Choosing the right Polyaluminium Chloride (PAC) is one of the most critical decisions in water and wastewater treatment. Using the wrong PAC grade may lead to poor treatment performance, regulatory issues, or even safety risks.
This practical guide explains how to select the correct PAC grade based on water type, treatment goals, compliance requirements, and operating cost.
Step 1: Identify Your Water Type First
The source and purpose of the water determine which PAC grade you must use.
Industrial Wastewater & Municipal Sewage
For:
- Industrial effluent
- Municipal sewage
- High COD, high turbidity water
You should select industrial-grade wastewater PAC.
✔ Strong coagulation
✔ Cost-effective
✔ Suitable for harsh water conditions
👉 Related reading: Wastewater PAC vs Drinking Water PAC
Drinking Water & Potable Water Systems
For:
- Municipal drinking water plants
- Surface water purification
- Human consumption systems
You must use drinking water-grade PAC only.
✔ Low heavy metals
✔ High purity
✔ Complies with potable water standards
👉 Learn more: What is Polyaluminium Chloride (PAC)?
Step 2: Check Regulatory and Safety Requirements
Before purchasing PAC, always confirm:
- National or local drinking water standards
- Heavy metal limits (iron, lead, arsenic)
- Residual aluminum requirements
❗ Industrial PAC does NOT meet drinking water safety standards, even if the coagulation result looks clear.
If your project involves human contact or consumption, drinking water PAC is non-negotiable.
Step 3: Match PAC Grade to Water Quality Conditions
Different raw water conditions require different PAC characteristics.
Key Parameters to Consider
- Turbidity level
- pH range
- Water temperature
- Organic matter content
High-basicity PAC performs better in:
- Low-temperature water
- Low-alkalinity systems
- Rapid floc formation needs
Step 4: Evaluate Dosage Efficiency and Sludge Volume
A common misconception is that lower-price PAC always saves cost.
In reality, total treatment cost depends on:
- Required dosage
- Sludge production volume
- Sludge disposal cost
High-quality PAC often:
- Requires lower dosage
- Produces less sludge
- Reduces downstream handling cost
👉 PAC is often combined with polyacrylamide flocculant to further reduce dosage and improve settling.
Step 5: Choose the Right Physical Form
PAC is available in:
- Powder
- Liquid
Selection Tips
- Powder PAC: lower transport cost, longer shelf life
- Liquid PAC: easy dosing, faster dissolution
Choose based on:
- Storage conditions
- Dosing system
- Operation convenience
Step 6: Always Test Before Bulk Purchase
Before full-scale use, perform:
- Jar test
- Small pilot test
- Dosage comparison
Testing helps confirm:
- Optimal PAC type
- Ideal dosage range
- Compatibility with existing systems
Common Mistakes Buyers Should Avoid
❌ Choosing PAC based on price only
❌ Using wastewater PAC for potable water
❌ Ignoring heavy metal content
❌ Skipping jar tests
These mistakes often lead to:
- Unstable water quality
- Equipment fouling
- Compliance risks
Conclusion: The Right PAC Grade Protects Performance and Safety
Selecting the correct PAC grade is not just a technical issue — it is a cost, safety, and compliance decision.
✔ Match PAC grade to water type
✔ Follow safety standards
✔ Optimize dosage, not just unit price
✔ Test before scaling up
A well-selected PAC ensures stable water quality, lower operating cost, and long-term reliability for your treatment system.
