Powdered Activated Carbon (PAC): Dosing and Application Guide
Powdered activated carbon (PAC) is carbon ground so that ninety percent of its particles fall below 45 microns. The fine particle size gives it a superpower: thanks to the huge external surface, adsorption completes within minutes. That is why PAC is the first choice for batch processes and sudden contamination events.
Where does PAC shine?
- Decolorization: clarifying sugar syrup, glucose, fruit juice and vegetable oils
- Taste and odor control: seasonal geosmin and MIB odor issues in drinking water
- Wastewater: dosing flexibility for organic loads that strain discharge limits
- Flue gas: in-duct injection for dioxin and furan capture
PAC’s greatest advantage is flexibility: it requires no fixed filter investment and is dosed as needed. For processes with variable contaminant loads, that means serious cost control.
Finding the right dose: the jar test
PAC dosing is determined by jar testing, not guesswork. Incremental doses are applied to a water sample, the target parameter — color, odor, TOC — is measured, and the knee of the cost-performance curve is found. Typical doses run 5–25 mg/L in drinking water and much higher in product decolorization. Contact time is usually 15–45 minutes; insufficient contact wastes the carbon’s capacity.
Which specifications matter?
| Parameter | What it shows |
|---|---|
| Methylene blue (180+ ml/g) | Capacity for mid-size molecules and color |
| Iodine number (800+ mg/g) | Capacity for small molecules |
| Particle size distribution | Balance of adsorption speed and filterability |
| Moisture and ash | Product purity and effective carbon fraction |
Wood or coal based?
Wood-based PAC excels at large color molecules thanks to its macropores; it is the classic of food applications. Coal-based PAC, with its economical profile, is common in wastewater and flue gas lines. If undecided, request samples of both from our powdered product family and run a jar test in your own process.
If you run continuous-flow lines, granular carbon may be more economical — read our comparison GAC vs PAC.
