T10 using resources

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

• choosing an appropriate source of fresh water • passing the water through filter beds to remove any solids • sterilising to kill microbes

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

distillation or by processes that use membranes such as reverse osmosis processes require large amounts of energy

sea water is passes through a membrane that only allows through the water molecules needs high pressure to push the water through the membrane the high pressure requires a lot of energy to produce

• urban lifestyles and industrial processes produce large amounts of waste water that requires 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

• screening and grit removal • sedimentation to produce sewage sludge and effluent • anaerobic digestion of sewage sludge • aerobic biological treatment of effluent

avoids the disadvantages of traditional mining methods of digging, moving and disposing of large amount of rock

uses plants to absorb metal compounds from the soil plants are harvested and then burnt to produce ash that contains the metal compounds

uses bacteria to produce leachate solutions that contain metal compounds

need less energy than traditional methods and can work on low concentration ores but are slow to carry out

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

reduction in use, reuse and recycling of materials by end users reduces the use of limited resources, energy consumption, waste and environmental impacts

less acid rain (pollution), metal ore reserves last longer, less landfill, creates employment collection problems, cost of transport, difficult to sort

destruction of chemical reactions with substances in the environment applying a coating that acts as a barrier, such as greasing, painting or electroplating - stop the air or water coming into contact with the metal

some coatings are reactive and may contain corrosion inhibitors or a more reactive metal if 2 metals are in contact, the more reactive metal will corrode instead of the less reactive one

alloys: bz - copper + tin, used for making statues, decorative objects br - copper + zinc, used for producing water taps and door fittings G - used as jewellery, alloy with silver, copper and zinc AM - low density, used in aerospace manufacturing S - iron that contain specific amounts of carbon and other metals. High carbon steel is strong but brittle. Low is softer and more easily shaped. Steel containing chromium and nickel (stainless steels) are hard and resistant to corrosion

depend on what monomers they are made from and the conditions under which they are made ex. low density and high density poly(ethene) are produced from ethene, using different catalysts and reaction conditions

sett - don’t melt on heating, polymer molecules are linked to each other by strong cross-links sof - soften easily on heating and can then be remoulded, keeping the new shape on cooling, polymer molecules are attracted to each other by weak intermolecular forces

most is soda-lime, 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

shaping wet clay and then heating in a furnace

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

• purified H2 and N2 gases are passed over Fe catalyst at high temperature (450C) and a high pressure (200 atm) • Fe speeds up the rate of reaction, so that a lower temperature could be used in the process • some of the hydrogen and nitrogen reacts to form ammonia N2 + 3H2 >< 2NH3 • reaction is reversible so ammonia breaks down again into nitrogen and hydrogen • on cooling, ammonia liquefies and is removed. Remaining hydrogen and nitrogen are recycled, no material wasted • ammonia is used for production of nitrogen-containing fertilisers

compromise between rate and the yield • reaction is exothermic, optimum temp is used (450), lower temp would give higher yield, but the rate of NH3 production would be too slow • pressure of 200 used, higher pressure would give higher yield, too expensive tho due to cost of energy to produce the high pressure