C14 - The Earth's Resources Flashcards
1
Q
How can water be made fit to drink?
A
- Pass through filter beds to remove solids.
- Adding chlorine.
- Passing through ultra-violet light.
2
Q
How is waste water treated?
A
- Screened to remove large solids.
- Sedimented to remove sewage sludge, which is used as fertilizer.
- Water bubbled to break down microorganisms.
3
Q
How is copper extracted from copper-rich ores?
A
Smelting, then electrolysis is used to purify the copper by adding sulfuric acid.
4
Q
How is copper extracted from lower grade copper ores?
A
- Phytomining, where plants absorb copper ions before being burnt. Sulfuric acid is added to the ash to “leach” the copper out.
- Bioleaching, where bacteria feed on the copper, and a solution of copper ions can be obtained.
In both of these methods, electrolysis is then used to purify the solution.
5
Q
What is an LCA?
A
A Life Cycle Assessment assesses the environmental impacts of products, processes or services, by analyzing each of the stages of the life cycle - extraction, manufacture, use, maintenance, and recycle.
