The life cycle and stream that trash values varies widely based on what the trash or waste is, alongside with where the user initially places the trash. The final destination for waste can be material recovery centers (MRF) aka recycling centers, landfills, compost bins, incinerators, and other places as well including less ideal spots like the ocean or rivers.
Landfills
This is where the majority of trash in the US ends up and is something that most people are familiar with. Trash is taken from homes and businesses with the use of dump trucks where it is compacted one and again sent to a facility to be compacted again before being taken to a Landfill. The waste and/or recyclables that make it to the landfill will stay in the landfill indefinitely and due to anaerobic decomposition the process is slow.
Material Recovery Facility
Material Recovery Facility is what people commonly think of as recycling centers. This is where recyclables are sorted if they come in as a single stream, and baled into their respective material type. Plastics get refined based off of plastics mentioned in Recycling in the USA section of the websites while paper gets sorted based off of it quality. The resulting bales get sent to refinement facilities where the raw materials get turned into pure substances that can be used for manufacturing new goods. This process can be seen outlines in Recycling in the USA section of the website. Oftentimes there is thermosetting plastic that cannot be remelted and recycled so it will oftentimes end up in either landfill discussed above or incinerators discussed later in the page. [1]
Dirty Material Recovery Facility
Is some communities the normal waste is first sent through a dirty material recovery facility. The waste is parsed through for recyclables that are removed from the stream while the rest gets sent to the landfill.
Composting
There are some programs in cities that will take food waste and compost it for agricultural use. This is done by collecting food scraps, oftentimes from public places like museums, blending down the waste and spreading it over pipes that can aerate the waste as seen in the picture below.
Figure 1: Picture of how the compost is spread out. [2]
This makes it so the bacteria can quickly decompose the waste, as apposed to landfills which are anaerobic so the breaking down process is very slow. The final product is fertilizer that can be used in agriculture.
Incineration (Waste to Energy)
Incineration is the commonly known name, but those in industry call it waste to energy due to the negative connotation of waste to energy. The waste is burned at 1800-2200 degrees F while simultaneously heating steam providing energy while the waste gas is scrubbed to eliminate as many toxins as possible.[2]
Other
Reusing – There are many examples a reusing products and it would be difficult to list them all her. This is often seen as the best for the environment as there is no need to use energy to transport the waste or turn the waste into something else usable. [3]
Litter – This category really represents all the waste, especially plastic, glass, and metals that end up in the environment that will not eventually decompose. This can oftentimes affect wildlife as animals can end up accidentally ingesting or having their habitats destroyed by litter. [4]
Sources:
[1] Alexander, G. (2020). How Commercial Composting Works | Earth911.com. [online] Earth911.com. Available at: https://earth911.com/business-policy/how-commercial-composting-works/ [Accessed 18 Feb. 2020].
[2] Sciencing.com. (2020). [online] Available at: https://sciencing.com/effects-littering-environment-animals-8634413.html [Accessed 18 Feb. 2020].
[3] US EPA. (2020). Reducing and Reusing Basics | US EPA. [online] Available at: https://www.epa.gov/recycle/reducing-and-reusing-basics [Accessed 18 Feb. 2020].
[4] AZoM.com. (2020). Understanding Plastics and Polymers – The Different Types of Plastic. [online] Available at: https://www.azom.com/article.aspx?ArticleID=17477 [Accessed 18 Feb. 2020].