LIME SODA PROCESS- Principle:: Calculated quantity of lime & soda are added to hard water to convert soluble impurities into insoluble one which are easily removed by filtration. Reactions are as follows.

i) Removal of temporary hardness-

Ca$(HCO_{3})_{2}$+Ca$(OH)_{2}\rightarrow 2CaCO_{3} \downarrow +2H_{2}O$

Mg$(HCO_{3})_{2}$+2Ca$(OH)^{\rightarrow}_{2} Mg(OH)_{2}\downarrow+2CaCO_{3}\downarrow+2H_{2}O$

ii)Removal of permanent hardness-

$MgCl_{2}+Ca(OH)_{2}\rightarrow Mg(OH)_{2}\downarrow …