Author(s): J. Sallanko; R. Kamula
Linked Author(s): Riitta Kamula, Jarmo Sallanko
Keywords: Water treatment; Groundwater treatment; Calcium carbonate filter; Iron; Limestone
Abstract: Finnish acidic groundwaters often have excess of iron and manganese causing a need for water treatment. In the small and middle-sized groundwater treatment plants of Finland, biological water treatment is largely used. This method usually includes a combination of dry filtration and slow sand filtration. In some cases, the use of limestone filtration at the end of this process has been taken into use to raise the hardness of water and raise the pH-level. The use of limestone filtration as the first phase in biological groundwater treatment has many advantages. However, the use of wet calcium carbonate filter as the first phase has been nonexistent, if there is iron or manganese in the water. This is due to the fear that calcium carbonate would passivate with time. This paper gives an outline on the Finnish groundwater quality and the means to treat the problematic waters of Bothnia.
Year: 2003