Question

In a sewage treatment plant, grit comprising soil and small pebbles is removed during which stage and process?

Options

• Primary treatment by sedimentation in a grit chamber

• Secondary treatment by agitation in an aeration tank

• Tertiary treatment by chemical chlorination

• Biological treatment by anaerobic digestion

Answer 1

In primary treatment, after sequential filtration removes floating debris, the sewage is passed through a grit chamber where grit (composed of soil and small pebbles) settles down by sedimentation.