In this module, we have seen that landfills and incinerators are the two ways to dispose of material not diverted from the waste stream. Landfills are designed to keep MSW dry and isolated so that the material in the landfill does not contaminate the surrounding environment. Leachate can contaminate nearby land and waterways if it escapes. Anaerobic decomposition in landfills can lead to the formation of methane, a potent greenhouse gas. Incinerators can generate a variety of air pollutants. Any metals contained within MSW that is incinerated may be released into the air. Bottom ash is particulate matter that accumulates underneath the combustion furnace. Sometimes, ash from incinerators can be considered toxic and must be removed using special precautions. Hazardous waste is the subject of our next module.
Module 53 AP® Review Questions
1. Which material, when placed in a landfill, is most likely to cause problems as a result of leaching?
Plastic
Paper
Food matter
Glass
Aluminum
2. A 500 m2 landfill experiences 150 mm of rain each year and 60 percent of the rain is runoff. If the landfill has a 90 percent effective leachate collection system, how much leachate escapes each year?
3 m3
5 m3
16 m3
27 m3
41 m3
3. Incineration of waste is primarily used
to generate heat or electricity.
to reduce waste volume and mass.
to eliminate heavy metals.
when there is no other option.
if the waste is mostly organic material.
4. NIMBY describes
the fact that materials cannot be easily incinerated.
the costs associated with the use of incinerators.
factors contributing to leaching from landfills.
attempts to develop better landfills.
an attitude about the placement of landfills.
5. Which is NOT a detriment of waste incineration compared with landfills?
Increased toxicity of waste
Increased cost to dispose of waste
Increased space taken up by solid waste
Increased air pollution
Decreased incentive to recycle