Resources Flashcards
Sustainable / renewable resources
Meets the needs of current generations without compromising the ability of future generations to meet their own needs
What is potable water?
Water which is safe for human consumption, and which has sufficiently low levels of dissolved salts and microbes and a pH between 7.5 and 8.5
How is most potable water in the UK produced?
- Choosing source
- Passing through filter beds
- Sterilisation
How is water made potable? (detailed)
- Filter out big things (eg. Sticks) with a wire mesh
- Use sand beds and gravel to filter out finer particles
- Sterilise it (through bubbling chlorine through it, exposing it to UV light or exposing it to ozone)
Benefits and negatives of surface water
- Easy to access
- Replenished frequently
- Can dry up in sun
Desalination
- Used to extract potable water from sea-water
- Unlimited because it is from the sea
- However requires huge amounts of energy, lots of energy
- Distillation involves simple distillation but larger quantities
- Collect water vapour and condense it to produce potable water
- Reverse osmosis involves salty water being passed through a membrane
- Only allows water molecules to pass through, so all the larger ions and molecules are trapped, leaving pure and distilled water behind for drinking because it is POTABLE
How to treat sewage water?
- Screening and Grit removal
- Sedimentation to produce sewage sludge and effluent
- Anaerobic Digestion of sewage sludge
- Aerobic digestion of effluent (biological treatment)
COpper
Copper stores are running out, so we have to extract copper from low-grade ores
Phytomining, bioleaching
They avoid mining, digging and moving or disposing of large rock
What is Phytomining?
Phytomining uses plants to absorb metal compounds through their routes
The plants are then harvested and burned to produce ash containing the metal compounds
High concentration of metal ion in tissue, thus also in the ash
Bioleaching
Uses bacteria to produce LEACHATE solutions that contain metal compounds
Bacteria is mixed with the low-grade ore
Bacteria carries out a chemical reaction
How is copper etractedf?
After bioleaching or phytomining, the leachate/ product needs to have the metal extracted from it
Copper can be displaced from the ore using iron
Iron is more reactive than copper so can be displaced
Scrap ion is used because it is cheap
Copper can also be extracted by electrolysis
Key points about bioleaching and phytomining
Both of these allow us to economically extract metals from low-grade ores
They do not require digging or transporting of rock
What is the Haber process
The production of AMMONIA
Which can be used for FARMING
Equation of Haber Process
N2 + 3H2 2NH3
Sources of hydrogen and Nitrogen?
- Hydrogen from the AIR
- Nitrogen from reacting METHANE with STEAM