Lecture 23 - waste management

microplastics are defined as plastic less than _____ in size?

5 mm

where do microplastics come from?

• cruise ships

• open dump areas

• incinerators

why do we say waste is a uniquely human concept?

only humans produce some waste products that cannot be easily broken down

which 2 principals do we violate?

matter cycles and toxins

violating matter cycles

preventing decomposition

violating toxins

releasing into the environment

waste

any unwanted material or substance that results from a human activity or process

what is municipal solid waste (txbk)

everyday waste produced by individuals

municipal solid waste

non-liquid waste that comes from homes, institutions, and small businesses

industrial solid waste

waste from production of consumer goods, mining, agriculture, and petroleum extraction and refining

hazardous waste

solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive

e-waste

unwanted computers and other electronic devices such as discarded televisions and cell phones

where does most municipal waste come from?

• packaging and nondurable goods

  • products meant to be discarded after a short period of time

biodegradable

materials are those that can be broken down by other organisms through primarily aerobic processes. Once broken down it can be reused within ecosystems

degradable

materials can be broken down by chemical and physical reactions

nondegradable

materials are made of very stable molecules and so never break down—at least not in a human time scale.

open dumps

waste generation in developing countries supplies income for people

danger and health risks are concerns

leachate can runoff dumps and enter groundwater

garbage not well contained on site - blow into nearby waterways

sanitary landfills

waste buried in the ground or piled in large, engineered mounds

• engineered to minimized leakage of contaminants

  • leachate

  • methane gas

why is the rate of decomposition so slow in a landfill?

bacteria can decompose waste in an oxgyen-deficient environment - but slowly

landfill gas

a mix of gases that consists of roughly half methane

• can be collected, processed, and used like natural gas

• when not used commercially, landfill gas is burned off in flares to reduce odors

why is canada’s waste so high?

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what do we mean by diverting waste?

~

composting

the conversion of organic waste to mulch or humus through natural biological processes of decomposition

why does composting not produce methane gas like decomposition in a closed landfill?

oxygen!!!

• composting is an AEROBIC process, so decomposition does not produce methane.

4 R’s

refuse, reuse, reduce, recycle

financial incentives can help address waste

• pay-as-you-throw

• return-for-refund

• take back laws

• extended producer responsibility

pay-as-you-throw

uses financial incentives to influence consumer behavior

• the less waste a house generates the less it is charged for trash collection

return-for-refund

consumers pay a deposit, and receive a refund for returning used bottles

take back laws

require companies to take a produce back from a consumer when the consumer is finished it

extended producer responsibility

a policy approach that requires producers (i.e., brand owners, importers, manufacturers) to manage and pay directly for the recycling or other end-of-life waste management of their post-consumer products.

source reduction

preventing waste generation in the first place

• avoids costs of disposal and recycling

• helps conserve resources

• minimizes pollution

• can save consumers and businesses money

strategies for source reduction

• reduce packaging

• ban on plastic grocery bags or produce we can refuse to use

• increase the longevity of goods

reducing packaging…

• produce bags

• meat trays

• amazon packages