Wastewater Treatment Plants -

: Microbes and bacteria consume the remaining organic matter. Aeration tanks pump in oxygen to keep these "good" bacteria active and hungry.

: The water sits in large clarifiers, allowing heavy solids to settle as sludge at the bottom while oils and grease float to the top for removal.

Modern plants typically follow a multi-stage process to ensure the water is thoroughly cleaned:

: Large debris like rags, plastics, and sand are removed using bar screens and grit chambers to protect the plant's machinery.

: This optional stage uses advanced filters or chemical processes like reverse osmosis to remove specific nutrients (like phosphorus or nitrogen) or microscopic pollutants.