A groundwater (GW) was analyzed for ions and the results are reported below: Ca2+ = 200 mg/L (as Ca2+) Mg2+ = 60 mg/L (as Mg2+) Alkalinity = 400 mg CaCO3/L Assume the pH is near neutral a) What is the total hardness of the GW in mg CaCO3/L? b) What is the non-carbonate hardness of the GW in mg CaCO3/L? c) What is the carbonate hardness of the GW in mg CaCO3/L?? d) Would you recommend the GW be treated with a softening process prior to distribution to consumers? Why? List two treatment options.

Answer is given below.

Explanation:

Alkalinity = 400 mg/L in terms of CaCO3  

a.) Total Hardness is defined as the sum of calcium and magnesium iion concentration in terms of CaCO3

Total Hardness = [Ca+2]*{50/20) + [Mg+2]*{50/12) = [200]*{50/20) + [60]*{50/12) = 750 mg/L in terms of CaCO3

b.) Non-Carbonate hardness = Total Hardness - Carbonate Hardness

Now here as the Total Hardness is greater than alkalinity ,Thus

Carbonate Hardness = Alkanlinity = 400 mg/L in terms of CaCO3

Non-Carbonate hardness = 750 - 400 = 350 mg/L in terms of CaCO3

c.) As Total hardness is greater than Alkalinity thus Carbonate hardness is equal to the Alkalinity.

Carbonate hardness = 400 mg/L in terms of CaCO3

d.) Now as the Total hardness of the ground water is more than 180 mg/L,Thus it needs removal of hardness.

There are many treatment options for the removal of hardness:

i) Ion Exchange method

ii) Lime soda method

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

am i too late?

explanation: