Samenvatting M&C
Living in the Environment
CHAPTER 21 – SOLID AND HAZARDOUS WASTE
21.1 What environmental problems are related to solid and hazardous wastes?
Solid waste contributes to pollution and includes valuable resources that could be reused or recycled.
Hazardous waste contributes to pollution, as well as to natural capital degradation, health problems
and premature deaths.
In a natural world, the wastes of one organism become nutrients or raw materials for others.
By mimicking nature, through strategies such as cradle-to-cradle design, we could reduce this waste
of potential resources and the resulting environmental harm by up to 80%.
The solid items thrown away in your household fall into the category of solid waste: any unwanted of
discarded material people produce that is not a liquid or a gas.
Major types of solid waste:
1. Industrial solid waste: produced by mines, farms and industries that supply people with
goods and services.
2. Municipal solid waste: garbage or trash. Solid wastes produced by homes and workplaces
other than factories.
Hazardous/toxic waste: any discarded material or substance that threatens human health or the
environment because it is toxic, is corrosive, is flammable, can undergo violent or explosive chemical
reactions or can cause disease. Improper handling of these wastes can lead to pollution of air and
water, degradation of ecosystems and health threats.
Main classes of hazardous waste:
1. Organic compounds
2. Toxic heavy metals
21.2 How should we deal with solid waste?
A sustainable approach to solid waste is first to produce less of it, the to reuse of recycle it and finally
to safely dispose of what is left.
,Waste management: focuses on controlling wastes in order to limit their environmental harm but
does not attempt to seriously reduce how much waste is produced.
Waste reduction: producing much less solid waste and reusing, recycling or composting what is
produced.
Integrated waste management: a variety of coordinated strategies for both waste management and
waste reduction.
The four R’s of waste reduction:
- Refuse: don’t use it.
- Reduce: use less of it.
- Reuse: use it over and over.
- Recycle: convert used resources to useful items and buy products made from recycled mate-
rials.
Composting: mimics nature by using bacteria and other decomposers to break down yard trimmings,
vegetable food scraps and other biodegradable organic wastes into materials than can be used to
improve soil fertility.
Six strategies to reduce resource use, waste and pollution:
- Change industrial processes to eliminate or reduce the use of harmful chemicals.
- Redesign manufacturing processes and products to use less material and energy.
- Develop products that are easy to repair, reuse, remanufacture, compost or recycle.
- Establish cradle-to-cradle responsibility laws.
- Eliminate or reduce unnecessary packaging.
- Use fee-per-bag solid waste collection systems.
21.3 Why are refusing, reducing, reusing and recycling so important?
By refusing and reducing resource use and by reusing and recycling what we use, er decrease our
consumption of matter and energy resources, reduce pollution and natural pollution and natural
capital degradation and save money.
Categories recycling:
1. Upcycling: recycled into a form that is more useful than the recycled item was.
2. Downcycling: the recycled product is still useful, but not as useful or long-lived as the original
item.
Types of recyclable materials:
- Paper products
- Glass
- Aluminum
- Steel
- Some plastics
Primary recycling involves using materials, such as aluminum, again for the same purpose.
Secondary recycling involves downcycling or upcycling waste materials into different products.
, Types of recyclable wastes:
- Preconsumer/internal waste: generated in a manufacturing process.
- Postconsumer/external waste: generated from use of products by consumers.
Steps recycling:
1) The collection of materials for recycling
2) Conversion of recycled materials to new products
3) Selling and buying of products that contain recycled material
In materials-recovery facilities, machines and workers separate the mixed waste to recover valuable
materials for sale to manufacturers as raw materials.
Plastics consist of various types of large polymers, or resins (organic molecules made by chemically
linking organic chemicals produced mostly from oil and natural gas).
Advantages and disadvantages of recycling:
Advantages Disadvantages
Reduces energy and mineral use and air and Can cost more than burying in areas with ample
water pollution landfill space
Reduces greenhouse gas emissions Reduces profits for landfill and incinerator
owners
Reduces solid waste Inconvenient for some
21.4 What are the advantages and disadvantages of burning or burying solid waste?
Technologies for burning and burying solid wastes are well developed, but burning can contribute to
air and water pollution and greenhouse gas emissions, and buried wastes can contribute to water
pollution.
Heat released by burning trash can be used to heat water or interior spaces, or for producing
electricity in facilities called waste-to-energy incinerators.
Advantages and disadvantages of waste-to-energy incinerators:
Advantages Disadvantages
Reduces trash volume Expensive to build
Produces energy Produces a hazardous waste
Concentrates hazardous substances into ash for Emits some CO₂ and other air pollutants
burial
Sale of energy reduces cost Encourages waste production
In a sanitary landfill, solid wastes are spread out in thin layers, compacted, and regularly covered
with a layer of clay or plastic foam.