Basic Wastewater Operator Practice Exam

Hydrogen sulfide gives off an odor similar to what?

1. Peanut butter

2. Rotten eggs

3. Rotten apples

4. Dirt

The correct answer is: Rotten eggs

Hydrogen sulfide is a gas recognized by its distinctive and pungent odor, which is often described as smelling similar to rotten eggs. This characteristic odor is primarily due to the presence of sulfur in hydrogen sulfide. When organic materials decompose anaerobically (without oxygen), hydrogen sulfide is typically produced as a byproduct, which explains its common association with sewage and wastewater environments. Understanding this odor is crucial for wastewater operators, as it can serve as an early warning sign for the presence of hydrogen sulfide in wastewater treatment facilities. Recognizing and managing this gas is important for both safety and compliance with health regulations, as exposure to high concentrations can pose health risks. In contrast, the other options provided do not accurately represent the odor of hydrogen sulfide. Peanut butter has a sweet, nutty smell; rotten apples might emit a more fruity, foul scent; and dirt has a very earthy aroma. None capture the specific and distinct smell of rotten eggs that hydrogen sulfide is known for.