A groundwater contains the following components: Ca2+ = 240 mg/L as CaCO3, Mg2+ = 135 mg/L as CaCO3, H2CO3 = 30 mg/L as CaCO3 and alkalinity = 315 mg/L as CaCO3. The treated water should have a Mg2+ concentration of 40 mg/L as CaCO3 and a total hardness of 100 mg/L as CaCO3. The drinking water flow rate is 1 m3/s.

a) Estimate the daily lime requirement (kg/d)

b) Estimate the daily soda ash requirement (kg/d)

c) Estimate total daily CO2 requirement for water stabilization (kg/d)

d) Estimate the daily sludge production (kg/d)