Where does poop go after flushing?

(Camilo Solano/)

1. After flushing, the poop travels through interconnected pipes, which collect sewage from across the city, to a treatment plant. There, the waste is treated in two phases: liquid and solid. The sewage treatment process, from the moment it arrives at the station until it turns into clean water, takes approximately 15 hours

two. At the station, the sewage passes through a series of grids, one more closed than the other, which are responsible for retaining larger objects – plastic, paper and everything that people should not flush down the toilet.

3. The second step removes sand and other heavy particles, which remain at the bottom of the tank after the decanting process. The leftover liquid goes into a container with air bubbles, which boost the activity of bacteria, which consume the organic material and reduce the polluting load.

4. Meanwhile, the solid part turns into a kind of sludge and goes through equipment that increases its density. Microorganisms are introduced into the compost and feed on the leftover organic matter. At this stage, the material no longer has a bad smell.

5. At the end of the treatment process, the liquid part is already 90% clean. This water cannot be consumed and is discarded in rivers, without risk of polluting, or it becomes reuse water, which is used by industries

6. Finally, the sludge is filtered and pressed. The final product is sent for dehydration, forming cakes (something similar to dry clay), and then goes to a sanitary landfill. Curiosity: In the metropolitan region of São Paulo alone, an average of 16,400 liters of sewage are treated per second

Reader Question – Clarissa Oliveira, Teixeira de Freitas, BA

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