Sewage Treatment
Chemistry: AQA GCSE Higher, topic 10.1.9
Sewage Treatment
To avoid polluting our environment, we must treat sewage before letting it return into the environment. The steps in the sewage treatment process are:
Screening
- Sewage is examined to remove grit and any large items, such as plastic bags.
Sedimentation
- Sedimentation results in the separation of sewage into heavier sludge and lighter effluent.
Sludge vs effluent
- The sludge is anaerobically digested by bacteria.
- The effluent is aerobically digested by bacteria.
Test yourself on Sewage Treatment
A plastic bottle enters the sewage system. At which stage of sewage treatment would it most likely be removed?
Select the true statement about sewage treatment
A sample of liquid separates from sludge during sewage sedimentation. Which process would be used to break down this liquid?
Which product of sewage sedimentation floats above the other because it is less dense?