A. treatment of sewage
B. treatment of water
C. purification of chemicals
D. purification of metals
Correct Answer:
Option A – treatment of sewage
Explanation
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.