2. The raw water to be coagulated has a pH of 7.5, determine how much alkalinity the water must have for the addition of 150 mg/L alum without affecting the pH.

A sample of water at pH 10.5 has 36 mg/L of CO3-2 and 26 mg/L of HCO3-Including the contribution of [H+] and [OH-], find the alkalinity as CaCO3.

Which of the following is not a piece of EPA legislation designed to protect the environment? Clean Water Act Clean Air Act O Civil Rights Act ORCRA D Question 2 What water contaminant was responsible for the 2014 Flint, Michigan water crisis? O Mercury Lead O PCB Giardia Question 3 What condition must be satisfied for us to use the Continuously Stirred Tank Reactor (CSTR) approach? Uniform well-mixed conditions Mixing occurs only in the axial direction The substance is conservative There is only one inflow channel D Question 4 A plug flow reactor is O Less efficient at removing pollutants than a CSTR Has the same efficiency at removing pollutants as the CSTR More efficient at removing pollutants than a CSTR Can be more or less efficient than the CSTR depending on the pollutant