8.3 Solid domestic waste

Question 1

what does SDW refer to?

Answer 1

the waste generated by households and small-scale commerical establishments

Question 2

does volume and composition of different types of SDW change?

Answer 2

yes, over time and by society

Question 3

general composition of SDW

Answer 3

Question 4

types of SDW: organic waste

Answer 4

• significant volume
• varies based on cultural practices, dietary habits, seasonal factors

composition may shift due to:
-> shifts in food preferences
-> increased composition of processed foods
-> advancements in waste management technologies that promote compositing

Question 5

types of SDW: paper and cardboard

Answer 5

• common
• derived from packaging, newspapers, magazines
• volume may shift due to:
  -> digitalisation (more people reading news online)
  -> efforts to promote recycling/reduce paper consumption

Question 6

types of SDW: plastic

Answer 6

• major component
• include packaging containers and materials, various single-use items
• volume experienced significant increase in recent decades (widespread use of plastic in various sectors)

Question 7

case study plastic waste

Answer 7

London, River Thames
- scientists collected rubbish over 3-month period at end of 2012 from 7 locations along Thames estuary
- collected over 8400 items (inclu. plastic cups, food wrapping, cigarette packaging)

Question 8

type of SDW

Answer 8

glass and metals

Question 9

type of SDW: e-waste

Answer 9

• contain toxic substances like lead, mercury, cadmium, arsenic, flame retardants -> in landfill, seep out contaminating air, water, land
• constant / extreme technical innovation > TVs, phones, computers, being replaced quickly (shortening of product lifetime)

Question 10

what metals are in phone circuit boards?

Answer 10

copper, gold, zinc

Question 11

what metal is in phone coatings?

Answer 11

lead

Question 12

what metals are in phone batteries?

Answer 12

(increasingly) lithium

Question 13

why is dismantling / reusing phones a problem?

Answer 13

devices made of increasingly complex and small parts

Question 14

non-biodegradable waste: plastic

Answer 14

• larger pieces: continously being rolled backward and forward by tidal movements > broken down into increasingly smaller fragments = easily injested by birds, fish, crabs
  -> contain smaller chemicals that (in high dosage) can harm the health of wildlife
  -> entanglement

Question 15

non-biodegradable waste: batteries

Answer 15

heavy metals and toxic substances leach harmful chemicals into soil and water, leading to contamination and healt hazards for humans and wildlife

Question 16

waste disposal methods: landfills

Answer 16

burying waste in designated areas, often lined with protective barriers

Question 17

waste disposal methods: landfills evaluation

Answer 17

pros:
- cheap
- can be lined with impermeable clay: prevents leaching
- can accomodate large range of waste types

cons:
- when biodegradable waste (like food) decomposes anaerobically, it gives off methane: ghg that contributes to global warming + is explosive
- chemicals / heavy metals pollute soil and underground water
- struggle to find new suitable areas, shortage of space
- need to be located relatively close to waste source to be economic: close to high-density populations
- living near landfill sites -> increase in health problems + birth defects
- communities often opposed to creation of new sites

Question 18

waste disposal methods: incineration

Answer 18

controlled burning of waste
- reduces volume
- converts into ash and gas particles -> combustion used to generate electricity

Question 19

waste disposal methods: incineration evaluation

Answer 19

pros:
- reduces volume > minimises space requirements
- potenital to generate electricity through combustion

cons:
- high operating + building costs
- releases air pollutants (eg. co2, so2, methane, nitrous oxide, chlorine) -> acid rain, smog, lung diease
- increased need for transport = traffic to get waste to incinerators -> air pollution, noise, vibration, accidents
- ash is often toxic + disposed in landfills

Question 20

waste disposal methods: recycling

Answer 20

converting waste into reusable materials

Question 21

waste disposal methods: recycling evaluation

Answer 21

pros:
- conserves natural resources
- reduces need for raw materials
- saves energy + reduces ghg emissions
- creates job opportunities in recycling industry

cons:
- some materials are difficult and costly to recycle
- requires energy/resources for collection, sorting, processing
- limited availability /accessibility of recycling facilities
- if waste is sent to different country to recycle: growing concern that exported plastic never reaches recycling plants

Question 22

waste disposal methods: composting

Answer 22

decomposition of organic waste into nutrient-rich soil

Question 23

waste disposal methods: composting evaluation

Answer 23

pros:
- diverts organic waste from landfills -> reducing methane emissions
- reduces need for chemical fertiliser (produces nutrient-rich compost for soil enrichment)
- helps retain soil moisture + reduce erosion
- promotes healthier plant growth and biodiversity

cons:
- requires space and proper managing
- takes time for organic waste to decompose and turn to compost
- some materials may not be suitable for composting (eg. meat and dairy)
- potential for odour/pest issues if not managed properly

Question 24

management strategies: altering human behaviour 1

Answer 24

reducing consumption
- encouraging individuals to adopt sustainable consumption patterns
- promoting awareness campaigns
- providing info about the enviornmental consequences of overconsumption
- fostering a culture of mindful/responsible purchasing habits

Question 25

management strategies: altering human behaviour 1(reducing consumption) evaluation

Answer 25

- some cultures use 3 R's due to education, compulsory in some countries VS - LEDCs: informal recycling culture, whole social groups live on / make living off landfill sites (some sort through items to find items to use or sell) -> lower end of socioeconomic scale = more likely to buy secondhand + economic pressure = less likely to waste food and more likely to reuse

Question 26

management strategies: altering human behaviour composting 2

Answer 26

composting food waste - promoting practice to divert away from landfills -> kitchen scraps, garden trimmings

Question 27

management strategies: altering human behaviour 2 (composting food waste) evaluation

Answer 27

- reduces waste volume - produces nutrient-rich compost > enrich soil fertility in gardens, farms, urban green spaces

Question 28

management strategies: controlling release of pollutants 1

Answer 28

legislation and policies - gov. plays a large role: -> incentivise recycling -> impose tax/fees on SDW collection -> discourage the use of disposable items

Question 29

management strategies: controlling release of pollutants 1 evaluation

Answer 29

- financial penalties usually works to get people to comply LEDCs: - dont have set up costs required for waste to energy programmes - even with backing from MEDCs -> poorer countries struggle to run waste to energy plant safely due to lack of expertise

Question 30

management strategies: controlling release of pollutants 2

Answer 30

recycling and reuse program - implementing comprehensive systems -> promote seperation, collection, provessing of recycable materials - includes establishments recycling facilites, providing: -> accessible recycling bins in public spaces/households - secondhand markets/community swap events

Question 31

management strategies: removing pollutant from enviornment and restoring ecosystems 1

Answer 31

landfill reclamation - rehabiliting old landfills by covering them with engineered soil covers, installing gas collection systems to capture/utilise methane emissions - if site was used for non-toxic waste/carefully managed: they can be reclaimed for alternative uses like parks, recreational sites, renewable energy facilities, stores

Question 32

management strategies: removing pollutant from enviornment and restoring ecosystems 1 evaluation

Answer 32

- reduces enviornmental impact - maximises value of previously used land (if site was used for non-toxic waste/carefully managed): - favourable economics - site can be reclaimed relitavely easily - long-lasting, costly process - gains political power

Question 33

management strategies: removing pollutant from enviornment and restoring ecosystems 2

Answer 33

waste to energy program - converting SDW to energy through inceration

Question 34

management strategies: removing pollutant from enviornment and restoring ecosystems 2 evaluation

Answer 34

- expensive - requires technology + expertise, something many countries dont have - helps reduce volume of waste that would otherwise go into landfills - generates electricity/heat (alternative energy source)

Question 35

management strategies: removing pollutant from enviornment and restoring ecosystems 3

Answer 35

clean up - collaborative efforts among organisations, governments, volunteers - mainly removing plastic waste from oceanic areas - involve use of specialised drones, nets, vessles to collect floating debris

Question 36

management strategies: removing pollutant from enviornment and restoring ecosystems 3 evaluation

Answer 36

- can be expensive -> sometimes needs specialised technology - time consuming - mitigates devastating impacts on marine ecosystems - often labour intensive

Question 37

problems caused by plastic

Answer 37

- fouls beaches > reduces potential income from tourism & recreation - entangles maring animals > drowns, strangles them and makes the immobile - plastic garbage, when washed ashore > destroys habitats - gets inside ship propellors/keels > ship maintenance more expensive - non-biodegradable > ideal medium for transfer of invasive species

Question 38

The Great Pacific Garbage Patch (GPGP)

Answer 38

- area of marine debris - central part of North Pacific Ocean - confined by ocean currents - estimated size: 700,000km2 - 15,000,000km2 - plastic is non-biodegradable, just breaks down into smaller pieces (microplastics)

Question 39

Outline two strategies for reducing the environmental impact of landfill sites. (2) ## Footnote Exam-style question

Answer 39

- locating away from surface and groundwater sources/residential areas/vulnerable or valuable ecosystems; - use of impermeable liner/clay/materials / locating above impermeable rock; - collection of methane / management to prevent spontaneous ignition;