What is the difference between CPAM and PAC?
2026-04-14 10:46:51
CPAM(Cationic Polyacrylamide)and PAC(Polyaluminum Chloride)are both commonly used in water treatment,but they belong to completely different types of chemicals with different working mechanisms,applications,and usage scenarios.They are often used together,not as substitutes.
1.Basic Category
CPAM:Organic polymer flocculant
PAC:Inorganic coagulant
2.Working Principle
CPAM:Uses charge neutralization+adsorption bridging
Positive charges neutralize negative colloids;long molecular chains bridge particles into large flocs.
PAC:Uses hydrolysis charge neutralization+sweeping precipitation
Releases aluminum ions to neutralize charges and form hydroxide flocs that trap impurities.
3.Main Applications
CPAM:
Sludge dewatering(most important)
Organic-rich wastewater treatment
Removal of oils,proteins,colloids
PAC:
Turbidity removal in river/lake water
Preliminary wastewater clarification
Drinking water purification
Removal of suspended solids and color
4.Dosage
CPAM:Very low dosage—1–10 ppm
PAC:Relatively high dosage—50–200 ppm
5.Dissolution
CPAM:Needs to be dissolved into dilute solution,takes 40–90 minutes
PAC:Dissolves quickly,usually 3–5 minutes
6.Floc Strength
CPAM:Forms strong,tough flocs that resist shearing
PAC:Forms loose,fragile flocs
7.pH Adaptability
CPAM:Best at pH 4–8
PAC:Effective at pH 5–9
8.Typical Matching Usage
In most wastewater plants:
First add PAC to destabilize particles
Then add CPAM to bridge into large,dense flocs
This combination achieves the best clarification and dewatering effect.
References
GB/T 7714
Wang H,Li S,Zhang Y.Comparison and combined application of CPAM and PAC in water treatment.Industrial Water Treatment,2022,42(5):52–56.
MLA
Wang,H.,S.Li,and Y.Zhang."Comparison and Combined Application of CPAM and PAC in Water Treatment."Industrial Water Treatment,vol.42,no.5,2022,pp.52–56.
APA
Wang,H.,Li,S.,&Zhang,Y.(2022).Comparison and combined application of CPAM and PAC in water treatment.Industrial Water Treatment,42(5),52–56.
