the resources (paper.2) Flashcards
what is a life cycle assessment?
The different stages in a products life’s cycle in order to assess its impact on the environment
what are the 4 main stages to the life cycle assessment?
- extracting and processing the raw materials
-manufacturing and packaging your product
-using your product
-the disposing of your product
what is the problem with extracting raw materials?
damages the local environment e.g by cutting down trees, digging of mines
what are the problems with the processing raw materials?
it can indirectly damage the local environment due to the huge amounts of energy that is required and lots of pollutants can be released
what are the problems with the manufacturing and packaging of products?
-energy use
-pollution e.g carbon monoxide, hydrogen chloride
-production of waste products (may be used as raw materials but usually useless)
what 2 things are looked at when assessing the impacts of using the product?
-how much damage the product does during its lifetime
-how long the product is used for
how are products disposed and what are the problems with this?
-landfill: takes up space that could have been uses for nature + energy used to transport these materials + chemicals may seep out into the surrounding ecosystem
-burning the waste: releases pollutants into the atmosphere
what are the limitations of life cycle assessments?
-making products involves loads of different steps meaning its almost impossible to quantify them and the harm of each step
-can be manipulated deliberately to support a company
what is potable water?
water that is safe to drink and often contains other dissolved substances
what are the 3 criterias that need to be met to classify water as potable?
-fairly low level of dissolved substances
-pH between 6.5-8.5
-contains no micro-organisms
where do you get potable water from?
-surface water e.g lakes, rivers or reservoirs
-ground water e.g aquifers (areas of permeable rock which trap water)
what are the benefits of using surface water?
-easy access
-gets replaced frequently by the rain
what are the problems with using surface water?
can dry up as it is exposed to the sun
what are the steps taken in order to treat water to insure it is safe to drink?
-take fresh water and pass it through a wire mesh (to filter out any big things)
-pass it through a bed of sand and gravel (filters out any other smaller solid bits)
-sterilise it (to kill any harmful microbes)
how do you sterilise fresh water?
-bubble chlorine gas through it
-exposing it to ozone or ultraviolet light
