Water there is return to the environment at the secondary treatment is known as

Effluent water

Explanation:

Effluent is a water that is returned to the environment after secondary treatment. It is a liquid waste that is discharged in the sea or river.:)

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint