|Topics||What is the Environment | Population | Energy Flow in Ecosystems | Ecology | Biogeochemical Cycles | Biodiversity | Energy | Atmosphere | Air Quality | Global Warming | Water Quantity | Water Quality | Solid Waste|
- Solid Waste
- Any unwanted product which is not a liquid or gas in our surroundings and from our daily products.
Type of solid waste:
- mining waste (including oil and gas production) - the largest amount by volume
- agriculture waste (including food processing)
- industrial solid waste (nonhazardous)
- sewage sludge
- construction and demolition waste - sometimes included in other groups
- hazardous waste
- municipal solid waste (MSW) - waste from the community including household and commercial wastes
The rest of this page concerns only municipal solid waste.
Solid waste composition varies greatly between countries. For a comparison of waste composition between OECD countries and Asian cities see this page.
- Source reduction
- Reducing the amount of waste generated
Source reduction means no waste is produced and, therefore, none to manage.
There are no list of specific methods for source reduction. Methods will need to be applied on a case-by-case basis.
- Decreasing consumption
- Changing processes to produce less waste
- Redesigning products to make them easy to repair, resuse, or recycle
- Designing products to last longer
- Reduce packaging
- Much of packaging is done simply to sell a product (advertising, marketing, money!)
Secondary Waste Prevention
- Use a product again without destroying it
- Refillable glass bottles
- They are just washed and refilled
- Converting wastes into new products
Examples (These three examples show the different reasons for recycling)
- Production of raw aluminum is by electrolysis, which consumes a large amount of electricty (aluminum production consumes about 15kWh per kilogram. Aluminum production represents 5% of US electicity)
- Recycling aluminum only requires melting of aluminum, and therefore, uses only 5% of the energy used to make it from ore.
- Paper accounts for a large percentage of solid waste (more than 30% in some countries)
- Therefore, recycling reduces landfill space considerably.
- Electronic waste (e-waste)
- Electronic waste contains many valuable materials: gold, silver, aluminium, platinum, palladium, copper, tin, tantalum, nickel, lithium
- However, recover of some materials requires use of very strong acids
- Electronic waste also contains many toxic chemicals: mercury, lead, cadmium, chromium, beryllium
- Using soil microorganism to decompose organic matter
- Especially useful for food wastes, especially at the household level
- Controlled burning of solid waste
- reduces volume
- produces energy
- produces air pollution
- toxic ash
- burying waste underground in a specially built site
- A clay base
- A plastic liner
- Daily soil cover
- Top clay layer (applied when landfill is full)
Two things landfills create:
- Methane gas
- Can create dangerous pockets
- Can be recovered for use as fuel
- A liquid called leachate
- can get into groundwater
- collected by a leachate collection system