9.6 Urban Waste & Disposal

• Why is waste increasing?

  • rising population
  • expensive to buy local/organic foods
  • poor collection of waste
  • urbanisation
  • convenience
• Waste management strategies:

  • recycling
  • incineration
  • landfill
  • trade
• Impacts of increasing waste generation:

  • the cost of collecting and treating waste are high
  • environmentally waste is a large source of methane
  • untreated waste can lead to health conditions
• Waste trade:

  • waste may be moved between and within countries
  • toxic or hazardous waste are often exported from high to low income countries
  • however, these countries often do not have safe recycling processes or facilities.
• Landfill waste:

  • the placement of waste, such as pits which can be naturally or constructed

  Pros - makes good use of abandoned quarries, easily managed and methane can be vented and used as a fuel

  Cons - attracts vermin and flies, produces methane, leachates percolating into groundwater can be toxic and the smell is unpleasant.
• Incineration waste:

  • can reduce the volume of disposed waste by up to 90%.the process of burning hazardous materials at temperatures high enough to destroy contaminants.

  Pros - produces energy from burning MSW, heat, steam and ash produced are valuable resources, requires less land and is a long life span

  Cons - particulate emission requires managing, chimney emissions can be toxic if not managed and carbon dioxide emissions are greenhouse gas.
• Recycling

  • the selective extraction of disposed materials for a specific next use

  Pros - doorstep wheelie bin collection sanitary, convenient & popular, organic waste can be composted and sold and there is less landfill

  Cons - public collection points can generate litter, public separation of paper, plastic etc which is inconvenient and prone to error. Public recycling facilities require expensive operation
• Dharavi Recycling

  • 15,000 single room factories
  • employs 1/4 of a million people
  • ragpickers go through waste, bad conditions
  • paperman is a non-governmental organisation, which helps to promote and create awareness about recycling
  • recycles up to 80% of all waste material
• WRWA - Western Riverside Waste Authority, London

  • 7 million tonnes of waste in London a year
  • treatment and recycling of waste
  • handles 6,000 tonnes a week
  • waste crushed and loaded into containers and transported to Belvedere. Burned to produce energy used to run buildings
  • technology separates items but plastic bags manually removed
  • all items comes out in murph blocks to be recycled