Recycling and Resource Recovery Flashcards

Which material contamination issue most commonly degrades the quality of recovered glass cullet in MRF operations?

Answer: Ceramic and porcelain fragments

Ceramics and porcelain have higher melting points than glass and cause defects in the final product, making them the most damaging contaminant in cullet.

The 'recovered materials' definition under EPA guidelines distinguishes recyclables from solid waste primarily based on:

Answer: Whether the material is legitimately recycled versus speculatively accumulated

EPA uses legitimate recycling criteria to separate true recovered materials from waste, focusing on whether the material is actually used or reused rather than just stored.

In single-stream recycling programs, which statement about contamination rates is most accurate compared to dual-stream programs?

Answer: Single-stream typically yields higher contamination rates but greater participation

Single-stream programs generally increase resident participation but also increase contamination rates because mixed materials are harder to sort and residents are less careful.

What does the term 'closed-loop recycling' mean in resource recovery practice?

Answer: A material being recycled back into the same or equivalent product

Closed-loop recycling means a material like aluminum is recycled back into the same product (new cans), preserving material quality and reducing the need for virgin inputs.

Which federal act primarily governs the regulation of hazardous secondary materials that are recycled?

Answer: Resource Conservation and Recovery Act (RCRA)

RCRA Subtitle C regulates hazardous waste, including hazardous secondary materials destined for recycling, establishing whether they remain subject to hazardous waste rules.

A material recovery facility (MRF) manager notices that recovered fiber bales are being rejected by the paper mill. The most likely cause is:

Answer: Outthrow and prohibited materials exceed contract specifications

Paper mills reject fiber bales when outthrow (non-fiber materials) and prohibited materials exceed the agreed contamination tolerance in the offtake contract.

Which optical sorting technology uses near-infrared (NIR) spectroscopy in MRF operations?

Answer: Polymer sorting systems

NIR spectroscopy identifies polymer types by their unique light absorption signatures, enabling automated sorting of different plastic resins on the conveyor line.