[jan] Water pollution in Gujrat

Question 1

Rank of gurat in states having highest polluted rivers?

Answer 1

ranked fourth among the top five States with highly polluted rivers, with as many as 20 rivers in the critically polluted category.

Question 2

What is chemical oxygen demand (COD) & what is it’s permissible limit?

Answer 2

-indicates organic pollutant load

-If COD is higher than 250 mg per litre, then it should not be released into the rivers.
Most of the Gujarat rivers where the effluents are dumped into, the COD level is in the range of 700 to 1000 mg per litre.

Question 3

What is Dissolved Oxygen (DO) level parameter & what is it’s expected range?

Answer 3

• an indicator of the health of a river in perennial rivers

- should be in the range of 6 to 8 mg per litre, it is actually below 2.9 mg per litre.

Question 4

What is Biological Oxygen Demand? (BOD)

Answer 4

Biological Oxygen Demand is defined as the amount of dissolved oxygen required by aerobic microorganisms to breakdown the organic materials in a sample of water at a specific temperature & timeframe. In simpler words, The amount of oxygen needed by biological organisms such as bacteria in a given water sample for a breakdown of organic matter by oxidation process is called the Biochemical Oxygen Demand.