Biotechnology is applied in the? 

A.

treatment of sewage

B.

treatment of water

C.

purification of chemicals

D.

purification of metals

Correct answer is A

There are several wastewater treatment methods based on biotechnology that are used worldwide. It includes Activated Sludge, Oxidation Ponds, Tricking Filters, Bio-filters and Anaerobic treatment. All the methods are part of the biological wastewater treatment and use microbes to treat organic waste in sewage.