Environmental Engineering quiz

More questions about Environmental Engineering

These visible examples show the question style. LearnClash turns the full topic into ranked duels and spaced repetition.

1. 1 Easy

   Which gas from burning coal helps form acid rain?

   Answer: Sulfur dioxide

   Why: Flue-gas desulfurization systems, or scrubbers, were developed to trap sulfur dioxide before it leaves smokestacks.

2. 2 Medium

   What is the slimy, biologically active layer atop a slow sand filter called?

   Answer: schmutzdecke

   Why: The purifying film forms within 10 to 20 days of start-up, and when it clogs, workers scrape off the top few millimetres of sand.

3. 3 Hard

   What toxic byproducts form when chlorine reacts with organic matter?

   Answer: Trihalomethanes

   Why: Johannes Rook traced them to chlorine attacking humic matter in 1974; the EPA now caps total trihalomethanes at 80 parts per billion.

4. 4 Easy

   Which two minerals primarily cause hardness in drinking water?

   Answer: Calcium and magnesium

   Why: Water turns hard as it seeps through limestone, chalk or gypsum, and boiling can precipitate part of that hardness as calcium carbonate scale.

5. 5 Medium

   Which nutrient usually limits eutrophication in coastal waters?

   Answer: Nitrogen

   Why: Phosphorus usually limits algae in freshwater lakes, but in many coastal waters nitrogen is the nutrient that limits them.

6. 6 Hard

   What biological process does a trickling filter use for wastewater?

   Answer: Attached growth

   Why: The biofilm on the media keeps thickening until it sloughs off in patches, so a settling tank downstream catches the shed biomass.