Multiple choice

The first step of sewage treatment is

  1. precipitation

  2. chlorination

  3. sedimentation

  4. aeration

  5. eutrophication

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sedimentation is a physical water treatment process using gravity to remove suspended solids from water. Solid particles entered by the turbulence of moving water may be removed naturally by sedimentation in the still water of lakes and oceans.