Solid Waste and Sewage Disposal Flashcards
Where does solid waste come from?
Generated in domestic, industrial, business, and agricultural sectors
What is electronic waste?
e-waste composed of discarded electronic devices including televisions, cell phones, and computers
What are the environmental effects of landfills?
can contaminate groundwater and release harmful gases
What systems are in place at sanitary municipal landfills to reduce the harmful impact?
- lined at the bottom with plastic or clay
- stormwater collection system
- leachate collection system (collected leached water)
- cap (covers the landfill using crushed glass, soil, wood )
- methane collection system
What factors help the decomposition of solid waste?
- ensure that there are microbes (decomposers) present in the landfill to ensure the microbial decomposition of waste
- ensure pH is as acidic as possible to help break down the waste
How do incinerators work? What are their benefits/harms? What waste does it still produce?
Solid waste is disposed at incineration and burned
- it significantly reduces the amount of solid waste but increases air pollutants
- produces wastewater (sewage treatment) and ash (still has to be disposed of landfills)
How are environmental problems caused by the illegal disposal of materials that are not accepted at landfills (ex: rubber tires)?
- used rubber tires, when left in piles can become breeding grounds for mosquitoes that can spread disease
What are the effects of countries putting their waste in the ocean?
- large floating islands of trash in oceans
- wildlife can become entangled in or ingest waste
- waste can also fall while it is transported and runoff into water sources`
How does the used water travel to its final location?
- down the drain or toilet
- series of sewage pipes
- mixes with all the other wastewater in your community
- wastewater treatment plant
Where are water treatment facilities usually located?
- close to bays, rivers, etc. (moving bodies of water, usually NOT small lakes)
What is the purpose of wastewater treatment facilities?
- filtered and treated enough to return to water sources
How do wastewater treatment places deal with the biodegradable materials in wastewater? What are some examples of these biodegradable materials?
- wastewater treatment facilities will host microbes that can break down living organisms
- soap, animal/plant waste, paper
What are the steps of primary sewage treatment?
- Filtration - wastewater passes through a large screen to remove solid objects
- First Settling Tank - wastewater is sent into a large tank, smaller particles sink to the bottom and form sewer sludge, sludge is removed from water
- Sludge is brought to a drying place (usually at the same facility)
What are the steps of sewage secondary treatment?
- Wastewater is sent to a large tank, where any remaining sludge is removed from the water
- Aeration Tank - Wastewater is mixed with oxygen and bacteria, bacteria use the oxygen and feeds on waste (pump in more dissolved oxygen because it is needed for the bacteria to feed on waste)
- Chlorination: Chlorine is added to disinfect the water before it is released back (can also use ozone or UV light)
Tertiary treatment
- use of ecological or chemical processes to remove any pollutants left in the water after primary or secondary treatment
What is sewage sludge? How is it dealt with when it is hazardous?
- a product of wastewater treatment, solid material that remains after treatment
- sludge can contain dangerous concentrations of toxic chemicals and must be disposed of as hazardous waste, usually brought to incinerators
How have communities been recycling the sludge if the sludge is determined to be at a non-toxic level?
- used as fertilizer
- combined with clay to make bricks that can be used in buildings
How can we reduce the amount of generated waste?
- Reduce
- Reuse
- Recycle
What is recycling and why is not the most advantageous method of reducing waste?
- Process by which certain solid waste materials are processed and converted into new products
- One way to reduce current global demand on minerals, but this process is energy-intensive and can be costly
Why does most recycling end up in landfills?
- Used to be underdeveloped countries that took recycling and turned it into raw materials, now they don’t take it anymore because there’s too much unprocessed recycling in these countries
What is composting? What are the drawbacks?
- the process of organic matter such as food scraps, water, and yard waste decomposing, used for fertilizers
- odor and rodents
What are the issues with E-waste?
- contains heavy metals like lead and mercury, can lead to leaching from landfills into groundwater if not disposed of properly
What are landfill mitigation strategies?
- burning waste for energy
- restoring habitat on former landfills used for parks
What are water treatment facilities not designed to treat?
Not designed to treat pharmaceuticals and other toxic compounds from the water (how endocrine disruptors get into the water sources)
What substances are used in tertiary treatment to remove pollutants from the water?
- chlorine, UV radiation, ozone