Waste Disposal (HL IB Environmental Systems & Societies (ESS))

Waste Disposal Methods

• Waste disposal is critical in managing and minimising the environmental impact of waste

• Various methods are available

  • Each has advantages and disadvantages that should be taken into account when considering their impact on societies and ecosystems

1. Landfill sites

• Landfills involve burying waste in designated areas in large holes dug into the ground

Advantages

• Centralised waste management: provide a single location for managing large volumes of waste

• Flexible: handle a wide range of materials, including non-recyclable materials

• Lower operational costs: relatively inexpensive compared to other waste disposal methods

• Reduced environmental impact: can be engineered with liners and leachate collection systems to minimise environmental impact

• Gas capture potential: some capture methane gas, which can be used as an energy source

Disadvantages

• Methane generation: produces methane, a potent greenhouse gas

• Land requirements: needs significant land, which can be difficult to find

• Risk of contamination: potential for groundwater and soil pollution from leachate

• Long-term monitoring: requires management long after closure

• Environmental injustice: often causes noise and smell pollution in less affluent urban outskirts

  • This disproportionately impacts the health and quality of life of residents in these areas

2. Incineration

• Incineration involves burning waste materials at high temperatures to reduce their volume

Advantages

• Reduces waste volume: drastically cuts down the physical size of waste

• Less reliance on landfills: reduces amount of waste sent to landfill sites

• Handles hazardous waste: can process hazardous materials safely

Disadvantages

• Air pollution: emits harmful gases and pollutants, including greenhouse gases

• High operational costs: requires expensive technology and maintenance.

• Ash disposal: produces toxic ash that requires careful disposal

• Public concern: communities often oppose incinerators due to health and environmental concerns

3. Waste-to-energy (WtE)

• Waste-to-energy (WtE) or energy-from-waste (EfW) plants burn waste to generate electricity or heat

Advantages

• Energy recovery: converts waste into usable energy, reducing reliance on fossil fuels

• Reduces landfill use: decreases the amount of waste sent to landfills

• Waste volume reduction: significantly reduces the amount of waste

Disadvantages

• Pollution risks: can release harmful emissions and greenhouse gases unless controlled properly

• High capital investment: expensive to build, operate and maintain WtE plants

• Limited by waste composition: not all types of waste can be efficiently converted to energy

• Not a perfect solution: still encourages waste generation instead of focusing on reduction and recycling.

4. Exporting Waste

• Exporting waste involves sending waste materials to other countries for treatment, recycling or disposal

Advantages

• Offloads waste responsibility: countries with waste management challenges can send waste to others

• Reduces domestic pressure: eases the burden on local waste management systems

• Access to advanced facilities: may provide waste producers with access to specialised waste treatment options

• Economic benefit: may be cheaper for some countries to export waste than to process it locally

Disadvantages

• Environmental injustice: exporting to low-income countries may cause environmental and social harm there, raising ethical concerns

• Environmental impact of transport: shipping waste long distances increases carbon emissions

• Legal risks: can lead to legal issues between exporting and importing nations

• Long-term effects: does not help solve the root cause of excessive waste generation

5. Recycling

• Recycling involves converting waste materials into new, usable products

Advantages

• Resource conservation: saves raw materials and reduces the need for new resource extraction, which can be environmentally damaging and polluting

• Energy savings: recycling typically uses less energy than producing new materials

• Economic cost: may be cheaper than other waste disposal options

• Reduces landfill and incineration: keeps recyclable materials out of waste disposal facilities

Disadvantages

• Energy use in processing: sorting, collecting and processing recyclables can be energy-intensive

• Limited recycling facilities: availability and access to recycling facilities can vary between countries and regions

• Contamination: contaminated recyclables can reduce the efficiency of the recycling process

• Limited market: not all materials are recyclable and there can be limited demand for recycled products

6. Composting

• Composting is the process of breaking down organic waste into nutrient-rich soil

Advantages

• Environmentally friendly: composting produces natural fertilisers, reducing the need for chemical alternatives

• Reduces landfill waste: organic matter is kept out of landfills, lowering methane emissions

• Enriches soil: compost improves soil health and can enhance crop growth

• Low cost: can be done on a small scale at home or in local communities

Disadvantages

• Limited to organic waste: can only handle biodegradable materials

• Space and time requirements: requires space for compost piles and can take time to break down waste

• Potential for odour: if not properly managed, composting can create unpleasant smells