GAC (Granular Activated Carbon)

GAC is proven, tolerant of variable feed water, and addresses several risks at once: pesticides, organics, taste, odour, and disinfection by-product precursors. It also acts as a safety barrier against unexpected catchment contamination, which is why many works retain GAC as a final polishing stage.

Empty bed contact time (EBCT) is the time water would take to pass through the carbon volume if no carbon were there: bed volume divided by flow. It is the key design parameter. Taste and odour duties use 5 to 10 minutes, pesticides 10 to 20 minutes, and PFAS typically 15 minutes or more.

Yes. RSE regularly installs ceramic plant alongside or in place of existing filtration, reusing the intake, coagulation, contact tanks and clean water storage where they remain fit for purpose. Because our modular units arrive fully tested, disruption to the operating works is kept to a minimum.

RSE delivers modular GAC from small rural supplies of a fraction of a megalitre a day, up to major works handling tens of megalitres a day. Larger duties use multiple vessels in parallel allowing one vessel to be taken offline for changeout without losing output.

Yes. Spent carbon goes to a thermal reactivation facility, which burns off the adsorbed organics and returns the carbon to service, typically with a loss of 5% to 10% each cycle. Reactivation costs less than virgin carbon and cuts embodied carbon. PFAS-loaded carbon needs a facility licensed to destroy those compounds.

Standard modular GAC units are typically delivered in 6 to 12 months from order, and repeat builds faster. Because the vessels, pipework, valves and controls are assembled and tested off- site, installation and commissioning normally take a few weeks.