ppm as CaCo3

Why ppm as CaCo3 ?

In any water sample - the concentration of minerals/impurities/cation/anions shall analysed in terms on mg/l(ppm - Parts per million). But in order make this values used in calculations for process design and selection. A common unit is is required. There comes the ppm as CaCo3.

Why CaCo3 ?

Calcium Carbonate (CaCO3) with a molecular weight of 100 and an equivalent weight of 50 has been chosen as the reference molecule to represent all the ionic impurities present in water.When the meq/1 of a constituent is multiplied by its equivalent weight,the mg/1 or ppm concentration of the substance is obtained.When the meq/1 of a constituent is multiplied by 50 – the equivalent weight of CaCO3 – the mg/1 or ppm concentration of the substance in terms of CaCO3 is obtained.The ppm CaCO3, like the meq/1, then becomes the common unit of concentration of the constituents of water. This enables comparison of the relative values as also to validate the arithmetical operations of addition and subtraction.

To convert mg/1 of any element to ppm CaCO3 use the following relationship.

ppm CaCO3	=	mg/1 of element	x 50
		equivalent weight of element