BE/B Eng Bachelor of Engineering Environmental Engineering 1 — Questions and Answers
Question 1: What is Biochemical Oxygen Demand (BOD) a measure of?
- The amount of oxygen microorganisms need to decompose organic matter in water (Correct answer)
- The concentration of dissolved oxygen in water
- The total nitrogen content of wastewater
- The pH level of industrial effluent
Correct answer: The amount of oxygen microorganisms need to decompose organic matter in water
BOD measures the quantity of oxygen consumed by biological processes breaking down organic material in water at a given temperature over a set time period (typically 5 days at 20°C).
Question 2: Which water treatment process removes suspended solids by allowing them to settle under gravity?
- Sedimentation (Correct answer)
- Coagulation
- Filtration
- Disinfection
Correct answer: Sedimentation
Sedimentation (clarification) allows suspended particles to settle to the bottom of a basin under gravitational force, removing them from the water.
Question 3: What is the primary greenhouse gas produced by human activities contributing to climate change?
- Carbon dioxide (CO₂) (Correct answer)
- Oxygen (O₂)
- Nitrogen (N₂)
- Argon (Ar)
Correct answer: Carbon dioxide (CO₂)
CO₂ from fossil fuel combustion, deforestation, and industrial processes is the dominant anthropogenic greenhouse gas driving global warming.
Question 4: In air pollution control, what does a baghouse filter remove from industrial exhaust?
- Particulate matter (dust and fine particles) (Correct answer)
- Sulfur dioxide gas
- Carbon monoxide
- Volatile organic compounds
Correct answer: Particulate matter (dust and fine particles)
A baghouse uses fabric filter bags to capture particulate matter from industrial exhaust gas streams, achieving high collection efficiencies for fine particles.
Question 5: What is the purpose of a landfill liner in solid waste management?
- To prevent leachate from contaminating underlying soil and groundwater (Correct answer)
- To accelerate decomposition of waste
- To capture methane gas for energy recovery
- To reduce the volume of waste
Correct answer: To prevent leachate from contaminating underlying soil and groundwater
Landfill liners (typically HDPE geomembrane and compacted clay) create an impermeable barrier that prevents toxic leachate from migrating into groundwater.
Question 6: What does the term 'eutrophication' describe in aquatic environments?
- Excessive nutrient enrichment causing algal blooms and oxygen depletion (Correct answer)
- The natural aging and infilling of a water body
- Acidification of a lake due to acid rain
- Saltwater intrusion into freshwater bodies
Correct answer: Excessive nutrient enrichment causing algal blooms and oxygen depletion
Eutrophication occurs when excess nutrients (nitrogen, phosphorus) from agricultural runoff or sewage stimulate excessive algal growth, leading to oxygen depletion and ecosystem damage when algae decompose.
BE/B Eng Bachelor of Engineering Environmental Engineering 1
What is Biochemical Oxygen Demand (BOD) a measure of?