Alternative Approaches to Waste (AQA A Level Geography)

• There are many ways to manage urban waste
• Ultimately, effective management is essential to reduce the environmental impact of municipal solid waste (MSW)
• The most recognisable method are the 3Rs of reduce, reuse and recycle
  • This encompasses the principle of reducing consumption of products - not using single use plastics, buying only what is needed
  • Repurposing items - using plastic carrier bags as bin liners or cola bottles as cloches to protect new seedlings 
  • Recycling items such as paper, glass etc. 
  • The benefit is that waste is reprocessed into new products which reduces demand for raw materials and decreases the environmental impact. Also, less energy is used, reducing CO2 emissions
  • However, recycling does require new infrastructure of collecting and processing facilities, which do add to greenhouse emissions and air pollution

Incineration

• Waste is burnt, which reduces the volume of waste to landfill, but the remaining ash needs to be disposed of
• Burning waste can generate electricity in a process called energy recovery
• This reduces the use of fossil fuels, but can lead to the release of toxic chemicals into the air or water
• It involves burning waste at very high temperatures, and the heat released is used to convert water to steam
• The steam is sent to a turbine generator to produce electricity
• The waste ash is collected and taken to a specialised landfill
  • But the ash can be contaminated with toxins that can leach out into the environment
• Particulates are captured by high-efficient filtering
• Energy recovery incineration is better than simple incineration because:
  • It disposes of gas, liquid and solid waste
  • It is a practical method of disposing of certain hazardous waste materials (such as biological medical waste).
  • Waste ash can be repurposed in roads and concrete (depending on type of ash)
  • Waste ash can also be reprocessed to extract recyclable metals and glass
  • High-efficiency filters remove many of the emissions
  • It reduces the amount of landfill waste 

Landfill

• Landfill is the burial of waste in hollowed out land, where it is left to decompose over time
• Waste can also be buried in disused/abandoned mines and quarries
• In the past, landfill sites were unmanaged and prevention of environmental damage minimal or non-existent
• Modern landfill sites are lined to prevent leachate from running out of the site
• Leachate is collected in pipes and transferred to special leachate ponds, where it is treated to reduce environmental damage
• Methane is produced as decomposition begins, which is either flared off or collected and used to generate electricity (gas to energy process)
• Closed landfill sites are landscaped and used as golf courses or housing etc. However, many older landfill sites are still contaminated and releasing methane into the atmosphere
• Landfill sites are 'smelly' and attract vermin and rainwater can surface wash chemicals into rivers
• In the UK, there is a general lack of space for any new landfill sites

Impacts of the Methods of Waste Disposal

Waste Disposal	Method	Impact
Unregulated	Waste is dumped on unofficial sites	Ecosystems are damaged, rivers and groundwater polluted, wildlife can be trapped in waste, unwanted vermin that can transmit diseases
Recovery	Waste is re-purposed into new products - concrete crushed to use as base for new roads and buildings	Reduces amount of waste to landfill and demand for natural resources
Recycling	Waste is reprocessed to produce a new product - plastic bottles into fleece coats	Reduces demand on raw materials, reduces greenhouse gas emissions, uses less energy. However, does require new infrastructure and collection points
Submergence	Waste is dumped at sea - illegal but some countries still do this	Submerged waste is usually toxic and radioactive which leaks into the ocean damaging ocean ecosystems
Trade	Waste is bought and sold by countries and shipped around the world	Receiving country may not have regulations in place or have the capacity to safely process waste. Source country still counts exported waste as locally recycled waste in its annual figures
Incineration	Waste is burnt at high temperatures	Energy recovery reduces the use of fossil fuel, less waste is sent to landfill. However, toxic chemicals and ash can be released into the atmosphere. Ash waste needs to be disposed of in specialised landfill sites as they are concentrated chemical contaminants
Landfill	Waste is buried and allowed to decompose over time	Methane can be used to generate electricity. Smelly and attract vermin. Leachate needs to be collected to prevent waterway contamination