Question:

Secondary sewage treatment is mainly a

Show Hint

The microbes function to reduce the waste toxicity tested by measuring the BOD.

Updated On: Sep 12, 2022
  • physical process
  • mechanical process
  • chemical process
  • biological process
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is D

Solution and Explanation

The treatment of sewage is a biological process because it involves the treatment of microorganisms.

  • The microbes function to reduce the waste toxicity tested by measuring the BOD (biological oxygen demand) and COD (chemical oxygen demand) value of the water.
  • The microbes help to treat the sludge that is produced by the wastewater.
  • Therefore, it is called a biological process.

Option A:

A physical includes gradual change through transient states. The treatment of sewage water is not a physical process.

Option B:

No objects interact to generate mechanical energy in secondary sewage treatment.

Option C:

Treatment of sewage is not a chemical process as a change in chemical state or production of different chemicals is not involved.

Therefore Option D is correct - Secondary sewage treatment is mainly a biological process.

Was this answer helpful?
0
0

Concepts Used:

Microbes in Human Welfare

There are several valuable microorganisms that are beneficial to humans in various manners such as:

In Household Products

  1. Fermentation of milk to produce yogurt.
  2. Milk cuddling to compose curd, cheese, and paneer.

In Industrial Products

  1. Production of beverages such as wine, beer, whiskey, brandy, or rum.
  2. Production of antibiotics such as Penicillin and other chemical substances to kill or retard the expansion of disease-causing microbes.

Fermented Beverages

  1. A fermentor is used to produce microbes on a large scale for industrial purposes.
  2. The brewer’s yeast (Saccharomyces cerevisiae) is used to make ethanol. At this time, the yeast ferments malted cereals and fruit juices.

Antibiotics

  1. The term antibiotic means “against life”. These materials can kill or destroy the growth of other microbes.