C10 : 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 needs
In the UK , potable (safe to deink) water is produced by … ?
- choosing an apporopiate source of fresh water
- passing the water through filter beds to remove any solids
- sterlising to kill microbes
What are the sterilising agents for potable water ?
Sterilising agents used for potable water include chlorine, ozone 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 through 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 waste water produced and how is it treated ?
• Urban lifestyles and industrial processes produce large amounts of waste water that require treatment before being released into the environment.
• Sewage and agricultural waste water require removal of 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 ?
Sewage treatment includes:
- screening and grit removal
- sedimentation to produce sewage sludge and effluent anaerobic digestion of sewage sludge aerobic biological treatment of effluent
What do new methods of mining avoid in terms of disadvantages of traditional mining ?
Avoids the disadvantages of traditional mining methods of digging, moving and disposing of large amounts of rock
What is phytomining?
Phytomining 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 phtomining 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 (LCAs) 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 impacts.
What are the adv and disadvantages of recycling ?
Advantages of recycling: less acid rain (pollution) metal ore reserves last longer / conserved energy for extraction saved less mining / quarrying less waste less landfill creates local employment
Disadvantages of recycling; collection problems transport problems/ cost of transport difficult to separate metal from appliances/sort
