Solid Waste
Environmental Science | |
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Topics | What is the Environment | Population | Ecological Footprint, Food, and Urbanization | Ecology - Definitions and Outline | Energy Flow in Ecosystems | Population and Community Ecology | Biogeochemical Cycles | Biodiversity | Energy | Atmosphere and Climate | Global Warming | Air Quality | Water Quantity | Water Quality | Solid Waste |
Discuss what is solid waste, source reduction, secondary waste prevention (for example, recycling), and final disposal |
Contents
Introduction
Definition
- Solid Waste
- Any unwanted product which is not a liquid or gas in our surroundings and from our daily products.
Types
Type of solid waste:
- mining waste (including oil and gas production) - the largest amount by volume
- agriculture waste (including food processing waste, but not household food waste)
- industrial solid waste (nonhazardous)
- sewage sludge
- construction and demolition waste - sometimes included in other groups
- hazardous waste (wastes which are flammable, corrosive, reactive, or toxic)
- municipal solid waste (MSW) - waste from the community including household and commercial wastes
The rest of this page concerns only municipal solid waste.
Composition
Solid waste composition varies between countries. For information on different solid waste compositions see report (pdf)
What do we do with solid waste
Bad
- Open dumping
- Improper landfills
- Uncontrolled burning ("open burning")
- Exporting of wastes (especially E-waste)
Good
- 3Rs, composting
- Proper landfills, incinerators
3Rs
Electronic waste (E-waste)
Electronic waste contains many valuable materials: gold, silver, aluminium, platinum, palladium, copper, tin, tantalum, nickel, lithium.
However, to recover some of these requires use of very strong acids. This can lead to problems with health and safety.
Electronic waste also contains many toxic chemicals: mercury, lead, cadmium, chromium, berylium.
Source Reduction
Definition
- Source reduction
- Reducing the amount of waste generated
Source reduction means no waste is produced and, therefore, none to manage.
Methods
There are no list of specific methods for source reduction. Methods will need to be applied on a case-by-case basis.
Methods include:
- 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!)
- Taxes (especially recently on single-use plastics)
- Bans (especially on nonrecyclable products)
Secondary Waste Prevention
Reuse
- Reuse
- Use a product again without destroying it
Example
- Refillable glass bottles
- They are just washed and refilled
Recycling
- Recycling
- Converting wastes into new products
Examples (These three examples show the different reasons for recycling)
- Aluminum
- 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
- 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
Composting
- Composting
- Using soil microorganism to decompose organic matter
- Especially useful for food wastes, especially at the household level
Waste Management
Incineration
- Incineration
- Controlled burning of solid waste
Pros
- reduces volume
- produces energy
Cons
- produces air pollution
- toxic ash
Landfills
- Landfill
- burying waste underground in a specially built site
Landfill includes:
- A clay base
- A plastic liner
- Daily soil cover
- Top clay layer (applied when landfill is full)
Two things landfills create:
- Methane gas
- Is a greenhouse 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