Question

'Biological Oxygen Demand' (BOD) is a measure of

• A. Industrial wastes poured into water bodies
• B. Extent to which water is polluted with organic compounds
• C. Amount of carbon monoxide inseparably combined with haemoglobin
• D. Amount of oxygen needed by green plants during night

Answer 1

The correct option is B Extent to which water is polluted with organic compounds

Biochemical oxygen demand is a measure of how much dissolved oxygen is being consumed as microbes break down organic matter. A high demand, therefore, can indicate that levels of dissolved oxygen are falling, with potentially dangerous implications for the river's biodiversity. High biochemical oxygen demand can be caused by high levels of organic pollution, caused usually by poorly treated wastewater; high nitrate levels, which trigger high plant growth.