CES Pollution Control & Waste Management 2 — Questions and Answers
Question 1: Under the Clean Air Act, which pollutant is classified as a 'criteria pollutant' and has a National Ambient Air Quality Standard (NAAQS)?
- Benzene
- Lead (Correct answer)
- Dioxin
- Polychlorinated biphenyls (PCBs)
Correct answer: Lead
Lead is one of six criteria pollutants regulated under NAAQS, along with ozone, particulate matter, CO, SO2, and NO2.
Question 2: Which wastewater treatment process uses microorganisms attached to a rotating disk to biologically degrade organic matter?
- Activated sludge
- Rotating biological contactor (RBC) (Correct answer)
- Trickling filter
- Sequencing batch reactor
Correct answer: Rotating biological contactor (RBC)
A rotating biological contactor uses biofilm on rotating discs partially submerged in wastewater to treat organic pollutants.
Question 3: What is the primary regulatory framework governing the cleanup of contaminated brownfield sites in the United States?
- RCRA
- CERCLA (Superfund) (Correct answer)
- TSCA
- CWA Section 404
Correct answer: CERCLA (Superfund)
CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act) establishes the Superfund program for remediating hazardous waste sites.
Question 4: Which air pollution control device uses electrical charges to remove particulate matter from industrial exhaust streams?
- Cyclone separator
- Bag filter (fabric filter)
- Electrostatic precipitator (ESP) (Correct answer)
- Wet scrubber
Correct answer: Electrostatic precipitator (ESP)
Electrostatic precipitators charge particles and collect them on oppositely charged plates, achieving very high efficiency for fine particulates.
Question 5: In a municipal solid waste landfill, what is the purpose of a leachate collection system?
- To capture landfill gas for energy recovery
- To prevent groundwater contamination by collecting liquid that percolates through waste (Correct answer)
- To control odors from decomposing waste
- To monitor methane concentrations in the vadose zone
Correct answer: To prevent groundwater contamination by collecting liquid that percolates through waste
Leachate collection systems capture contaminated liquid draining through landfill waste to prevent it from reaching groundwater.
Question 6: Under RCRA, which characteristic makes a waste 'hazardous' due to its ability to cause severe corrosion of steel containers?
- Ignitability
- Reactivity
- Toxicity (TCLP)
- Corrosivity (Correct answer)
Correct answer: Corrosivity
Corrosivity is defined as a pH ≤2 or ≥12.5, or a liquid that corrodes steel at a rate >6.35 mm/year.
Question 7: Which technique is commonly used to remediate volatile organic compound (VOC) contamination in groundwater by injecting air below the water table?
- Soil vapor extraction
- Air sparging (Correct answer)
- Pump and treat
- Permeable reactive barrier
Correct answer: Air sparging
Air sparging injects air below the water table to volatilize dissolved VOCs, which are then captured by a soil vapor extraction system above.
CES Pollution Control & Waste Management 2
Under the Clean Air Act, which pollutant is classified as a 'criteria pollutant' and has a National Ambient Air Quality Standard (NAAQS)?