Question

Question 30 (4 points) Groundwater defined by the following analysis is to be softened by lime-soda ash treatment. The target total hardness is 90 mg/L as CaCO3, in which CH = 40 mg/L as CaCO3 CO2 = 30 mg/L as CO2 = 120 mg/L as Ca2+ Ca2+ Mg2+ = 48 mg/L as Mg2+ Nat = 46 mg/L as Nat HCO3 = 200 mg/L as Cacos SO42- 96 mg/L as SO42- 35 mg/L as CI FORMULA CO2 CaCO3 EQUIVALENT WEIGHT (S/EW) 22 50 20 Ca2+ Mg2+ HCO3 SO42- CI 12.2 61 48 35.5

Answer 1

18) CO2 = 30 mg/ as co2 = 30 meque has coz 22 -1.36 mequinalent al con Ca²+ = 120mg/ as ca 2+ = 120 20 6 12. 48 12.2 HCO3 = 11 so 1 2- = 96 2x so 48 - 2 m mequiualent as ca2t equinalent as cart Mg2+ = 48 mg/L as mg 24 mequiredent as ng at 3.93 mequindlent as Mg 2+ 200mg/L es calo] 200 mequivalent as cacos 4 mequivalent as calos, on equivalent as so, 2- meguinalent astato soq 2- 35 m equirealent as 64kby u- 0-99 m equivalent as sa G- minimum Ivtal hardness, Carbonate hardness = Alkalinity Total Hardness = [ca2+, Mg 2+] 9.93 mequivalent Total alkaliniby - [HCO3) = 4 mequiualent Carbonate hardness, CH = minimum (9.33,4) 4 mequinatent Nom carbonate hardness, NCH - mequindent a- 35 355 - 6 +3:53 - . 9.534 11 5.gg CS Scanned with CamScanner

According to flow Chart: Quantity of time required CO2, HCO,, Mg2+ 1-36 + 4+ 5.93] 750 mg/L as cacos 564-5 mg/ as calo]. 565 mg/l as Cacoa fitrions is - W dll CS Scanned with CamScanner