Activated carbon is one of the most widely used technologies in drinking water and process water treatment. Its extremely high internal surface area adsorbs dissolved organic compounds that conventional coagulation and filtration leave behind — the compounds responsible for taste, odour, colour and many regulated contaminants.
We supply both granular and powdered grades from the manufacturers we have qualified, at manufacturer direct pricing. Which grade suits a plant depends on the contaminant, the contact time available and the existing filter configuration.
What activated carbon removes from water
In municipal drinking water, activated carbon is most often specified for taste and odour episodes, for dechlorination ahead of membranes or ion exchange, and for reducing the dissolved organic carbon that forms disinfection by-products downstream.
- Taste and odour compounds
- Geosmin and 2-methylisoborneol (MIB), the earthy-musty compounds produced during algal blooms, are detectable at nanogram-per-litre levels and are adsorbed effectively by carbon.
- Chlorine and chloramine
- Carbon dechlorinates by catalytic reduction rather than adsorption, which is why it is standard pre-treatment ahead of reverse osmosis membranes that chlorine would damage.
- Disinfection by-product precursors
- Removing natural organic matter before disinfection reduces formation of trihalomethanes and haloacetic acids.
- Synthetic organic compounds
- Pesticides, herbicides, industrial solvents and a range of trace organics adsorb well onto properly selected grades.
Granular vs. powdered
Granular activated carbon (GAC) is used in fixed beds — either as a post-filter contactor or as a replacement for sand in existing filters. It runs continuously for months to years and can often be reactivated rather than replaced, which matters to operating cost at scale.
Powdered activated carbon (PAC) is dosed directly into the water and removed with the sludge. Because it is added only when needed, it suits seasonal problems such as an algal bloom, and it requires no capital work to start using.
How buyers specify it
Water treatment carbon is normally bought against measurable parameters rather than by brand. The ones that appear on most specifications are:
- Iodine number
- A measure of micropore volume, and the most common single indicator of capacity for small molecules.
- Mesh size
- Controls pressure drop and the rate of adsorption. 8x30 and 12x40 are common in water service.
- Apparent density
- Determines how much carbon a vessel of a given volume holds, and therefore bed life.
- Abrasion number
- Predicts how well the carbon survives backwashing, transport and reactivation.
Choosing a base material
We source wood-, coal- and coconut-shell-based products. Coconut shell carbon is highly microporous and performs well on small molecules such as chlorine and light organics. Bituminous coal-based carbon carries a broader pore distribution that suits mixed organic loads and is widely used in municipal contactors. Wood-based carbon is more mesoporous, which favours larger molecules and colour bodies.
Matching the base material to the contaminant is the single decision with the largest effect on bed life. We are glad to talk through a specific water analysis before anything is quoted.
Common questions
What is the difference between GAC and PAC?
Granular activated carbon (GAC) sits in a fixed bed and treats water continuously for months or years, and can often be reactivated. Powdered activated carbon (PAC) is dosed into the water and removed with the sludge, which suits intermittent problems such as seasonal taste and odour episodes and needs no capital work to begin.
Does activated carbon remove chlorine?
Yes. Carbon removes free chlorine by catalytic reduction rather than by adsorption, converting it to chloride. This is why activated carbon is standard pre-treatment ahead of reverse osmosis membranes and ion exchange resins that chlorine would otherwise damage.
Which carbon is best for taste and odour?
Taste and odour compounds such as geosmin and MIB are small molecules, so highly microporous carbons — typically coconut shell or a suitable bituminous grade — are usually specified. The right choice depends on what else is in the water, since competing organic matter occupies the same pores.
Can spent water treatment carbon be reactivated?
Granular carbon can often be thermally reactivated and returned to service, which reduces both cost and waste compared with replacement. Whether it is practical depends on the contaminants adsorbed and the volume involved.
Tell us what you are treating and we will match the grade before quoting.
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