Determine the exact and approximate alkalinity of a water sample that contains 120.0 mg/L of (CO3)^2- and 75.0 mg/L of (HCO3)^- at a pH of 9.7 at 25 degrees Celcius

1. The following information is provided for an activated sludge system design: Parameter Symbol Value Units Flow rate Q 10000 m³/d Influent BOD So 150 mg/L Effluent BOD S 2 mg/L Hydraulic residence time Ꮎ 4 hr Mean cell residence time Oc 6 d Maximum specific growth rate μm 3 1/d Half saturation constant Ks 40 mg/L Yield coefficient Y 0.5 Endogenous decay coefficient b 0.08 1/d Death rate coefficient γ 0.04 1/d Determine: a) The aeration tank biomass concentration (X) in mg/L b) The aeration tank oxygen requirement in kg/d c) The rate of biomass wasting in kg/d

The analysis of water quality from an artesian well presented the result Alkalinity atbicarbonates equal to 24 (mg/L CaCO3), the pH of 7.0, the concentration of Ca+2 equal to 14 mg/L and theMg+2 concentration equal to 20 mg/L.Knowing that the equivalent weight of CaCO3 is equal to 50, of Ca+2 equal to 20 and of Mg+2 equal to 12.It is concluded that the permanent and temporary hardness, respectively, are: (A) 24mg/L (CaCO3) e 118 mg/L (CaCO3).(B) 94 mg/L (CaCO3) e 24 mg/L (CaCO3).(C) 24 mg/L (CaCO3) e 94 mg/L (CaCO3).(D) 94 mg/L (CaCO3) e 118 mg/L (CaCO3).

From water sample, 25 mg/L HCO3" as CacO3, 10 mg/L C032 as Caco3 and 50 mg/L Ca* as CaCO3 were measured. pH was near neutral. What is alkalinity? () mg/L as Cac03 (*Answer in whole number only)