Index >> Waste Water Microbiology >> Excess Lime Soda Softening

Excess Lime Soda Softening - This method is employed for all forms of magnesium hardness. This process is a complicated one and uses lime and soda ash. A characteristic of all these precipitation process is the production of large volumes of sludge. Lime can be removed from the sludge by heating CaCO₃ and then adding water.

CaCO3 → Ca O + CO2

Ca O + H2O → Ca (OH)2

Thus, calcium hydroxide regeneration reduces sludge disposal problem.