Waste Item

Waste Type *

Time to degrade or decompose

Further Explanation References

Aluminum Can Recycling

* > 1 million years

Aluminum is extremely chemically stable* and

rarely oxidizes* to degrade.* Aluminum foil is NOT recyclable in Toronto because of waste processing limitations and commonly being contaminated with food.

www.kabc.wa.gov.au/library/file/Fact%20sheets/How%20long%20Fact%20sheet%20KAB.pdf www.scifun.org/CHEMWEEK/Aluminum2017.pdf

Apple Core

Organic

*

2 - 6 months

The exposed apple flesh in addition to high

water and sugar content allows for quick

decomposition* by microbes.

www.des.nh.gov/organization/divisions/water/wmb/coastal/trash/documents/marine_debris.pdf

Banana Peel/ Orange Peel

Organic *

1 month - 2 years

Complex carbohydrate structures (cellulose) in skins/peels resist breakdown by microbes (biodegradation*). Decomposition* is slow due to low water and sugar content.

www.engineering.mit.edu/engage/ask-an-engineer/what-makes-wood-rot-so-slowly/

Batteries

Specialized

Recovery *

100 - 1 million years

Made from various metals, metal oxides and plastics that vary in their ability to degrade.* Outer casing often corrodes first, releasing

potentially harmful contents.

www.nema.org/Policy/Environmental-Stewardship/Documents/NEMABatteryBrochure2.pdf

Chip Bag Landfill

* >1 million years

Made of layers of PP* and aluminum foil which cannot be separated in the recycling process.

Both materials are very resistant to degradation.*

www.npr.org/sections/thesalt/2014/07/24/334617901/the-weird-underappreciated-world-of-plastic-packaging

Cling Wrap Landfill

*

> 450 years

Made of LDPE*, PVC*, or PVDC* which are all chemically stable* and therefore resistant to oxidation* and other forms of chemical break down (degradation*).

www.npr.org/sections/thesalt/2014/07/24/334617901/the-weird-underappreciated-world-of-plastic-packaging

Disposable Coffee Cup

Landfill *

2 months -20 years

Paper treated to produce disposable cups limits oxidation* capacity of fibres (lignin*) causing them to decompose very slowly. Cups are also

lined with LDPE* which resists degradation.* These cups are NOT recyclable in Toronto.

www.engineering.mit.edu/engage/ask-an-engineer/what-makes-wood-rot-so-slowly/

Electronics (e.g., Cell Phones)

Specialized

Recovery *

> 1 million years

Made from special glass-ceramics, thermoplastics (e.g., polycarbonate), and metals (including rare earth metals and ores (coltan)), which are all very chemically stable* and do not degrade.*

www.acs.org/content/acs/en/education/resources/highschool/chemmatters/past-issues/archive-2014-2015/smartphones.html www.plastics.americanchemistry.com/Ten-Facts-About-Plastics-from-Electronics/

Glass Jar Recycling

* > 1 million years

Made of melted sand (mostly silica) which is extremely chemically stable.* Under ideal conditions and if not recycled, glass will break into smaller and smaller pieces and usually enter the rock cycle.

www.quora.com/Geology-What-are-the-most-abundant-minerals-on-Earths-crust

Ink Cartridges

Specialized

Recovery *

450 years - > 1000 years

Ink can be made of vegetable or seed oils, pigments suspended in solution, plastics, metals or metal oxides that vary in their ability to degrade (e.g., biodegradable* to resistant to degradation*). The cartridge, made of various

hard plastics, resists degradation.

www.pubs.acs.org/cen/whatstuff/stuff/7646scit2.html www.preton.com/GreenPrinting.asp

Juice Bag

(e.g., Kool Aid Jammers)

Landfill

* > 1 million years

Layers of aluminum foil, anti-oxidation materials and different plastics are laminated together. These materials are all extremely resistant to

degradation.*

www.standuppouches.net/blog/what-materials-are-juice-pouches-made-of

Juice Box

Recycling

* 5 - 300 years

Made of layers of paperboard, different plastics

and aluminum foil. Paperboard degrades* but plastics and aluminum take much longer.

www.madehow.com/Volume-7/Juice-Box.html

Waste Timeline:

Decomposition* and degradation* times for all waste varies depending on the environment;

exposure to oxygen, water, air, acids, bases, temperature and living organisms will all affect the time.

Waste Item

Waste Type *

Time to degrade or decompose

Further Explanation References

Milk Carton Recycling

* 5 years

Made from paperboard coated with LDPE.* Paperboard fibres still contain traces of lignin* which allows oxidation* to occur. LDPE causes

the degradation* time to be longer.

www.madehow.com/Volume-4/Milk-Carton.html

Paper Towel Organic

* 2 - 4 weeks

Unbleached paper fibres (lignin*) are extremely short, easily pulled apart and susceptible to oxidation.*

www.engineering.mit.edu/engage/ask-an-engineer/what-makes-wood-rot-so-slowly/

Plastic Bag

Recycling *

1 year - 1 million years

Made from petrochemical products* (HDPE*/LDPE*) which never truly degrade.* They may be broken down by the sun (photo-

degradation*). Plastics may degrade* into BPA (Bisphenol A) a hormone blocker.

www.science.howstuffworks.com/science-vs-myth/everyday-myths/how-long-does-it-take-for-plastics-to-biodegrade.htm

Plastic Water Bottles, Fruit Cups, and Utensils

Recycling *

450 years

Made of PET(E).* Of all petrochemical

products* PET degrades most easily and is the most commonly recycled. BLACK plastic is NOT

recyclable in Toronto due to processing limitations.

www.dolecrs.com/sustainability/packaging/

www.britannica.com/science/polyethylene-terephthalate

Polypropylene Straws

Landfill *

200 - 450 years

PP* is chemically resistant to many acids and bases, it can be oxidised* by certain acids and can be broken down by the sun (photo-

degradation*). The large surface area of a straw offers more opportunity for degradation.

www.madehow.com/Volume-4/Drinking-Straw.html www.bpf.co.uk/plastipedia/poly

mers/PP.aspx www.britannica.com/science/polypropylene

Polystyrene Foam Bowl

(e.g., Styrofoam Container,

Yogurt Cups)

Recycling

* 500 - > 1 million

years

PS* is extremely chemically stable* and inert.* It is resistant to acids and bases. Only

Methanogenic consortia bacteria and mealworms are able to biodegrade* the product. It is usually stabilized against degradation as it naturally photo-degrades.*

www.ceaa-acee.gc.ca/050/documents/56647/56647E.pdf www.earthresource.org/campaigns/capp/capp-styrofoam.html

Popsicle Stick

Landfill

* 2 - 5 years

Wood fibre structure (cellulose* and lignin*) resists microbes. This, combined with low water and sugar content, cause slow decomposition*/biodegradation.*

www.engineering.mit.edu/engage/ask-an-engineer/what-makes-wood-rot-so-slowly/

Soiled Paper

Recycling /

Organic *

5 - >20 years

Paper is typically bleached, processed and acid-free. This process removes part of the wood fibres (lignin*) leaving the complex carbohydrate cellulose* behind. Cellulose resists biodegradation* and oxidation.* Soiled paper (with food waste) goes into the

organic bin.

www.engineering.mit.edu/engage/ask-an-engineer/what-makes-wood-rot-so-slowly/

www.fopap.org/fx_paper_landfill.doc

Tea Bags

Organic / Landfill

*

2 - 6 months or 30 - 40 years for

Nylon

The low levels of plastic (PP* / LDPE*)

combined with paper fibres slows down the

decomposition*/ degradation* processes. Tea ingredients decompose quickly relative to the tea bag. Nylon and Silk bags can take up to 40 years to break down and must be sent to landfill.

www.recyclethis.co.uk/2011060

2/composting-teabags

PET(E)-Polyethylene

terephthalate: The most commonly recycled plastic. Also degrades the most quickly as it is susceptible to photo-degradation and oxidation.

HDPE- High-density polyethylene:

HDPE has a stronger chemical structure than LDPE although they are both made of Polyethylene. This chemical structure causes it to withstand degradation.

PVC-Polyvinyl chloride:

Is chemically stable and resistant to oxidation and other forms of chemical break down. Only 6 species of fungus have been found to effectively biodegrade the material.

LDPE-Low-density polyethylene:

Chemical structure causes it to be resistant to degradation.

PP-Polypropylene: Is resistant to many acids and bases, it can be easily oxidised by certain acids and can be photo-degraded. Because of its naturally susceptible oxidation capacity PP is often combined with anti-oxidants. It is biodegraded by microbes when mixed with starch.

PS-Polystyrene: Is extremely chemically stable and inert. It is resistant to acids and bases. Only Methanogenic consortia bacteria and mealworms are able to biodegrade polystyrene.

Other: (e.g., PVDC-

Polyvinylidene chloride)

Other plastics or mixes of plastics are caught in this catch-all resin identification code.

Biodegrad(e/ation) The bio-chemical process of break-down into constituents by microbes.

These constituents are naturally occurring.

Cellulose A complex chain of several hundred to thousands of carbohydrates. It is an important structural component of cell walls. It is one of the most abundant chains of carbohydrates in the world; therefore its chemical structure is incredibly stable and strong. This is why ruminants (e.g., cows) have so many stomachs full of symbiotic bacteria to help them digest it.

Chemical(ly) stable/ Stability

The molecules/elements are in their lowest energy state. Essentially they are comfortable in the position they’re in, for example, not searching to lose or gain electrons.

Decompos(e/ition) The organic (naturally occurring) process of breaking organic matter down into its constituent parts. (e.g., composting)

Degrad(e/ation) The deleterious change in the chemical structure, physical properties or appearance of a material from natural or artificial exposure. (e.g., photo-degradation, oxidation, wind, cold, heat)

Inert Chemically unreactive, a tendency to remain unchanged.

Lignin Fills the space in the cell walls, between cellulose and other components. It is found in wood, and is one of the most slowly decomposing components of dead vegetation (becomes a large fraction of humus). Lignin can be oxidised and biodegraded (e.g., yellowing of newspaper/rotting of dead trees).

Oxid(ize/ation) Gaining an oxygen molecule or losing electrons, usually achieving a more stable chemical state/structure.

Petrochemical

Products Common plastics are made of petroleum derivatives. Petroleum is a fossil fuel.

Photodegrad(e/ation) The process of being degraded by the sun (UV rays/visible light) where chains of molecules can be broken apart by photo-oxidation. This leads to deterioration of mechanical properties and creates useless materials. This occurs in polystyrene if it is not stabilized to protect its degradation.

Glossary:

Toronto’s Waste Processes

Blue Bin:

The Solid Waste Management Services at Dufferin Transfer station do not refine or melt any of the products

but sells them; prices offset costs for running the program.

Green Bin:

Toronto sends organics to Disco Road and Dufferin Organics Processing Stations for anaerobic (oxygen

deprived) processing. Anaerobic processing allows us to capture methane (a GHG and potential energy

source), waste water and prevent odour. Afterwards the partially decomposed pulp is sent for aerobic

decomposition.

1. People pull out

unwanted items.

2. The rest go to disk screens which sort

recyclables physically by weight.

3a. Heavy products like metals and glass

fall through onto the ECS, with metals being

magnetically repelled into a further bin.

3b. Papers and

types of plastics are

sorted manually.

4. Sorted products

are baled and shipped

to market for further

processing to be

recycled.

www.rogerstv.com/media?lid=237&rid=16&sid=5175&gid=104818

www.torontogardens.com/2013/09/what-happens-to-your-green-bin-toronto.html/

Landfill: Toronto’s waste goes to Green Lane Landfill. Municipal Solid Waste Landfills (MSWLF) are designed to

discourage biodegradation by isolating the waste from oxygen, sunlight, and water - all of which are

required for biodegradation to occur and discouraged in order to prevent contamination of natural systems.

The consistent and complete isolation from air occurs when the landfill has reached full capacity.

1. Landfill is divided

into stages (cells).

2. Trucks drive up to

tipping point of cell

and dump garbage.

3. Compactors and

dozers push garbage

into cell and pack it in.

Cross section of a landfill cell

4. At the end of the day the layer of garbage is topped off

with a native clayey soil to stop exposure to the air.

The top of the landfill is angled to promote

runoff of precipitation. This prevents the

formation of leachate.

A. Landfill gas is

produced from

decomposition made of

mostly methane and

carbon dioxide.

B. Gas is collected

through series of pipes

and transported to the

Landfill Gas

Management Facility.

C. Methane is safely flared to

reduce GHGs.

i. Rainwater percolates through landfill

and becomes leachate.

ii. Leachate is collected at the

bottom of the landfill and sent to

the plant by pipes.

iii. The leachate is treated

through settling and

biodegradation.

iv. The liquid is put

through a sand filter for

another cleaning and

then joins the storm

water management

system.

www1.toronto.ca/City%20Of%20Toronto/Solid%20Waste%20Management%20Services/Long%20Term%20Waste%20Strategy/Pdf/Station%203%20web.pdf

Polystyrene is pulled out and collected

until there is enough to bale. Disk Screen

Eddy Current

Sorter

3. A giant rake scrapes

off the top (plastic bags/

floating debris).

Heavy stuff

(non-organics) sink and

both parts are sent to

landfill.

2. The waste (still in

bags) gets dumped

into a Hydrapulper

with water. Similar

to a large blender,

the machine agitates

the mixture to break

bags.

4. Organics are then

mixed with anaerobic

microorganisms, acids,

and then piped to the

digester. The mix is

kept at a constant

temperature.

1. People check the tipping floor for non-organics.

5. The partially decomposed mixture

is piped then sent out. The organic

pulp is made into windrows at

another facility and left for

6 months, becoming

c compost.

Hydrapulper

Digester