Topic 10- Using resources Flashcards
What is sustainable development?
Development that meets the needs of current generations without compromising the ability of future generations to meet their own demands
In the UK, potable water is produced by…?
Choosing an appropriate source of fresh water
Passing the water through filter beds to remove insoluble solids
Sterilising to kill microbes (uv light, chlorine or ozone)
What are the sterilising agents for potable water?
Sterilising agents used for potable water include ozone, chlorine or ultraviolet light
Chlorine is a toxic gas so the amount added to water has to be carefully monitored
Using ultraviolet light to kill microbes avoids adding chemicals to the water but is more expensive
How is desalination carried out?
Desalination can be done by distillation or by processes that use membranes such as reverse osmosis.
These processes require large amounts of energy
What is reverse osmosis?
Sea water is passed for a membrane that only allows through the water molecules.
It needs high pressure to push the water through the membrane.
The high pressure requires a lot of energy to produce
How is wastewater produced and how is it treated?
Urban lifestyles and industrial processes produces large amounts of waste water that required treatment before being released into the environment.
Sewage and agricultural waste water required organic matter and harmful microbes.
Industrial waste water may require removal of organic matter and harmful chemicals
What are the processes involved in sewage treatment?
It includes:
screening and grit removal
sedimentation to produce sewage sludge and effluent
anaerobic digestion of sewage sludge
aerobic biological treatment of effluent
What can new methods of mining avoid in terms of disadvantages of traditional mining?
It avoids the disadvantages of traditional mining methods of digging, moving and disposing of large amounts of rock
What is phytomining?
Phytomining mining uses plants to absorb metal compounds from the soil.
The plants are harvested and then burned to produce ash that contains the metal compounds
What is bioleaching?
Bioleaching uses bacteria to produce leachate solutions that contain metal compounds
What are the main advantages and disadvantages of phytomining and bioleaching?
These methods need less energy than traditional methods, and can work on low concentration ores but are slow to carry out
Describe the stages of LCAs
Life cycle assessments are carried out to assess the environmental impact of products in each of these stages:
- extracting and processing raw materials
- manufacturing and packaging
- use and operation during its lifetime
- disposal at the end of its useful life, including transport and distribution at each stage
How do we reduce the use of resources?
The reduction in use, reuse and recycling of materials by end users reduces the use of limited resources, energy consumption, waste and environmental impact
What are the advantages and disadvantages of recylcing?
Advantages: less acid rain (pollution)/ metal ore lasts longer/ conserved energy for extraction saved/less mining/ quarrying less /waste less landfill/ creates local employment
Disadvantages: collection problems/ transport problems/ cost of transport/ difficult to separate metal from appliances/sort
What is corrosion and how is it prevented?
Corrosion is the destruction of materials by chemical reactions with substances in the environment
Corrosion can be prevented by applying a coating that acts a barrier, such as greasing, painting or electropainting. These methods stop the air or water coming into contact with the metal
