Lecture 3&4 - Management of Non-Hazardous Waste

Question 1

Define non-hazardous waste

Answer 1

The US Environment Protection Agency defines non-hazardous waste as any garbage, refuse or sludge. When improperly disposed, they can bring abt various types of hazards & cause econo, socia, environ impacts

Question 2

Name characteristics of non-hazardous solid wastes

Answer 2

• non-flammable
• non-corrosive
• non-reactive (w air, water or anything else)
• non-toxic

Question 3

Why manage waste?

Answer 3

Use of resources during IR to mass produce high demand goods + dvlpment of densely populated urban cities = accelerated product n of waste

Rapid increase in amt of waste -> more contaminated environ and health safety hazard
=>impt study mgmt of waste

Question 4

Why do cities impact their surrounding regions? (What is happening in and around cities?)

Answer 4

1. Conversion of landuse
2. Inadequately treated waste
3. Increased Demand for city-based activities
4. Environ degradat n of surrounding regions

Question 5

Describe the relationship between cities and surrounding regions

Answer 5

Very close r/s
- surrounding region highly affected by environ problem produced by urban city
-main cause of such urban issues is linear nature of Urban Metabolism

Question 6

What is urban metabolism?

Answer 6

study of material and energy flows arising fr socio-economic activities of cities and regional and global biogeochemical processes

->a framework studying interact n btw natural and human system in cities (eg water, energy, ppl, food etc)

Question 7

Current Linear urban metabolism is …

Answer 7

disruptive of natural cycles, promotes waste and undermines goal of SUD

Question 8

Cities generally based on … metabolism?
Elaborate

Answer 8

Linear metabolism
- extract raw material, make product to consume and dispose
=>diff impacts eg deplet n of natural resource, high dependancy on non-renewable ones
=>most pollut n come fr cities or agriculture (eventually feeding cities) by emissions, discharge of waste into local and global environ

Question 9

How can cities be sustainable?

Answer 9

Develop self-regulating systems,
- within city (eg waste management system)
- within country (w rural areas and other cities)

=> achieved thru Circular Urban Metabolism
- Every output by organism is also input
- Renew and sustain whole living environ

Question 10

What is ecological footprint? Explain

Answer 10

amt of biologically productive land needed to produce energy, food & gd consumed & absorb waste

• resource mgment tool measuring human consumpt n of natural resources compared to Earth’s ecological capacity to regenerate them
• now widely used globally as indicator of environ sustainability, measure and manage use of resource thru out econ

Question 11

How to measure ecological footprint (EF)?

Answer 11

typically expressed as ‘global hectares (gha) per person/capita’

calculated by:
gha of total productive land and water on earth demanded or consumed by world’s pop n

Question 12

Why do DCs hv higher ecological footprint? How can it be fixed?

Answer 12

-more affluent w higher incomes, so high demand for energy resource and goods
-much higher rate of resource and energy consumption (2018)
=> consume a lot of resources AND tend to generate more waste and pollut n.
Therefore, issue of waste in DC abt Reducing:
- ecological footprint (change consumpt n patterns, mindsets, etc)
-amt of waste produced (3Rs to manage waste)

Question 13

Give two examples of effects of waste accumulat n in LDCs

Answer 13

• Jakarta, Indonesia
  40% of solid waste uncollected, much washed into water courses eg drainage, river, roadsid
  -> extensive flood during flooding season
  -> attract pests (eg rats), disease vectors (insects eg cockroach, mosquito, fly) lead to pestilences,
  ->contaminate water sources thru leaching process
• India
• In cities like Delhi, the burning of waste, vehicle emis n, industrial pollu n contributes to city’s severe air pollution problem
• poor air quality caused rise in respiratory issues, asthma, & other health problems among pop n.
• During certain times of the year, (eg winter season) situation worsens due to temperature inversions trapping pollutants close to ground, creating a hazardous environment.

Question 14

Compare problem of urban waste in DCs and LDCs

Answer 14

DCs
- affluent cities ->produce too much waste
BUT
-hv financial means, knowledge and tech means to manage waste
- need to and can afford to think abt ways to cut down waste and reduce EF (sustainable use of resources)
- more focused on waste reduct n (stop making waste) by influence consumpt n patterns AND recycling waste

LDCs
-relatively lower demand for goods than DCs as majority of pop n generally poor ->less concerned abt their EF currently
-more concerned abt dealing w urban waste, ie. accumulat n of uncollected waste AND unregulated dumping of waste (eg Yamuna River, longest tributary of India’s Ganges River)
=> more focused on dvloping proper waste disposal methods thru public edu n, laws, etc.

Question 15

Why is waste a transboundary issue? Give an eg

Answer 15

Problem of waste not confined to specific scale
-DCs can dump waste onto LDCs where legislat n less stringent or poorly enforced
eg. Guiyu Waste Dump, Shantou, China
–>City employ abt 15 000 e-waste workers working thru 16h days disassembling old computers and finding reusable/recyclable parts
–>create air and water pollut n
–>Implications on health
eg
82% of young children in Guiyu had conc of Pb in blood > 100, which is unsafe according to health experts

*The problem can magnify into a global problem; affects achieving SD

Question 16

Expound on waste as a transboundary issue. What has been done to curb waste?

Answer 16

• all waste disposed back into environ
  =>some disposed of controllably by collect n and treating first
  =>when waste disposed in air, river, ocean (which are publicly owned), common ownership of environ -> unregulated emission of waste
• International treaty -> format n of Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal in 1992
  =>ensure mvment of waste only permitted when directed to enough disposal facilities in importing country
  =>prevent transfer of hazardous waste from DCs to LDCs

Question 17

Name some waste management strategies

Answer 17

1. Dump waste on landfill
2. Incinerate waste
3. Alternative strategies (eg 3Rs, taxation)

Question 18

Elucidate effectiveness of dumping waste at landfills

Answer 18

Useful
-cheapest, easy way to deal w waste for cities/country w large available land
-A lot of waste can b dumped, esp mgment of municipal waste
- When properly designed, can provide surface other landuses eg reforestat n, playing field, recreational sites (like Pulau Semakau in SG) BUT not heavy structures like housing

Limitat n
- Poorly managed (or landfill lining breaks -> (a) organic waste decompose, release methane (x 84 more potent ghg than CO2 in absorbing Sun radiat n) (b) Poses as fire hazard
- leakage of leachate (made by landfill sites) -> contaminate both surface, groundwater (leachate high lvl amonia, bcome nitrate, goes to water sources, cause eutrophication, gr8ly lower O2 lvl fr excess algae growth, -vely affect ecosystems, oso may contain toxins eg mercury)
-infesta n ->spread of diseases and pestilences eg Bantar Gebang Landfill in Jakarta, Indonesia
-pose threat to health, significant 12% increased risk of congenital malformat n in children
-health hazards
- Large landfills on avg decrease adjacent land value by 12.9%

Question 19

Elaborate on Pulau Semakau in SG

Answer 19

• most of SG’s trash incinerated on mainland B4 transported to Semakau landfill (ash high cost abt $610m and expected fully filled by 2035)
• Bund well-lined w impermeable membrane and layer of marine clay (prevents leakages)

Question 20

Explain effectiveness of incinerating waste

Answer 20

controlled burning of waste at high temperature, designed attain complete combustion
-> break down waste into ash

Useful
1. Reduce bulk of waste, easily buried at landfills (eg SG, licensed waste collect n companies collect waste to inci plant; ashes transported to
Semakau landfill)
2. Break down hazardous compound
3. combined w energy recovery (convert waste into energy), used for heating and electricity
eg worn tires act as alternative fuel power cement kilns in Gladstone Industrial Area, Australia
4. ash useful in construction, ie. building bricks ->reduce waste, consumpt n of new materials

Limitat n
1. Release harmful emissions eg carcinogenic highly toxic dioxins, CO, CO2, SO2 into atmosphere
2. Site select n controversial due to associated health risk
3. Still need landfills (often in poor and minority communities eg areas w large no of immigrants)

Question 21

Expound on effectiveness of reuse and recovery of waste

Answer 21

Useful
When economically viable, it reduces
-resource consumpt n
- cost of disposal
- inadequacies of disposal
=>what is considered waste today can bcome resource tomorrow
eg Composting, biodegradable waste for use as fertiliser

• informal scavenging provide jobs to desperate individuals
  eg Asian, Latin America cities (Bangladesh, Ph, Mexico, Nicaragua, etc) up to 2% of pop n earn living by scavenging, recover, material to sell for reuse or recycle (provide income to >15 million ppl globally, financial impact of several billion US$ annually)

Limitat n
-high costs
-time required for such innovat n to b discovered
-health hazards to the poor
eg Guiyu e waste dump cause lead poisoning, etc.

-abuse of child labour

Question 22

Explain effectiveness of recycling in reducing waste

Answer 22

Useful
-large energy saving -> less resource extracted for new product
- minimise environ impact thru waste reduction (less pa on land resource and related environ, health hazards)
-glass, wastewater, aluminium, steel, sludge can b recycled

Limitat n
- High cost involved (dumping abt $50/ton but recycling abt $150/ton)
-no guarantee good quality products, may hv weaker structure

Eg recycling wastewater in Mexico (LDC)
- wastewater fr most cities used irrigate 150000ha crops
BUT
- sewage contain heavy metal, accumulate in soil and uptake into crops
- increased parasitic infection among agri worker & their family due to expose to raw sewage

eg2 Accra, Ghana
- recycling efforts r hindered by lack of formal infrastructure, reliance on an informal waste-picking sector
- poor waste segregat n, minimal govt support, limited public awareness contribute to low recycling rates. Much of waste end up in landfills, causes pollution.
- absence of strong policies and waste management systems has led to ineffective recycling and environmental challenges.

Question 23

Explain effectiveness of taxation in reducing waste

Answer 23

Useful
-encourage both waste reduct n and increase recycling rates
eg in 1980s, Denmark had waste taxation scheme promoting reuse and recycling to address concerns w running out of landfill space and high lvl of air pollut n fr incinerator -> waste reduced and overall recycling rate increased
-imposition of tax on packaging incorporate full social cost of product into retail price by include cost of disposal of wrapping

Limitat n
-Limited by community participat n and govt’s commitment (due to fear of losing investment/business competitiveness)

Question 24

Describe take-back programme by producers, to reduce waste

Answer 24

manufacturer of product takes responsibility for environmental impacts thruout whole cycle; onus on producer to eliminate waste