I. Multiple Choice One (best) choice only; circle the letter; be sure final choi
ID: 702563 • Letter: I
Question
I. Multiple Choice One (best) choice only; circle the letter; be sure final choice is clear (4 points each) 1. A United States federal law that controls the air pollution a) on a national level is: Superfund Air Act The Clean Air Act (CAA) c) The Resource Conservation and Recovery Act (RCRA) d) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) 2. When impurities are removed from water through settling out by gravity, the process is called a) Coagulation b) Sedimentation c) Filtration d) Disinfection 3. Which process of water treatment is done to avoid floating debris, branches, trees or other la suspended in water? a) Screening b) Aeration c) Coagulation d) Flocculation What is formed after a coagulant is added to water? a) Scum b) Soap c) Bubbles d) Flocs 4.Explanation / Answer
1) b) US Federal law that controls air pollution at national level is 'The Clean Air Act'.
2) b)
Sedimentation is the process removing impurities from water by allowing them to settle down under gravity in a still tank.
3) a)
Screening is a simple process to remove large particles, materials etc from water by passing the water through a screen .
4) d)
On addition of coagulant, the charged particles in water get neutralized and form microflocs.