Civil Engineering Question 7. You need to design a treatment plant…

Civil Engineering Question 7. You need to design a treatment plant…

Civil Engineering Question

7. You need to design a treatment plant for flowback water from Marcellus Shale drilling. The well produces 1 MGD. The water coming out of the plant contains 200 ppm ultimate BOD with a pH = 6. The first step is to raise the pH of the water to precipitate some of the salts. You are going to mix the flowback water with another stream containing water at a pH of 12 in a CSTR. If you want the combined stream to have a pH of 9.5, calculate the flowrate of the incoming stream. Assume no reaction. (Hint: Do a material balance on OH^–.)