CPWM Sustainable Waste Management and Resource Recovery 3 — Questions and Answers
Question 1: Which type of composting system is best suited for processing large volumes of food waste with minimum land requirements?
- Windrow composting
- In-vessel composting (Correct answer)
- Aerated static pile
- Vermicomposting
Correct answer: In-vessel composting
In-vessel composting encloses the process in a drum, tunnel, or container, enabling high throughput with a small footprint and controlled conditions.
Question 2: When evaluating end markets for recovered plastics, which factor most directly affects market stability?
- The color of collected containers
- Commodity price volatility and contamination levels (Correct answer)
- The frequency of collection routes
- Bin size provided to residents
Correct answer: Commodity price volatility and contamination levels
Commodity price swings and high contamination rates are the leading causes of market instability for recovered plastics.
Question 3: A 'zero waste' strategy prioritizes which hierarchy order?
- Disposal, treatment, reuse, reduction
- Reduce, reuse, recycle, recover, dispose (Correct answer)
- Incinerate, landfill, compost, recycle
- Collect, sort, process, market
Correct answer: Reduce, reuse, recycle, recover, dispose
Zero waste strategies follow the EPA waste hierarchy: reduce first, then reuse, recycle, recover energy, and dispose last.
Question 4: What does the term 'upcycling' mean in a resource recovery context?
- Converting waste into a product of higher value or quality than the original (Correct answer)
- Sending waste to a higher-tier landfill
- Increasing the recycling rate by 10% annually
- Transporting recyclables to upstream processing facilities
Correct answer: Converting waste into a product of higher value or quality than the original
Upcycling transforms discarded materials into new products of greater value, improving on the original material's quality or function.
Question 5: Which parameter is most critical when designing a biogas capture system at an anaerobic digestion facility?
- Ambient temperature at the gate
- Hydraulic retention time and organic loading rate (Correct answer)
- Number of trucks delivering feedstock
- Color of the feedstock
Correct answer: Hydraulic retention time and organic loading rate
Hydraulic retention time and organic loading rate govern microbial activity and biogas yield in anaerobic digestion.
Question 6: A municipality wants to reduce textile waste going to landfill. The most sustainable first step is to:
- Incinerate all unsorted textiles for energy recovery
- Establish reuse and repair programs before recycling infrastructure (Correct answer)
- Ban all synthetic fabrics within city limits
- Export collected textiles to developing countries unconditionally
Correct answer: Establish reuse and repair programs before recycling infrastructure
The waste hierarchy places reuse above recycling; establishing repair and reuse outlets maximizes resource value before processing.
Question 7: The concept of 'material flow analysis' (MFA) is used primarily to:
- Optimize truck routing for waste collection
- Track and quantify the movement of materials through a system or economy (Correct answer)
- Calculate landfill airspace consumption
- Audit employee productivity at a MRF
Correct answer: Track and quantify the movement of materials through a system or economy
MFA maps and quantifies inputs, outputs, and stocks of materials within a defined system to inform resource management decisions.
CPWM Sustainable Waste Management and Resource Recovery 3
Which type of composting system is best suited for processing large volumes of food waste with minimum land requirements?