Using Resources Flashcards
(36 cards)
New ways of extracting copper?
•From low grade ores- bioleaching
•From contaminated land- phytomining
What is desalination?
How potable water is produced from sea water which has high levels of dissolved minerals
When fresh water supplies are limited how can we get water?
- Seawater desalinated
-Reverse osmosis
Other than bioleaching and phytomining how can copper be obtained?
Displacement using scrap iron or from solutions of copper salt by electrolysis
What happens in obtaining copper from copper salt by electrolysis?
Positive copper ions move towards negative electrode and forn pure copper
What is phytominig?
-Method, plants to absorb copper
-Plants grow, absorb+store copper
-Plants burned, ash contains copper in large quantities
Why does excessive mining mean for copper?
We are running out of it, have new ways to extract from ores with less copper
2 steps of sewage treatment?
1)Screened and grit removed by passing through a mesh
2)Sedimentation, produces sewage sludge and affluent
What happens to the sewage sludge?
Anaerobic bacteria digestion of sludge, in absence of oxygen bacteria produces biogas, burned for electric, at the end sludge used as fertilisers
What happens to the effluent?
Air bubbled through it as contains harmful microorganisms, allows aerobic bacteria to multiply in presence of oxygen, bacteria digest harmful microorganisms
What happens to effluent at the end?
Discharges into seas/rivers
What happens to sewage sludge at the end?
Can be used as fertilisers for farming
How does desalination happen?
By distillation
Steps of desalination (distillation)?
~Seawater boiled, produce steam
~Steam cools and condenses
~Produces pure water
What does water contain that needs to be at low levels to be safe?
Microorganisms and dissolved salts
What is desalinated water?
Salt water that has had all the dissolved salts removed to make pure water
What other ways can water be sterilised?
By ozone or ultraviolet
How can the taste of tap water be improved?
More dissolved substances can be passed through a filter containing carbon, silver and ion exchange resins
Why is the process of desalination and reverse osmosis expensive?
Require alot of energy
4 steps to producing potable water?
1)Fresh water from suitable source (lake/river) is collected
2)Passed through water bed, remove solid particles
3)Chlorine gas,kill microorganisms
4)Fluoride added, reduce 🦷 decay
Problems with LCA’s?
•Can’t be certain how damaging things are to environment
•Have to make estimates which aren’t always accurate
•Biased=support advertising claims
Why do metals, glass and plastics need to be used wisley, reused and recycled?
~Save 💰 + energy
~Reduce amount of waste
~Reduce environmental damage
~So natural resources not used when necessary
Why does metal, glass and plastics have a negative impact on environment?
Made from crude oil, finite resource, extracting raw material has negative environmental impact
How can plastic be reused?
Recycled to make fleece material
