Polyaluminium Chloride, Aluminum Hydroxychloride, Aluminum Chlorohydrate, PAC 10, PAC 17, PAC30, 1327-41-9, 101707-17-9

Polyaluminium Chloride, Aluminum Hydroxychloride, Aluminum Chlorohydrate, PAC 10, PAC 17, PAC30 Powder, 1327-41-9, 101707-17-9

Polyaluminium Chloride (PAC)

1. Chemical Identity

• Names: Polyaluminium Chloride (PAC), Polyaluminium Hydroxychloride, Aluminum Chlorohydrate

• CAS Numbers:

  • 1327-41-9 → Standard PAC (most common in water treatment)

  • 101707-17-9 → Polyaluminium Hydroxychloride

  • 11097-68-0 → Aluminum Chlorohydrate (cosmetics/antiperspirants)

  • 114442-10-3 → Other basic aluminum chloride derivatives

• Forms:

  • Powder (PAC30, ~30% Al₂O₃)

  • Liquid (PAC10, PAC17)

• Appearance: Yellow, grey, or white powder / cloudy liquid

• pH (1% solution): 3.5 – 5.0

2. Mechanism of Action

PAC works through three main steps in water treatment:

• Coagulation: Neutralizes particle surface charges, destabilizing colloids.

• Flocculation: Destabilized particles aggregate into larger flocs.

• Sedimentation: Flocs settle under gravity, clarifying the water.

Its high adsorption capacity and wide pH tolerance make PAC effective without requiring additional chemicals.

3. Applications and Dosage Ranges

4. PAC30 Powder Preparation

• Stock Solution: Dissolve PAC30 powder in clean water to prepare a 5–10% solution.

• Mixing: Stir gently; avoid excessive mechanical energy that may break flocs.

• Application: Dose the stock solution into the system using metering pumps.

• Stability: Prepare fresh solutions; do not store for long periods.

5. Advantages

✔ High coagulation and flocculation efficiency ✔ Effective across a wide pH range ✔ Lower sludge production compared to alum ✔ Fast solubility and low dosage requirement ✔ Effective in removing arsenic and fluoride

6. Precautions

• Always determine dosage via jar tests before application.

• Overdosing may leave residual aluminum and cause environmental impact.

• Follow local regulations and safety guidelines.

• Store PAC powder in dry, sealed conditions to prevent moisture absorption.

PAC Powder (PAC30) and liquid PAC grades (PAC10, PAC17):

1. Composition & Form

2. Preparation & Handling

• PAC30 Powder

  • Must be dissolved in water before use (typically into a 5–10% stock solution).

  • Requires controlled mixing to avoid lump formation.

  • Easier to transport in bulk (lower volume, higher concentration).

• PAC10 / PAC17 Liquids

  • Ready-to-use, no dissolution step required.

  • Easier dosing with metering pumps.

  • Heavier to transport due to water content.

3. Dosage & Application

• PAC30 Powder

  • More concentrated, so lower dosing volume is needed.

  • Typical dosage: 5–50 mg/L for drinking water, 20–200 mg/L for wastewater.

• PAC10 / PAC17 Liquids

  • Higher dosing volume required due to lower Al₂O₃ concentration.

  • PAC17 is more efficient than PAC10, but both are less concentrated than PAC30.

4. Advantages & Limitations

• PAC30 Powder ✔ High concentration → economical in transport & storage ✔ Lower sludge production compared to alum ✘ Requires dissolution step before use ✘ Sensitive to moisture during storage

• PAC10 / PAC17 Liquids ✔ Easy to handle and dose directly ✔ No dissolution step needed ✘ Higher transport/storage cost (more water content) ✘ Larger dosing volume required

Summary:

• PAC30 Powder is best for large-scale plants with solution preparation facilities, offering cost efficiency and high concentration.

• PAC10 and PAC17 Liquids are more convenient for smaller systems or where direct dosing is preferred, though they require more volume for the same effect.