A jar test is a practical way to compare coagulants and flocculants before full-scale water treatment chemical dosing. It helps buyers and operators compare PAC, PAM and other treatment chemicals using the real water sample.
Basic jar test workflow
- Collect a representative water or sludge sample.
- Prepare chemical stock solutions at controlled concentration.
- Set a dosage range for each beaker.
- Rapid mix to disperse the chemical.
- Slow mix to allow floc growth.
- Allow settling or dewatering observation.
- Compare turbidity, color, floc size, sludge volume and filtrate clarity.
What to record
| Item | Reason |
|---|---|
| Raw water pH | Coagulation is often pH-sensitive |
| Dose | Needed to calculate operating cost |
| Mixing condition | Affects floc formation |
| Settling time | Shows clarification speed |
| Final turbidity/color | Main performance indicator |
| Sludge volume | Impacts handling and cost |
FAQ
Can a jar test replace plant trial?
No. A jar test is a screening method. A plant trial is still useful before large-scale purchase.
Why do lab results differ from site results?
Differences may come from mixing energy, water variation, temperature, dosing accuracy, pH and equipment conditions.