Purification of water by activated carbons from apricot stones, lignites and anthracite

High efficiency activated carbons with various chemical characteristics, appropriate for the purification of waste and potable water with different pollutions (trihalomethanes, metal ions) were prepared. A suitable selection of both raw materials and activating agents as well as an additional modification were used for this purpose. It is established that activated carbon obtained from apricot stones by pyrolysis in a flow of water vapour (PWV method) can be used for removal of trihalomethanes from water treated with chlorine. Activated carbons obtained from apricot stones and lignites by the same method as well as oxidized anthracite can be used for removal of Pb2+ and Zn2+ ions from potable water. The chemical character of these carbon surfaces favours to a larger extent hemosorption of metal ions. Carbon obtained by steam-activation when used for water purification promotes the formation of nitrites. This hindrance can be eliminated by a suitable oxidation treatment of the carbon.