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primary clarifier
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Estimated battle casualties, Normandy invasion, World War II. WWII, D-Day
Estimated Battle Casualties During the Normandy Invasion and Campaign to Liberate Paris (June–August 1944)
Portion of the Aleppo Codex, a manuscript of the Hebrew Bible written in the Hebrew language in the 10th century CE; in the Shrine of the Book, Israel Museum, Jerusalem.
Why Do Languages Die?
San Francisco, California/USA-1/18/20: Womens March at Civic Center marching with signs of political protest regarding equality also embracing 2020 presidential candidates and celebrating equality
How Does the U.S. Government Define the Difference Between a Protest and a Riot?
Time zone map with standard time zones and International Date Line
Why Are Some Time Zones 30 Minutes Off Instead of an Hour?
Wasp spider. Argiope bruennichi. Orb-weaver spider. Spiders. Arachnid. Cobweb. Spider web. Spider's web. Spider silk. Black and yellow striped wasp spider spinning a web.
Do We Really Swallow Spiders in Our Sleep?
Lake Mead (the impounded Colorado River) at the Hoover Dam. The light-coloured band of rock above the shoreline shows the decrease in water level in the first few years of the 21st century.
6 Lakes That Are Drying Up
illustration of the walking titanosaurus, Patagotitan mayorum
Titanosaurs: 8 of the World's Biggest Dinosaurs

primary clarifier

sanitation engineering

Learn about this topic in these articles:

sewage treatment facilities

  • How is sewage transformed into drinkable water?
    In wastewater treatment: Primary treatment

    These tanks, also called primary clarifiers, provide about two hours of detention time for gravity settling to take place. As the sewage flows through them slowly, the solids gradually sink to the bottom. The settled solids—known as raw or primary sludge—are moved along the tank bottom by mechanical scrapers.…

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