How much alkalinity (as CaCO3) is consumed by a dose of 50 mg/L of each of the following coagulants:            Al2(SO4)3 . 14.2 H2O FeSO4 . 7H2O FeCl3 Fe2 (SO4)3

A drinking water treatment plant wants to compare the efficacy of three different solid coagulants, Alum [Al(OH)3(s)], Lime (CaCO3(s)), and Ferric Chloride (FeCl3(s)), for removing the phosphate (PO43-) level to 1 mg/L. The following are the equilibrium reactions [and the respective equilibrium constants (or solubility products, Ksp)] that result in phosphate removalfor each solid, the second reaction being more relevant in each case: Alum: Al(OH)3(s) ↔ Al3+ + 3OH-           AlPO4(s) ↔ Al3+ + PO43-                                     Ksp = 9.84 x 10-21   Lime: CaCO3(s) ↔ Ca2+ + CO32-           Ca3(PO4)2(s) ↔ Ca2+ + PO43-                              Ksp = 1 x10-27   Ferric Chloride: FeCl3 (s) ↔ Fe3+ + 3Cl-                           Fe(PO4)(s) ↔ Fe3+ + PO43-              Ksp = 1x10-26.4 What concentrations of Fe 3+, Al3+, and Ca2+ will be needed to maintain a phosphate concentration of 1 mg/L? What would be the best choice of solid coagulant for the Drinking Water Treatment Plant?…

Which group of constituents is considered nutrients? Nitrate, chloride, and ammonia O Phosphorous, heavy metals, and coliform organisms Ammonia, sulfate, and orthophosphate Ammonium, Org-Nitrogen, orthophosphate

(iii) If HOCI (hypochlorous acid) degrades in water per first-order kinetics with a rate constant of 0.12/d. the initial concentration of HOCI is 12 mg/L (a) How long does it take to be reduced to 0.8 mg/l ? (b) what would be concentration after 4 hours? (6)