using the recourses Flashcards
what is sustainable development
an approach to human and economic development that meets the needs of current generations without harming the lives of future generations
what shouldn’t we do that could affect the lives of future generations
use up all limited resources
damage the environment
increase global warming
how can we develop more sustainably and why isn’t this necessarily working
use more renewable recourse such as wood and not plastic
.to make the wood usable we need to use fossil fuels to manufacture etc
what do you have to do to some metals before melting them to recycling them
separating them out into their different elements
what is potable water
water that is safe to drink but not necessarily pure
what are the three criteria water has to meet in order to be considered potable
- levels of dissolved substances need to be low
- PH between 6.5 and 8.5
- no microorganisms in it
where can we get potable water from
fresh water
explain how we can get fresh water (where it forms and the positives and negatives)
- when it rains
collects as ground water (underground)
surface water (lakes, river) - easy to access, replaced frequently, can dry off as exposed to sun
what are the three steps to treat fresh water so it becomes potable
- take fresh water through a wire mesh to filter any big objects - twigs
- pass through bed of sand and gravel - filter any smaller solid parts
- sterilise it to kill any bacteria
what are the three ways is fresh water sterilised
- bubble through chlorine gas
- passing through ozone and ultraviolet light
what technique do people from countries with not much rain use to get potable water
desalination
what is desalination and what methods are used to complete this and why isn’t it that much of a good idea
extracting potable water from sea water
- uses distillation and reverse osmosis
- need a lot of energy and expensive
how is distillation and reverse osmosis used to gain potable water
distillation - turn into water vapour and condense (like at school)
reverse osmosis - salty water massed through a membrane only allowing water to pass through
what are the three main sources of waste water
domestic - household waste
agricultural - animal waste and nutrient run offs
industrial - factories that make or use chemicals
why must domestic and agricultural waste be treated before going into rivers or seas and what more is done to industrial waste
remove any organic matter, harmful microbes therefore preventing health risks
- requires extra steps to remove the chemicals
how does sewage treatment work
- screening the sewage - removing anything large - through a mesh
- let sewage sit in a settlement tank to allow sedimentation to occur (any solid part of sink to bottom) and lighter part will stay on top and then separate into two tanks
- break down organic matter - biological breakdown by microorganisms
affluent (liquid tank) will be under aerobic conditions
sludge (solid) will be under anaerobic conditions
some water may need extra sewage treatment to be able to become fresh water - why and how is this fixed
if there is toxic substances
adding extra chemicals or using ultraviolet rays
what is a life cycle assessment
analyse the different stages on a products life cycle in order to asses the impact it has on the environment
what are the four main stages of a life cycle assessment
- extracting and processing
- manufacturing and packing
- using
- disposing
how is extracting and processing raw materials be harmful to the environment
extracting is damaging to local environment - cutting down forests
- digging mines
processing indirectly damage environment
- huge energy required
- pollutant are released
how is manufacturing and packing materials harmful to the environment
- require a lot of energy
- release of pollution
- production of waste products
when assessing the impact of using a product what do we have to consider
how damaging it is during its lifetime
how long you are using the product for
how is disposing materials harmful to the environment
if in a landfill you are using space that could have been used for nature
chemicals might be released int surrounding ecosystems
if burning them it will release pollutants
what are some limitations of the life cycle assessment
- making products uses loads of steps and hard to quantify all of them
- difficult to asses the harm of each steps
- so complex and therefore be manipulated to deliberately support a particular company
define corrosion and give an example
the process at which metals slowly are broken down by reacting with substances in their environment
rusting = iron + oxygen —hydrated iron oxide (rust)
what are the conditions required for rusting to take place
- ## need iron, oxygen and water
what happens if iron is left long enough in the correct conditions
as it rusts on the top, the pieces brake off revealing new metal underneath, this then rusts and breaks down eventually breaking down the entire chunk of iron
what are the two methods of preventing metals from rusting
barrier methods and sacrifical methods
how do barrier methods of preventing rusting work and what are the barrier methods
preventing oxygen and water from coming into contact with the metal
- paint it
- oil it
- electroplating - use electrolysis in a thin metal
how do sacrificial methods of preventing rusting work
adding a more reactive metal to the iron so if it is exposed the more reactive metal will be oxidised
what are the names of the two alternative methods of extracting metals
phytomining and bioleaching