Q. Analysis of water gave the following results H₂SO₄ = 196Mg/L; MgSO₄ = 24Mg/L, CaSO₄ = 272Mg/L and NaCl = 25Mg/L. Water is to be supplied to the town of the population of one lake only. The daily consumption of water is 50 Litre per head. Calculate the cost of the cost of Lime soda required for the softening of hard water for town for the month of April 2002. If the cost of lime is Rs.5/-per Kg and soda is Rs.8/-per Kg.

Ans. Calculation of CaCO₃ equivalents

Amount of Lime required: = 74/100[H₂SO₄ + MgSO₄]*Vol. Of water

                                                 = 74/100[200 + 20]*50*100000

                                                 = 814*10⁶ mg = 814 kg/day

Amount of soda required: = 106/100[H₂SO₄ + MgSO₄ +CaSO₄]*Vol. Of water

                                                 = 106/100[200 + 20 + 200]*50*100000

                                                 = 2226*10⁶

                                                 = 2226Kg/day

Cost of lime and soda for the month of April 30 days

Cost of lime = 814*30*5 = Rs. 122100

Cost of soda = 2226*30*8 = Rs. 534240