sludge. Typical treatment cost: $0.05–0.15 per m³ of wastewater treated.
3. Paper Manufacturing
In papermaking, CPAM acts as a retention and drainage aid, improving filler and fiber retention on the wire. This reduces raw material loss and improves paper formation. Dosage: 200–500 g/MT of paper produced. See our PAM in paper manufacturing article for details.
4. Oil Sludge Treatment
Oilfield produced water and refinery sludge require high-charge CPAM (60–80%) to break oil-water emulsions and separate suspended solids. For more on oilfield applications, see PAM for oil drilling.
Need PAM for sludge dewatering?
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Bulk Pricing (2026)
CPAM FOB China Price Guide
FCL (20MT+) discounts: 8–12% off listed price. Annual contract (100MT+): 15–20% off.
Packaging Options
- 25 kg kraft bags — Standard export packaging, 40 bags/pallet
- 500 kg jumbo bags — For large-volume buyers with bulk handling equipment
- Custom labeling — OEM/private label available for distributors
All packaging includes: product name, batch number, production date, net weight, and safety information (GHS compliant).
Quality Testing Before Shipment
Every batch of CPAM from ChinaPAM is tested for:
- Molecular weight (viscosity method, Ubbelohde viscometer)
- Charge density (colloidal titration)
- Solid content (gravimetric, 105°C drying)
- Residual acrylamide monomer (HPLC, ≤0.1%)
- Dissolution rate (visual inspection at 0.1% solution)
Certificate of Analysis (COA) is provided with every shipment. Third-party SGS inspection available on request.
How to Order CPAM in Bulk
- Share your application details — sludge type, dewatering equipment, current flocculant (if any)
- Receive product recommendation — we match charge density and MW to your process
- Request free samples — 200–500g for jar testing at no cost
- Confirm order specs — quantity, packaging, shipping terms
- Production and shipment — 7–15 day lead time, COA before loading
Get CPAM Pricing Now
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