1.Soda Lime Process 2.Base exchange process ( Permuted ) 3.Demineralization 4.Soda Alum 5.Aceration 6.Chelation on sequestration.   Soda Lime Process: In this process, Hydrated lime and sodium carbonate are added to precipitate calcium and magnesium ions as compounds of low solubility. For temporary hardness, Ca(HCO3)2+Ca(OH)2 ———–à 2CaCO3↓+2H2O Mg(HCO3)+2Ca(OH)2 ———à 2CaCO3↓+Mg(OH)2+2H2O For Permanent Hardness, CaSO4+NaCO3 ————–à …