Question

26) The propagation cycle that occurs in acid mine drainage is caused by

A) reduction of Fe3+ by sulfuric acid.
B) the oxidation of sulfide to sulfuric acid by microbial oxidation of iron (Fe3+).
C) microbial sulfate reduction.
D) low pH and high oxygen concentrations.

Answer 1

The propagation cycle in acid mine drainage is caused by the oxidation of sulfide to sulfuric acid by microbial oxidation of iron (Fe3+). This results in a low-pH environment that can harm aquatic life.

Step-by-step explanation:

The propagation cycle that occurs in acid mine drainage is caused by the oxidation of sulfide to sulfuric acid by microbial oxidation of iron (Fe3+).

In the process of mining, when water and oxygen interact with sulfide-oxidizing bacteria, they produce large amounts of sulfuric acid as a byproduct. This results in a low-pH environment that can be harmful to aquatic plants and animals.

For example, in acidic mine drainage, water and acid-loving microorganisms generate acid in rivers, such as Spain's Rio Tinto, which has a pH close to 2. The acid-loving microorganisms thrive in these waters, contributing to the acid generation.