c10 : using resources

What is sustainable development?

sustainable development is development that meets the needs of current generations without compromising the ability for future generations to meet their own needs

In the Uk, how is portable water produced

portable 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 portable water?

Sterilising agents used for portable 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?

reverse osmosis is when 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 or 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 treatments 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 metals 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 Assessment (LCAs) are carried out 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 material d by chemical reactions with the substance in the environment, e.g. rusting

Corrosion can be prevented by applying a coasting that acts as a barrier, such as greasing, painting or electroplating. These methods stop that air or water coming into contact with the metal

Describe the sacrificial protection

Some coating re reactive nd may contain corrosion inhibitors or a more reactive metal.

If two metals are in contact that 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 use of bronze, brass, gold and silver and copper and zinc, aluminium- magnesium and steels

Bronze - an alloy of copper and tin, used for making statues and decorative objects

Brass - an alloy of copper and zinc used for producing water taps and door fittings

Gold used as jewellery is usually an allow with silver, copper and zinc (the proportion of gold in the allow is measured in carats, with pure gold being 24 carat, e.g. 18 carat gold is 75% gold)

How are the properties of powers determined?

The properties of polymers depend on Whatt 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 polymers molecules are linked to each other by strong cross-links. Thermosoftening polymers softening 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 pf thee glass we use is soda-lime glass, made by heating a mixture of and, sodium carbonate and limestone. Borosilicate glass, made from sand and boron trioxide, melts at higher temperatures then soda-lime glass

How are clay ceramics made?

Clau ceramics, including pottery and bricks, are made by shaping wet clay and then heating in a furnace

How are composites formed?

Fibres or fragments of one material ( reinforcement) are surrounded by a binder/matrix material that holds these fibres/fragments together.

E.g. fibreglass - glass fibres bound together in a polymer, used for making storage tanks

How are compounds of nitrogen, phosphorus and potassium used?

Compounds of nitrogen, phosphorus and potassium are used as fertilisers to improve agricultural productivity. NPK fertilisers contain compounds of all three elements

How id the industrial production of NPK fertilisers achieved?

Ammonia can be used to manufacture ammonium salts. The ammonium sulfate, phosphate, and nitrate can be produced by reaction of ammonia with the requisite acid.

How is the phosphate rock utilised in the production of fertilisers?

• phosphate rock is reacted with the nitric acid to produce phosphoric acid and calcium nitrate

• Phosphate rock can be reacted with sulfúrico acid to produce a mixture of calcium phosphate and calcium sulfate

• Phosphate rock can be reacted with phosphoric acid t produce calcium phosphate