Poly Aluminium Chloride (PAC), chemical formula Al₂(OH)ₙCl₆₋ₙ·xH₂O where n ranges from 1 to 5, is an inorganic polymer coagulant that combines the properties of aluminium hydrolysis products with chloride anions. PAC has largely replaced conventional aluminium sulphate (alum) in water and wastewater treatment due to its superior performance characteristics, particularly in cold water conditions and at lower natural pH values.
PAC is available in both liquid form (10% Al₂O₃ content) and powder/solid form (28–30% Al₂O₃ content). The basicity of PAC, a measure of the degree of hydroxyl substitution, determines its performance characteristics and suitability for specific applications. Higher basicity grades produce less residual acidity and generate smaller sludge volumes.
PAC vs Alum: PAC delivers 30–50% better coagulation efficiency compared to conventional alum, operates effectively over a pH range of 5–9, generates 30–40% less sludge, and provides faster settling, directly reducing operational costs in water treatment plants.
| Application | PAC Grade | Key Benefit |
|---|---|---|
| Drinking Water Treatment | High basicity, NSF-certified | Low residual aluminium, meets potable water standards |
| Industrial ETP | Medium basicity | TSS, turbidity, and COD removal |
| Paper & Pulp Industry | Low basicity (acidic pH) | Fibre retention, resin sizing, white water clarification |
| Textile Effluent | Medium / High basicity | Colour, COD, and TSS reduction |
| Mining (Tailings) | Low basicity | Rapid settling of fine mineral particles |
| Swimming Pool Water | High basicity liquid | Rapid clarity improvement, reduced turbidity |
| Parameter | Liquid PAC | Powder PAC |
|---|---|---|
| Al₂O₃ content | 9 – 11% | 28 – 30% |
| Basicity range | 40 – 90% | 40 – 90% |
| pH (1% solution) | 3.5 – 5.0 | 3.5 – 5.0 |
| Appearance | Yellow to amber liquid | Light yellow to white powder |
| Iron (Fe) content | ≤ 0.5% | ≤ 0.5% |
| Arsenic (As) | ≤ 2 ppm (drinking water grade) | ≤ 2 ppm (drinking water grade) |
| Typical dosage | 5 – 100 mg/L | 5 – 50 mg/L (dissolved) |
| Packaging | 50 L / 200 L drums, tanker | 25 kg / 50 kg bags |
Contact us for jar test data, COA, and competitive pricing for liquid or powder PAC grades.