4.5 out of 12 points Type the answer to parts 6a) and 6b) in the space provided. Submit a PDF scan of all handwritten work for work for part 6c) in the Exam 2 - Handwritten Work submission immediately after the exam. For part 6c), only your handwritten work on this question will be graded. 6. a) Describe the processes of Coagulation and Flocculation in water treatment. (3 points) b) Which are the process steps X and Y (from figure below) of the wastewater treatment process? (3 points) Point A Point B Disinfection followed by Influent screens Grit chamber Primary Electricity Biological treatment clarifier Air C CO2 reuse or discharge X Recycle Screenings to landfill Solids Y c) Considering that the wastewater at point A (see figure above) has a BOD equal to 1000 mg O2/L, what is approximately the BOD value at point B and why? What is the expected value at the output of the plant and why? (6 points) 14 out of 18 points Solve by hand on paper, and enter the numeric answer in the space. Be sure to submit all handwritten work in the Exam 2 - Handwritten Work submission immediately after the exam. 9. Improperly stored industrial waste results in the discharge of chlorobenzene (C6H5CI) into groundwater. Chlorobenzene binds to the solids with a Kd of 1.3 L/kg. The aquifer emerges into a stream 400 m away, over which distance the water table drops by 1.5 m. The sandy soil has a hydraulic conductivity of 7.1 x 10-4 m/s, a porosity of 0.32, and a solids density of 2.1 kg/L. Under these conditions, how long will it take (in years) for chlorobenzene to reach the stream? (18 points) * After entering the numeric answer, please briefly hold up your written work to your webcam.