After the screens, wastewater flows on into settling tanks, which have chambers where grease, sand and some organic materials are removed. Here the water slows down and pollutants begin to settle to the bottom. These tanks are fitted with a lamellar construction, which you can picture as a honeycomb with fine chambers slanting downwards. This fills the whole space below the surface and is designed to intensify and accelerate the settling process.
At the bottom of the tank, machinery sweeps the settled sludge into a collection sump, while up at the surface skimmers capture the precipitated grease. This stage of treatment removes 50–70% of the solid pollutants before the wastewater leaves mechanical pre-treatment and flows straight into the biological stage.
… that the treatment plant is designed to withstand a 500-year flood?
If you want to know more, continue to other parts of the treatment plant ...
