It is a high-basicity, polymeric aluminum chloride-based coagulant and flocculant chemical. With its sulfate content, it enhances the adhesion of floc structures formed in water. Since it contains a low amount of sulfate (SO₄²⁻), it does not leave residual sulfate in water as aluminum sulfate does.
It is widely used as a coagulant in drinking water treatment, wastewater treatment, and process water production plants. Poly-aluminum chlorides are empirically represented by the formula: Alₙ(OH)ₘCl(3n–m) where 0 < m < 3n.
The neutralization degree (basicity) of hydrolyzed Al³⁺ is expressed as the OH/Al molar ratio. This ratio is generally referred to as the ligand number, hydroxyl number, or basicity (r).
For aluminum chloride (AlCl₃), the r ratio is 0.
For aluminum hydroxide (Al(OH)₃), the r ratio is 3.
In polyaluminum chlorides (PACs), the r ratio typically ranges between 0.5 and 2.5.
The higher the r ratio, the more stable the product and the greater the number of polymeric molecules it contains. Therefore, products with a higher r ratio (high-basicity PACs) provide maximum coagulation efficiency.
Polyaluminum chloride solutions are acidic, but their acidity decreases as the r ratio increases. The total aluminum content, expressed as Al₂O₃, provides information about the product composition and activity. The aluminum content of PAC products (as Al₂O₃) generally ranges from 7% to 24%.
Depending on their derivatives, PAC products may contain different inorganic salts, and the presence of these species directly affects the quality and performance of the product.
- Has a strong floc structure.
- Ensures rapid floc formation.
- Reacts easily at low raw water temperatures.
- Reacts easily at low raw water turbidity.
- Provides high COD removal.
- Provides high heavy metal removal.
- Provides high turbidity removal.
- Leaves no residual aluminum (Al³⁺) in treated water.
- Requires lower dosages compared to other coagulants.
- Produces less chemical sludge compared to other inorganic coagulants.
- Effective over a wide pH range.
- Does not alter the pH of the water after coagulation.
- Can be dosed directly without solution preparation.
- Easy to use, store, and dose.
Polyaluminum Chloride Hydroxide Sulfate (PACS)
| Product Form: | Liquid |
| Appearance: | Clear Liquid |
| Active Content: | 10 - 23% Al2O3 |
| Relative Basicity: | 65 - 85% |
| Density: | 1.1 – 1.4 g/cm³ |
| pH (5% Solution): | 3.5 – 5.5 |
| Viscosity: | <50 cps |
