Using Resources
combined science
- Created by: abbienoice
- Created on: 17-11-20 12:41
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- Using Resources
- life cycle assessments
- looks at every stage of a products life to assess the impact it would have on the environment
- problems
- the use of energy, some natural resources and the amount of certain types of waste produced by a product over a lifetime can be easily quantified. but the effect of some pollutants is harder to give a numerical value
- producing a life cycle assessment is not an objective method as it takes into account the values of the person carrying out the assessment - LCAs can be biased
- selective LCAs only show some of the impacts of a product on the environment can also be biased as they are written to deliberately support the claims of a company - to give them + advertising
- the use of energy, some natural resources and the amount of certain types of waste produced by a product over a lifetime can be easily quantified. but the effect of some pollutants is harder to give a numerical value
- getting the raw materials
- manufacture and packaging
- using the product
- product disposal
- getting the raw materials
- manufacture and packaging
- using the product
- product disposal
- products are often disposed of in landfill sites - takes up space an pollutes land and water
- energy is used to transport waste to landfill - causes pollutants to be released into the atmosphere
- products might be incinerated - causes air pollution
- the use of a product can damage the environment
- how long a product is used for or how many uses it gets is also a factor - products need lots of energy to produce but are used for a long time means less waste in the long run
- product disposal
- can use a lot of energy resources and can also cause pollution
- need to think about any waste products and how to dispose of them. the chemical reactions used to make compounds from their raw materials can produce waste products
- some waste can be turned into other useful chemicals
- using the product
- can damage the local environment and can result in pollution due to amount of energy needed
- often need to be processed to extract the desired materials - often needs large amount of energy
- manufacture and packaging
- products are often disposed of in landfill sites - takes up space an pollutes land and water
- energy is used to transport waste to landfill - causes pollutants to be released into the atmosphere
- products might be incinerated - causes air pollution
- getting the raw materials
- the use of a product can damage the environment
- how long a product is used for or how many uses it gets is also a factor - products need lots of energy to produce but are used for a long time means less waste in the long run
- product disposal
- can use a lot of energy resources and can also cause pollution
- need to think about any waste products and how to dispose of them. the chemical reactions used to make compounds from their raw materials can produce waste products
- some waste can be turned into other useful chemicals
- using the product
- can damage the local environment and can result in pollution due to amount of energy needed
- often need to be processed to extract the desired materials - often needs large amount of energy
- manufacture and packaging
- Potable water
- water you can drink
- not pure as it contains dissolved substances
- how its produced
- when it rains water is collected as surface water (lakes, rivers and reservoirs) or as groundwater (in rocks called aquifers that trap water underground)
- in the UK the source of fresh water depends on location - surface water dries up first so eg. in the south east most of the domestic water supply comes from groundwater
- in some very dry countries theres not enough surface or groundwater and instead seawater must be treated by desalination
- seawater can also be treated by processes that use membranes - like reverse osmosis
- the salty water is passed through a membrane that only allows water molecules to pass through
- both methods need lots of energy - very expensive and not practical for mass production
- both methods need lots of energy - very expensive and not practical for mass production
- seawater can also be treated by processes that use membranes - like reverse osmosis
- filtration - a wire mesh screens out large twigs etc. and then gravel and sand beds filter out any solid bits
- sterilisation - the water is sterilised to kill any harmful bacteria or microbes - can be done by bubbling chlorine gas through it or by using ozone or ultraviolet light
- when it rains water is collected as surface water (lakes, rivers and reservoirs) or as groundwater (in rocks called aquifers that trap water underground)
- waste water treatment
- sewage treatment:
- diagram*
- 1. the sewage is screened - removing any large bits of material as well as grit
- 2. then it stands in a settlement tank and undergoes sedimentation - the heavier suspend solids sink to the bottom to produce sludge while the lighter effluent floats to the top
- 3. the effluent in the tank is removed and treated by biological aerobic digestion - where air is pumped through the water to encourage aerobic bacteria to break down any organic matter
- 4. the sludge from the bottom of the tank is removed and transferred into large tanks - gets broken down by bacteria in a process called aerobic diestion
- 5. aerobic digestion breaks down the organic matter in the sludge, whilst releasing methane gas - the methane gas can be used as an energy source and the remaining digested waste can be used as fertiliser
- 6. for waste water containing toxic substances - might need to add chemicals, UV radiation or using membranes
- 5. aerobic digestion breaks down the organic matter in the sludge, whilst releasing methane gas - the methane gas can be used as an energy source and the remaining digested waste can be used as fertiliser
- 4. the sludge from the bottom of the tank is removed and transferred into large tanks - gets broken down by bacteria in a process called aerobic diestion
- 3. the effluent in the tank is removed and treated by biological aerobic digestion - where air is pumped through the water to encourage aerobic bacteria to break down any organic matter
- 2. then it stands in a settlement tank and undergoes sedimentation - the heavier suspend solids sink to the bottom to produce sludge while the lighter effluent floats to the top
- can be used as an alternative in areas where there's not much fresh water
- where it comes from
- when you flush water down the drains in your house it goes into the sewers and towards sewage treatment plants
- agricultural systems produce a lot of waste water including nutrient run-off from fields and slurry from animal farms
- sewage from domestic, industrial and agricultural sources have to be treated to remove any organic matter and harmful microbes before it can be put back into freshwater sources
- industrial processes also produce a lot of waste water that has to be collected and treated
- sewage treatment:
- natural resources
- includes anything that comes from the earth, sea and air - form without - human input
- can be replaced by synthetic products or improved upon by man-made processes
- agriculture provides conditions where natural resources can be enhanced for our needs
- some will run out:
- renewable resources
- reform at a similar rate to or faster than, we use them
- eg. fresh water and food
- finite (non-renewable) resources
- aren't formed quickly enough to be considered replaceable
- include fossil fuels and nuclear fuels such as uranium and plutonium , metals and minerals found in ores in the earth
- after they've been extracted, many finite resources undergo man-made processes to provide fuels and materials necessary for modern life
- renewable resources
- risks of extracting finite resources
- people have to balance social, economic and environmental effects
- reuse and recycling
- sustainable development
- an approach to development that takes account of the needs of present society while not damaging the lives of future generations
- using, processing and extracting resources can be unsustainable
- extracting - due to the amount of energy used and waste products produced
- processing - amount of energy used from finite resources
- one way of reducing finite resources is for people to use less
- we cant stop using them altogether but chemists can develop and adapt processes that lower amounts of finite resources and reduce damage to the environment
- copper ores
- copper is a finite resource
- to improve its sustainability you can extract it from low grade ores (ores without much copper)
- bioleaching
- bacteria are used to convert copper compounds in the ore into soluble copper compounds, separating out from the copper ore in the process
- the leachate (solution produced) contains copper ions which can be extracted
- bacteria are used to convert copper compounds in the ore into soluble copper compounds, separating out from the copper ore in the process
- phytomining
- this involves growing plants in soil that contain copper - plants cant use or get rid of it 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 which copper can be extracted by electrolysis or displacement
- this involves growing plants in soil that contain copper - plants cant use or get rid of it so it gradually builds up in the leaves
- traditional methods are damaging to the environment - the new methods have smaller impacts but they're slow
- bioleaching
- recycling metals
- mining and extracting metals takes lots of energy
- recycling metals uses much less energy - conserves the finite amount of each metal in the earth and cuts down amount of waste getting sent to landfill
- metals are usually recycled by melting them and then casting them into the shape of the new product
- depending on what the metal will be used for after recycling, the amount of separation required can change
- recycling glass
- reduces the amount of energy needed to make new glass products and amount of waste created when used glass is thrown away
- glass bottles can be reused without reshaping
- other forms of glass cant be reused so they're recycled instead - usually separated by colour and chemical composition before being recycled
- the glass is crushed and then melted to be reshaped for use
- sustainable development
- life cycle assessments
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