Which of the following factors help to measure quality of water:

Explanation

1. Dissolved Oxygen (DO)In water the most important oxidizing agent is dissolved molecular oxygen (O2) the concentration of which ranges from 4 - 8 ppm. The organic matter is oxidized with the help of this dissolved oxygen in water.It is a parameter to determine the quality of water. 2. Biochemical Oxygen Demand (BOD)It is the capacity of organic matter in natural water to consume oxygen within a period of five days. The value of BOD is the amount of oxygen consumed as a result of biological oxidation of dissolved organic matter in the sample. 3. Chemical Oxygen Demand (COD)The organic content of water which consumes oxygen during chemical oxidation is evaluated by its chemical oxygen demand. The oxygen demand of water can be determined directly by treating it with dichromate ions Cr2O7 2- which is a powerful oxidizing agent.