Using Respurces Flashcards
Sustainable development
Sustainable development is an approach to human and economic development that meets the needs of the present generations,
without compromising the ability of future generations to meet their own needs.
two ways in which ‘extracting and processing the raw materials’ can damage the environment.
Cutting down trees
Digging of mines
Carbon dioxide production from energy use
Release of pollutants into the environment
Why is nitrogen important
Nitrogen is important to plants as it is required to make amino acids and hence proteins, which are essential for growth.
The main source of nitrogen in fertilisers is ammonia, which remember is made in the Haber process.
How is phosphate made
Phosphate can be mined from the ground as phosphate rock.
However, because the phosphate salts in the rock are insoluble, plants can’t use them as nutrients, and so they can’t be used directly in fertilisers.
Instead, we have to react the phosphate rocks with acids to produce soluble salts:
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 water is produced by…?
• choosing an appropriate source of fresh water
• passing the water through filter beds to remove any solids
• sterilising 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 wastewater 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.
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 is the main advantage and disadvantage of these methods?
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 LAs
Life Cycle Assessments (CAs) 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 advantages 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
What is corrosion and how is it prevented?
Corrosion is the destruction of materials by chemical reactions with substances in the environment, e.g. rusting.
Corrosion can be prevented by applying a coating that acts as a barrier, such as greasing, painting or electroplating. These methods stop the air or water coming into contact with the metal.
Describe the sacrificial protection
Some coatings are reactive and may contain corrosion inhibitors or a more reactive metal.
If two metals are in contact the more reactive metal will corrode instead of the less reactive one, e.g. zinc is used to galvanise iron and when scratched, provides sacrificial protection because zinc is more reactive than iron.
Describe the compounds and the uses of bronze
Bronze - an alloy of copper and tin, used for making statues and decorative objects.
How are the properties of polymers determined?
The properties of polymers depend on what monomers they are made from and the conditions under which they are made. For example, low density (LD) and high density (HD) poly(ethene) are produced from ethene, using different catalysts and reaction conditions.
Describe the structures of thermosoftening and thermosetting polymers
Thermosetting polymers do not melt on heating. The polymer molecules are linked to each other by strong cross-links. Thermosoftening polymers soften easily on heating and can then be remoulded, keeping the new shape on cooling. The polymer molecules are attracted to each other by weak intermolecular forces.
How is glass made?
Most of the glass we use is soda-lime glass, made by heating a mixture of sand, sodium carbonate and limestone. Borosilicate glass, made from sand and boron trioxide, melts at higher temperatures than soda-lime glass
