<i>Azolla </i>is used as a biofertilizer because <br> </h2></div>

Secondary treatment is also known as ________________.<span><br> </span></h2></div>

Choose the correct answers from the alternatives given.<br> A free-living bacterium capable of fixing nit…

Which one of the following is associated with denitrification?</h2></div>

What is the full form of BOD?

Which one of the following pairs is correctly matched?</h2></div>

Which of the following plant is used as green manure?</h2></div>

Who discovered the first antibiotic?</h2></div>