Random C10 Flashcards
What action helps to save on the large amount of energy required to mine and extract them?
Recycling metals
How are waste metals recycled?
Melted down and recast into new products
How is Glass Recycled?
Waste glass is separated by colour and chemical composition, to then be crushed and melted for reshaping
What else can happen with glass bottles instead of recycling?
Reusing
What is potable water?
Safe to drink (filtered)
Is potable water chemically pure?
No (contains low levels of dissolved salts and microbes)
Ground water comes from underground rocks and must be treated by …?
Filtering and sterilising
Salt water comes from sea water and must be treated by…?
Desalination
Waste water comes from sewage treatment and agricultural systems, does this require a lot of treatment?
Yes
What is the first step in treating ground water?
Removing large organic matter
How is large organic matter removed in treating ground water?
Filterbeds (dissolve the insoluble solids)
After filterbeds are used, what is used to remove the smaller organic matter (in treating ground water)?
Sand and gravel filtration
After sand and gravel, what is done to treat ground water?
Sterilisation
How does sterilisation treat ground water?
Kills harmful microbes
What is used in the sterilisation of ground water?
Chlorine, ozone or UV (light)
What are 2 different methods of Desalination?
•distillation
•Reverse osmosis
What type of water is treated with desalination?
Salt water
What is the process of distillation (for desalination)
Boil the water to separate it from dissolved salts
What is the process of reverse osmosis (for desalination)
Pressure applied to pass water though a partially permeable membrane which filters contaminants
What is the issue with both distillation and reverse osmosis for desalination?
Use lost of energy
What is the stages of treating waste water?
1)Screening
2)Sedimentation
3)aerobic digestion of organic matter
4)anaerobic digestion of organic matter
In treating waste water, what happens in screening?
Organic insoluble matter (e.g. dead/ decaying animal+ plants) is removed
In treating waste water, what happens in sedimentation?
Sludge sinks to the bottom while effluent remains
In treating waste water, what happens to the effluent after sedimentation?
Digested aerobically -removed organic matter and harmful microbes
In treating waste water, what happens to the sludge after sedimentation?
Dried and Digested anaerobically
Once effluent is aerobically digested what can happen to it?
Released back to environment
Once sludge is anaerobically digested, what can it be used for?
Fertilisation
