5.5 Solid domestic waste

“A Rubbish Map – A Global Comparison of Garbage.” The Economist. The Economist Newspaper, 07 June 2012. Web. 06 Mar. 2014.

A global comparison of garbage

NOTHING evokes environmental degradation and poverty quite so vividly as pictures of slum-dwelling children scavenging through mounds of steaming waste for items to sell. Such sights are often a direct consequence of economic success and rapid urbanisation, and so could become increasingly common as the rate of urbanisation in many poor countries increases. Nearly all rubbish is generated by city-dwellers, and in a new report on municipal solid waste (MSW), the World Bank warns of the potential costs of dealing with an ever-growing deluge of garbage. The world’s cities currently generate around 1.3 billion tonnes of MSW a year, or 1.2kg per city-dweller per day, nearly half of which comes from OECD countries. That is predicted to rise to 2.2 billion tonnes by 2025, or 1.4kg per person. The Bank estimates China’s urbanites will throw away 1.4 billion tonnes in 2025, up from 520m tonnes today. By contrast, America’s urban rubbish pile will increase from 620m tonnes to 700m tonnes.

TASK: Spearman’s rank practice – create waste data table using Waste Generation by Country 2009 (kg/capita) and GDP per capita data using CIA World Fact Book  to complete your statistical test. Show all your working. This will be collected in for assessment.

Waste and Sustainable Development

Since the Rio Earth Summit (1992) Agenda 21, the United Nations Action Plan (and subsequent updates) for the twenty first century, has been initiated. One of the aims of Agenda 21 was to encourage a move away from the unsustainable development of recent decades which took little account of the finite nature of resources or the damage being done to our environment. So, sustainable development has since been deemed essential.

Member countries have had to formulate plans and strategies for sustainable development. In turn, governments have been obliged to formulate national plans and strategies, and to think about ways in which Local Authorities can help to implement these strategies. One aspect of this is to consider ways in which waste can be better managed.

Agenda 21 acknowledges “environmentally sound waste management must go beyond the mere safe disposal or recovery of wastes that are generated and seek to address the root cause of the problem by attempting to change unsustainable patterns of production and consumption.” This implies the application of life-cycle management concept, which presents a unique opportunity to reconcile development with environmental protection. Agenda 21 proposes four waste- related programme areas: a) Minimising wastes; b) Maximising environmentally sound waste reuse and recycling; c) Promoting environmentally sound waste service coverage

TASK: Brainstorming and class discussion…

  • What is solid domestic waste?
  • How can waste be categorised?
  • How do we manage (collect and dispose) waste?

2014-03-11 11.34.22

What options are available for waste management in Singapore?

Click on the image below to find out more…

Screen Shot 2014-03-11 at 2.59.33 pm

TASK: Using Singapore as a mini case study, illustrate how waste can be managed.

In your case study include:

  • the proportion or total volume of different types (categories) of wastes produced in Singapore
  • the various waste disposal methods, their locations and the collection methods of solid municipal waste  in Singapore
  • the reasons for the choices of waste disposal methods
  • an evaluation of the different waste disposal methods
  • include specific facts and statistics

Resource substitution: using waste to produce energy

[links with topic 3.3 Energy Resources and 3.7 Limits to Growth]

A possible solution to the problem of waste is to incinerate it. There are problems with incineration as it can lead to dangerous chemicals being sent into the air. However, waste can be viewed as an energy store, which can be used to generate electricity and produce heat, so acting as a substitute for other energy sources. Glass and metals have only a small energy content, but once they have been removed, general household waste has an energy value one-third that of coal. The techniques that are at present used to recover energy from waste include anaerobic digestion, landfill gas and incineration (e.g.Tuas Incineration Plant in Singapore and landfill/land reclamation at Semakau – Case study).

Anaerobic digestion is a way of producing fuel from the organic material in household waste (see figure below).

How anaerobic digestion produces biogas fuel (i.e. methane)

As waste dumped in landfill sites decays it produces landfill gas. In larger landfill sites this gas can be used to generate electricity. At present many MEDC landfill sites are generating electricity in this way, which is sold to national grids.

Recycle City Activity Sheet – Click on the image to be directed to the website.

recycle city

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