Question

Aeration tanks have been designed for:

• A. purification of the product
• B. addition of preservatives to the product
• C. ensuring anaerobic conditions in the culture vessel
• D. availability of oxygen throughout the process

Answer 1

The correct option is D

availability of oxygen throughout the process

Aeration tank the tank in which air (or oxygen) is injected in the mixed liquor or sewage effluent. Settling tank is a type of aeration tank where sewage water is collected and allowed to settle its sediment (usually referred to as "final clarifier" or "secondary settling tank") to allow the biological flocs (the blanket of aerobic microbes) to settle, thus separating the biological sludge from the clear treated water. Purification and addition of preservatives to commercial products takes place in specialised containers called fermenters where anaerobic environment is maintained for the anaerobic microbes to ferment and release the desired product.