Activated carbon is a thermally carbonized material typically from wood, coal, coconut shells, peat, petroleum coke, bones or fruit stones. This product features a porous (activated) medium with a high surface area and a high affinity for organic compound immobilization (e.g. pesticides). High turbidity may reduce the treatment efficiency of activated carbon filters.
Moderately expensive. Costs depend on the used materials and the applied activation method.
Applicable at local or semi-centralized level. Activities (like replacing material and monitoring removal performance) can be combined with activities for other processes in chain. Occasionally skilled labor is required for performance assessment step and for treatment of carbon and sludge.
Used carbonaceous materials are possibly locally available. But in case of using wood it might contribute to deforestation. Highly contaminated carbon or sludge from cleaning requires safe disposal. If dumped untreated, leaching may lead to groundwater contamination.
Powdered carbon is dosed in water, requiring post-filtration. Granular carbon is used in filtration bed and is more efficient in use. Reactivation is achieved through the burning off of organic contaminants and requires specialized installations, mostly located elsewhere. Reactivation frequency depends on medium and water quality.
Efficient treatment method with easy acceptance from users. Contamination risk if carbon is not reactivated/replaced in time. As it removes small contaminants invisible to the naked eye, reduced water quality is not necessarily noticed immediately by users.
No relevant remarks for Activated carbon.