C12 Flashcards
Natural resources
Resources forming without human input, from the earth, sea or air
Examples of natural resources
Cotton for clothing or oil for fuel
How to replace natural products
Natural products can be replaced using synthetic products or improved upon by man-made processes
E.g. of natural products replaced by synthetic products or improved upon by man-made processes
Rubber is a natural product that can be extrafted from the sap of a tree, however man-made polymers have now been made which can replace rubber in uses like tires
How does agriculture help with natural resources?
Agriculture provides conditions where natural resources can be enhanced for our needs e.g. the development of fertilisers have meant we can produce a high yield of crops
Renewable resources
Renewable resources reform at a similar fate to, or faster than, we use them.
Examples of renewable resources
Trees
Fresh water
Food
Finite resources
Not formed quickly enough to be considered replaceable
Examples or finite resources
Fossil fuels
Nuclear fuels e.g. uranium and plutonium
Minerals and metals found in ores in the earth are also non-renewable materials
Copper
What happens after finite resources have been extracted?
Many finite resources undergo man-made processes to provide fuels and materials necessary for modern life e.g. fractional distillation is used to produce usable products such as petrol from crude oil and metal ores are reduced to produce a pure metal
Risks of extracting finite resources
People have to balance the social, economic and environmental effects of extracting finite resources. For example, mining metal ores is good because useful products are made, bit is bad for the environment as it uses loads of energy, scars the landscape, produces lots of waste and destroys habitats.
How is sustainable development inhibited
Using and extracting resources can he unsustainable due to the amount of energy used and waste produced. Processing the resources into useful materials, such as glass or bricks, can be unsustainable too, as the processes often use energy made from finite resources
Extracting copper from low-grade ores(new methods)
Bioleaching
Phytomining
Bioleaching
Bacteria is used to convert copper compounds in the ore into solible copper compounds, separating out the copper from the ore in the process. The leachate(the solution produced by the process) contains copper ions, whoch can be extracted by electrolysis or displacement eith a more reactive metal e.g. scrap iron.
Phytomining
This involves growing plants in soil that contains copper. The plants can’t use or get rid of the copper so it gradually builds up in the leaves. The plants can be harvested, dried and burned in a furnace. The ash contains soluble copper compounds from which copper can be extracted by electrolysis or displacement using scrap iron.
Disadvantages of traditional methods of copper mining
They’re pretty damaging to the environment.
Disadvantages of new methods of copper mining
They’re slow, but these new methods of extraction have a much smaller impact
Why is recycling metals important?
Recycling metals often use less energy than is needed to mine and extract new metal, conserves the finite amount of each metal in the earth and cuts down on the amount of waste getting sent to landfill.
There is also less acid rain(pollution) and less landfill creates local employment
How are metals recycled?
Metals are usually recycled by melting the, and then casting them into the shape of the new product.
What does the amount of separation required for recyclable metals depend on?
Depending on what the metal will be used for after recycling and the properties required of the final product, the amount of separation required for recyclable metals can change. For example, waste steel and iron can be kept together as they can both be added to iron in a blast furnace to reduce the amount of iron required to be extracted from the iron ore
Glass recycling
Glass recycling can help sustainability by reducing the amount of energy needed to make new glass products, and also the amount of waste created when used glass is thrown away
Methods of glass recycling
1) Glass bottles can be re-used without re-shaping.
2) Other forms of glass can’t be reused so they’re recycled instead. Usually the glass is separated by colour and chemical composition before being recycled.
3) The glass is crushed and then melted to be reshaped for use in glass products such as
bottles or jars. It might also be used for a different ourpose like insulating glass wool for wall insulation in homes.
Plastic bag
Raw materials - crude oil
Manufacturing and packaging - The compounds needed to make the plastic are extracted from crude oil by fractional distillation, followed by cracking and then polymerisation. Waste is reduced as the other fractions of crude oil have other uses.
Using the product - Can be reused. Can be used for other things as well as shopping
Product disposal- Recyclable but not biodegradable, and will take up space in oandfill and pollute land
Paper bags
Raw materials - Timber
Manufacturing and packaging - Pulped timber is processed using lots of energy. Lots of waste is made.
Using the product - Usually only used once.
Product disposal - Biodegradable, non-toxic and can be recycled
Life cycle assessments - what they show
Even though plastic bags aren’t biodegradable, they take less energy to make and have a longer lifespan than paper bags, so may be less harmful to the environment
Problems with life cycle assessments
Effect of some pollutants harder to give a numerical value to.
Producing an LCA isn’t an objective method - takes into account the values of the person carrying out the assessment.
Allocating numerical values to pollutant effects is less straightforward
Selective LCAs can be written to deliberately give positive advertising to the claims of a company.
Potable water
Water that’s been treated or is naturally safe for humans to drink