Question

Measuring Biological Oxygen demand (BOD) is a method used for ______________
A) estimating amount of oxygen in sewage water
B) estimating the amount of organic matter in sewage water
C) Both A & B
D) none of these.

Answer 1

Hint: In this question, we have to compare the options with the question needed to analyse the purpose of measuring BOD. The amount of oxygen taken from the water by bacteria when they oxidise organic materials is measured in milligrammes per litre (mg/L) or parts per million (ppm). When organic stuff is available for food and oxygen is accessible for oxidation, bacteria in water live and reproduce.

Complete answer:
Biological oxygen demand, or BOD, is a chemical procedure for determining the quantity of dissolved oxygen needed by aerobic biological organisms during a body of water to interrupt down organic material present during a given water sample at a particular temperature over a selected period of time.

Let us evaluate the options:
Option A) - This option is correct because the biological oxygen demand is a method used for estimating the amount of oxygen present in the sewage water. The river is considered highly polluted if it contains
BOD values are higher than 8 mg/L

Option B) - This is also the correct option since it involves estimating the amount of organic matter in sewage water. Plant and animal remains are used to make organic matter. As a result, it's used to figure out how much organic matter is in a given volume of water.

Option C) - Both are correct because The effect of organic matter on the concentration of dissolved oxygen in a stream or lake is critical to water-quality management. The amount of oxygen required to remove waste organic matter is measured by BOD. The waste organic matter is stabilised or rendered unobjectionable through decomposition by living bacterial organisms that require oxygen to function.

Option D) - None of these is the wrong answer. Because option C is the right one.

Thus, the correct answer is Option ‘C’.

Because The amount of dissolved oxygen required (required) by aerobic biological organisms to break down organic material present in a given water sample at a given temperature over a given time period is referred to as biological oxygen demand (BOD).

If there is a large amount of organic material in a water supply, BOD levels will be high because there will be a large number of bacteria present to dissolve the waste. Treatment will then be used to reduce the amount of organic waste before it is discharged into receiving water.

Note:
- It is important to note that temperature, pH, the presence of certain microbes, and the type of organic and inorganic material in the water all have an impact on the rate of oxygen consumption.
- You need to know that there is a certain amount of dissolved oxygen present in water, that is essential for its organism.
- Higher BOD indicates there is a high demand for oxygen to remove waste organic matter, lower the water quality.
- Low oxygen demand means there is less requirement of oxygen and maintains quality.