c10 - Flashcards
what is potable water
water which is safe to drink
how is potable water produced by the uk
Choosing appropriate source of fresh water.
Passing water through filter beds.
Sterilising (use chlorine).
how is potable water produced by the other countries
Desalination of sea water.
Using distillation.
Or reverse osmosis.
But needs LOTS of energy
how is waste water produced
1) Screening & grit removal
2) Sedimentation to produce sludge & effluent
3) Sludge digested anaerobically by specific bacteria
4) effluent digested aerobically by bacteria
what is sludge used for
Used for fertiliser
As natural gas
what is effluent used for
Released back into the environment
Sewage & Agricultural waste water
Remove organic matter & harmful microbes
Industrial waste water
Remove organic matter & harmful chemicals
how can water be sterilised
chloring
uv
reverse osmosis
what are 2 alternative ways of extracting metal
phytomining
bioleaching
what is Phytomining
Plants absorb metal
Burn to ash
Extract by electrolysing ash solution (dissolved in acid)
what is Bioleaching
Bacteria produce leachate solution
Extract by electrolysing solution
how to write an effective life cycle assesment
Extracting & processing raw materials -use of energy, water, some wastes
Extracting & processing raw materials- Hard to measure effects of pollutants produced
Use & operation during it’s lifetime
Disposal, transport & distribution
why arent some LCA not accurate
used in advertising
why do we recycle
limited resources
save energy
What does ‘reuse’ mean?
To use the same item again for the same function
what is the harber process
NH3 is cooled, liquefied & removed
H2 & N2 are recycled
conditions for the harber process
Fe catalyst
450 oC
200 atm
why do we use these certain conditions
If we decrease temp
Equilibrium will shift to right (increase yield)
Favouring exothermic, as it will oppose the change
BUT decreasing temp decreases rate
450oC is a compromise, to increase rate without massively decreasing yield
why do we have these conditions (pressure)
If we increase pressure
Equilibrium will shift to right (increasing yield)
Favouring side with less GAS particles, as it will oppose the change
BUT increasing pressure is dangerous
200 atm is a compromise
what do NPK fertilisers contain
N –nitrogen
P – phosphorous
K - potassium
what is ammonia used for
Ammonia is used to manufacture ammonium salts & nitric acid.
what is phosphate rock used for
Phosphate rock is obtained by mining. Treated with nitric acid to produce soluble salts.
what are potassium salts
Potassium chloride & potassium sulphate are obtained by mining.
how to make amonium sulfate industry
Different stages require different temperatures
V. expensive machinery and equipment used in continuous process
Reactants made form raw materials (sulfur, air, water)
Huge quantities made quickly
Continuous – reduces labour & running costs
how to make amonium sulfate lab
Room temperature for neutralisation, then Bunsen burner for evaporation
Cheap lab equipment used in batch process
Reactants purchased from supplier
Small quantities made slowly
Batch – labour intensive so running costs are high
what is corrosion
destruction of materials by chemical reactions
how is rusting prevented
keeping oxygen away
Applying a coating which acts as a barrier
Zinc to galvanise iron – sacrificial protection
types of coating
Greasing
Painting
Electroplating
Aluminium oxide
alloys
bronze - copper and tin
brass - Copper + zinc
steels
High carbon = brittle
Low carbon = softer
Iron, copper + other metals
stainless steel is resistant to corrosion
2 types of glass
Borosilicate glass
soda-lime glass
soda lime glass
Heat sand, sodium carbonate & limestone
Borosilicate glass
Sand & boron trioxide
Melts at a higher temperature
what are ceramics
Shape wet clay then put in furnace
whats a composite
made of 2 materials. A matrix/binder binds the fibres or fragments of materials together.
whats a hd polymer
Pipes, bottles, buckets
Strong, flexible, resists shattering, unreactive
Branched chains
LD-polymers
Carrier bags, bubble wrap
Flexible, unreactive, can be made into film
Unbranched chains
Thermosoftening
Melt when heated
Due to weak intermolecular forces
Thermosetting
Do not melt when heated
Due to strong crosslinks
amonia react with oxygen and water
nitric acid
ammonia react with nitric acid
amonium salts
why cant phosphate rocks be used
insoluable
PR nitric acid
phosphoric acid and calcium nitrate
PR sufluric acid
calcium sulfate
calcium ohosphate
singer superphosfate
pr phosphoric acid
calium phostphate
triple superphospfate
