QUESTION
Objective Question
From amongst the following sewage treatment options, largest land requirements for a given discharge will be needed for
Answer
( Option D)
oxidation pond.
Solution
An oxidation pond (also known as a waste stabilization pond) is a completely natural, low-rate biological treatment
system. Because it is designed very shallow (typically 1 to 1.5 metres deep) to allow full sunlight penetration and relies
entirely on natural atmospheric oxygen transfer and algal-bacterial symbiosis rather than mechanical aeration, it requires
a very low organic loading rate.
Consequently, it demands a massive surface area and extensive hydraulic retention times (often spanning 10 to 20 days)
to treat a given discharge.
