64: Waste Disposal Flashcards
What are the 4 ways to dispose solid waste?
- dumping it
- burying it
- burning it
- composting it
What is composting?
turning organic waste into mulch or humus
Where are open dumps common?
in less developed countries
Are open dumps banned in more developed countries?
yes, but there is still lots of illegal dumping
What occurs in open dumps in less developed countries?
they are full of rodents and people that go through the garbage trying to find something valuable to resell
What do people do illegally in more developed countries?
200 million liters of wasted motor oil poured into sewers or dumped on ground every year
What is happening to the ocean?
ocean dumping
What is ocean dumping?
when people go to the middle of the ocean and dump their garbage there
- ocean is a giant dump for chemical weapons
What is happening to the chemical weapons that have been dumped in the ocean?
old weapons are starting to corrode, toxic chemicals and gases will escape
How much waste do sanitary landfills receive?
57% of waste
What do sanitary landfills contain?
clay and plastic at bottom to prevent leaching
- makes them impermeable to water
- protects groundwater
What is leaching?
water infiltrating and bringing down bad things with it
What is done to waste in sanitary landfills?
waste is covered everyday with soil (fewer rats, less odor, less fires)
What needs to be done before building a sanitary landfill?
geological studies should be done to make sure the site is not permeable or unstable
What happens to tipping fees?
they go up with the land cost
What are the components of a sanitary landfill?
- aquifer: area underground where there is water, many people depend on this for drinking
- plastic liner: makes landfill impermeable
- soil: dumped on top of solid waste, produces methane due to decomposition
- methane gas recovery well: methane is collected, otherwise it could explode
- groundwater monitoring well: samples of aquifer water are taken to check if leaching has occurred
- leachate treatment system: leachate is collected and processed here
What are the disadvantages of sanitary landfills?
- releases greenhouse gases
- methane causes danger of explosion (could be used for energy)
- surface water + groundwater contamination due to leacheate (garbage juice)
- biodegradable and photodegradable plastics not degraded in landfills
- discourages waste reduction and recycling
What is an advantage of a sanitary landfill?
once a landfill is filled, it can be used for something else
ex: Fresh Kills Park
What is Fresh Kills Park?
it was once fresh kills landfill (largest in the world) and it closed, New York transformed it into a park for recreation and a wetland that absorbs water (green park that generates oxygen)
What is incineration?
burning up the waste
What are the benefits of incineration?
- reduces waste volume up to 90% (less need for land)
- produce heat (energy). 1100 waste-to-energy incinerators in the world. They produce less CO2 emissions than oil
- as we burn the waste, that waste becomes fuel to generate heat to vaporize water that moves a turbine to create electricity
What are the problems with incineration?
- it generates air pollution: CO2, particles, heavy metals
- it produces ash that needs to be buried, the ash may contain toxins like dioxins and lead
- there should be enough garbage to fulfill contracts
- expensive to build
- waste to energy incinerators are not functional unless they have a high amount of waste to burn (encourage production of waste)
