8.9 Solid Waste Disposal

Municipal Solid Waste (MSW)

solid waste from cities (households, businesses, schools, etc.)

Waste “stream”

a flow of solid waste to recycling centers, landfills, or trash incineration facilities

what makes up the majority of trash composition?

paper (recyclable) followed by food & yard trimmings (organic, which can be composted)

E-Waste

old technology, such as old computers, TVs, phones, tablets, which make up a small portion of MSW but are considered hazardous due to metals and chemicals used in manufacturing

why should old tech be disposed of separately from MSW?

certain chemicals and metals in old tech are considered hazardous --can leach endocrine disrupting chemicals out of landfills so require special procedures

Sanitary Landfills,

where developed nations dispose of trash

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**clay/plastic bottom liner** landfill

clay at bottom of the landfill prevents pollutants from leaching

**leachate collection system** landfill

system of tubes/pipes at bottom collect water draining thru waste (which carries pollutants) for treatment and disposal

**methane recovery system landfill**

system of tubes/pipes collect methane produced by anaerobic decomposition in the landfill, which can be used to generate electricity or heat buildings

clay cap landfill

clay-soil mixture covers a landfill once it’s full, which keeps out animals, keeps in smell, and allows vegetation to regrow

landfill decomposition rates

very low decomposition rates due to low o2, moisture, and organic material combination → landfills typically remain the same size as when they were filled

Landfill Issues include:

groundwater contamination (leaching), release of GHG (CO2 and methane are released during composition of trash, and cause climate change)

waste incineration pros

can reduce volume of landfill waste by 90%, can be used to generate electricity

waste incineration cons

releases CO2 and air pollutants like PM, SOx, and NOx, as well as bottom ash which may contain toxic metals or the leaching of toxic metals themselves

NIMBY (not in my backyard)

communities don’t want landfills near them due to smell & sight, the potential for attracting pests, and groundwater contamination concerns → landfills often placed near low-income or minority communities that don’t have the resources or political power to fight against the decisions