Certified low-ash carbon for drinking water — taste, odour and trace organics removed without adding anything back to the finished water.
The source water sets the grade, and the source water changes with the season.
Surface water arrives with natural organic matter, seasonal taste-and-odour events driven by algal metabolites, and disinfection by-product precursors. Groundwater arrives cleaner but can carry specific trace contaminants at very low concentrations. The two demand different pore structures, and a plant that draws from both has to specify against the harder case rather than the average one.
950–1,100
mg/g Iodine
Typical iodine number for granular potable grades in service.
The carbon is one stage in a train, not the whole of it.
A full analysis across the seasonal range, not a single sample. Grade selection is made against the worst case the plant has to treat, not the annual mean.
Empty bed contact time, depth and velocity are fixed together from column data, so the mass transfer zone stays well inside the bed at the design flow.
A new bed is backwashed and rinsed to remove fines and stabilise pH before it is put into supply, and the first water is sampled rather than assumed.
Outlet and intermediate sampling track the breakthrough front, so the changeout is planned against data rather than reacted to after a compliance sample.
The grades that fit potable water grade — and what each is good at.
Coconut · acid washed · 8x30
The default for polishing duty. High micropore volume for trace organics, very low ash, and hardness that keeps fines out of the treated water.
Bituminous · washed · 12x40
Broader pore structure for surface waters carrying organic matter and colour, and the grade of choice where the bed will be reactivated.
Milled · dosed
Dosed for seasonal taste-and-odour events at plants without a contactor, or as a supplement when an event exceeds what the bed can hold.
What each property actually governs once the bed is running.
Capacity for the small organic molecules that dominate taste, odour and trace contaminant duty in drinking water.
What can leach into the finished water. Acid-washed grades sit at the low end, and the figure is released on every lot.
Governs fines generation over a long service life, and therefore turbidity carried forward from the bed after backwash.
Balances the mass transfer zone against head loss, within whatever the existing underdrain will retain.
Tested and declared so the treated water can be certified without retesting the supply at the far end of the plant.
Determines the actual carbon mass in the delivered tonnage, which is what a fill quantity should be reconciled against.
Acid washing to remove soluble mineral matter, a low and declared ash content, tested extractables, and the certification documentation to support use in drinking water. The adsorption performance may be similar to an industrial grade; the difference is in what it does not add to the water.
Typically one to three years, depending on the organic load, the contact time and the breakthrough definition applied. It is planned from column data and confirmed by monitoring rather than estimated from a capacity figure.
A warm bed with adsorbed organic matter will develop a biofilm, and in biological filtration that is deliberate and useful. Where it is not wanted, it is managed through backwash regime, contact time and the disinfection stage that follows the bed.
Usually before final disinfection, so it removes precursors rather than the disinfectant residual itself. Where it is used to dechlorinate ahead of membranes, it sits after chlorination by design and the contact time is much shorter.
Often yes, if the bed is sized against the seasonal peak. Where the peak is short and extreme, supplementing a fixed bed with powdered dosing during the event costs less than sizing the entire installation for a few weeks a year.
Send the source water analysis, the compliance regime and the vessel details, and we will come back with the grade, the bed size and the changeout interval.
