ABSTRACT

Dissolved silica is removed from lake water through its co-precipitation with hydrated oxides of iron and manganese. Dissolution of hydrated oxides of iron and manganese (orange floccules) including co-precipitated silica in the bottom sediment of lake causes a simultaneous increase in the dissolved silica content with increase in the dissolved iron and manganese contents of hypolimnionic water. The behavior of dissolved silica is thus controlled by the oxidation-reduction cycle in lake water.