Question

04. Septic tank is:
i) An aerobic attached growth treatment system
ii) An aerobic suspended growth biological treatment system
iii) An anaerobic attached growth biological treatment system
iv) An anaerobic suspended growth treatment system​

Answer 1

Explanation:

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Answer 2

(iii) is the correct option.

A septic tank is an anaerobic attached growth biological treatment system.

• Septic tanks are the earliest known methods for the treatment of wastewater. They have been used from ancient times in the villages of India.
• These are designed in a way to hold wastewater under anaerobic conditions with low velocity for two days.
• The heavy particles in the wastewater settle down and over time they decompose anaerobically and are washed away as effluent.
• While all the light-weighted waste floats to the top and is called the scum.