For SL and HL, Topic 7.3 Solid waste: landfill is inexpensive but can cause long-term pollution; incineration reduces waste volume but may release pollutants; recycling conserves resources but requires energy, sorting and viable markets. No option is universally best because sustainability depends on the waste type and local context.
How the Options Compare
Waste becomes pollution when harmful substances enter an environment faster than they can be degraded or transformed into harmless substances. Each option distributes environmental, social and economic costs differently.
| Option | Advantages | Disadvantages |
|---|---|---|
| Landfill | Relatively cheap; accepts mixed waste; landfill gas can provide energy; engineered liners and leachate collection reduce pollution. | Occupies land; decomposition releases methane; toxic leachate may contaminate soil and groundwater; odour, pests and site location can create environmental-justice concerns. |
| Incineration | Greatly reduces waste volume; destroys pathogens; heat can generate electricity in waste-to-energy plants; reduces demand for landfill space. | Expensive to construct and operate; releases carbon dioxide; inadequate controls may release particulates, nitrogen oxides or toxic compounds; ash still requires disposal. |
| Recycling | Conserves natural capital; reduces extraction of virgin materials and landfill demand; supports a circular economy by circulating materials. | Collection and sorting require money and energy; contamination reduces quality; some materials have limited recycling cycles; weak markets can make recycling uneconomic. |
A common misconception is that recycling has no environmental impact. It still requires transport, processing and energy, and it is better classified as waste management than final disposal. In the waste hierarchy, prevention and reduction are normally more sustainable than recycling, incineration or landfill.