Abiotic because biotic is living. So abiotic is the opposite.
Is there anything else that goes with this question? I’m not sure how to answer.
Answer:
Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment. Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface.
Explanation:
Hope that helps:)
