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.

Question

Quizplus · Accepted Answer

Acid mine drainage is caused by the exposure of sulfide minerals, such as pyrite (FeS₂), to oxygen and water, which produces sulfuric acid. Microbial oxidation of Fe(III) is responsible for the regeneration of Fe(II), which can then further oxidize more sulfide minerals, perpetuating the cycle of acid generation.

The Propagation Cycle That Occurs in Acid Mine Drainage Is