Question

Calculate the hardness of water sample (using Azeolite bed exhausted method)

Azeolite bed exhausted by softening of 4000 litres of hard water requires 10 litres of 10%NACl solution for regeneration. Calculate the hardness of water sample.

Answer 1

Solution:

 

Step 1:

Find out of amount of NaCl present in brine solution which is used in process & then convert it in to CaCO3 equivalent.

 

Amount of NaCl consumed by Zeolite bed=10% NaCl= 100 g/ Litre 

 

Step 2:

So,

10 litre solution contain = 10 × 100= 1000 g of NaCl

 

Step 3:

Convert it into CaCO3 equivalent

1000 g of NaCl= 1000 × 50/58.5 g of CaCO3 equivalent= 854.70 g of CaCO3 equivalent.

Zeolite bed on softening 4000 litres of hard water, required 10 litres of 10% NaCl Which is equivalent to 854.70 g of CaCO3 equivalent.

4000 liter hard water contain= 854.70 g of CaCO3 equivalent. 

 

Step 4:

Therefore, 

1 litre \( =\frac{ 854.70\times 1000}{4000} =213.5 \) PPM (mg of CaCO3)

hardness of water sample (using Azeolite bed exhausted method) is 213.5 PPM.

Hardness of water sample by using Azeolite bed exhausted method is 213.5 PPM.