What is the importance of dissolved oxygen in water? How does oxygen reach water?

What processes are generally responsible for the deoxygenation of water?

Mention different measures for controlling water pollution. 

Describe quality parameters and standards for drinking water.

What is soil pollution? How does it differ from air and water pollution?

What are the different sources of soil pollution? Discuss various measures for controlling soil pollution.

Explain giving reactions, the plausible explanation for the escape of methyl isocyanate gas from the Union Carbide Ltd. Plant in Bhopal on Dec 2, 1984.

How can domestic waste be used as manure?

For your agricultural field or garden, you have developed a compost producing pit. Discuss the process in the light of bad odour, files and recycling of wastes for a good produce.

What are pesticides and herbicides? Explain giving examples.