Which of the following problem occurs due to the use of nuclear energy?

For drinking purpose, water should be tested for _______________.<br> </h2></div>

Which sewage contains biodegradable waste such as organic matter?

Which of the following enhances B.O.D. of water ?</h2></div>

In which one of the following, the BOD (Biochemical Oxygen Demand) of sewage (S), distillery …

Elements can be diagonsed by</h2></div>

Sewage water is purified for recycling by the action of:</h2></div>

Which of the following does not affect ozone layer ?</h2></div>