PROCESS DESCRIPTION

Raw waters, such as from reservoirs or wells in granite, sandstone or basalt areas, can be very soft (not infrequently below 3 °dH) and therefore corrosive. The constantly increasing amounts of drinking water desalted by reverse osmosis or distillation also have very low buffering capacity and without further treatment are very corrosive. By increasing the hardness to at least 3 °dH, corrosion in the pipe networks and at the consumer can be avoided. In practice, the degree of hardness is set to a value of up to 8 °dH in order to be able to mix drinking water from several waterworks into the distribution network.