Finland has used lime, CaO, to try to return life to its acidified lakes. Why was lime used?

Question

Finland has used lime, CaO, to try to return life to its acidified lakes. Why was lime used?

Answer 1

lime neutralisation remains by far the most widely applied treatment method. This is largely due to the high efficiency in removal of dissolved heavy metals combined with the fact that lime costs are low in comparison to alternatives. Lime treatment essentially consists in bringing the pH of the raw water to a point where the metals of concern are insoluble. These metals therefore precipitate to form minuscule particles. A separation of these precipitates is then required to produce a clear effluent which meets regional discharge criteria. The solid/liquid separation forms a sludge which, depending on the applied process, can contain 1 to 30% solids by weight. This sludge must be disposed of in an environmentally acceptable manner.

Answer 2

LIME IS AN ALKALINE SUBSTANCE AND AS SUCH WOULD ADD ALKALI TO ACID TO ACHIEVE A STABLE ph.