Using Earths Resources - C10 Flashcards
What do human’s use the Earth resource’s for?
To provide warmth, shelter, food
and transport.
What do the natural resources, supplemented by agriculture, provide?
Food, timber, clothing and fuels.
What are finite resources from the Earth, oceans and atmosphere processed to do?
Provide energy and materials.
What is sustainable development?
Development that meets the needs of current generations without compromising the ability of future generations
to meet their own needs.
Examples of natural resources?
Cotton for clothing, oil for fuel
Example of natural products replaced by synthetic?
Rubber from tree sap is now man-made polymers.
What is a renewable resource?
Resources that reform at a similar rate or faster than we use them.
What is a finite resource?
Resources that are not formed quickly enough to be considered replaceable.
For humans what should drinking water be like?
Have sufficiently low levels of dissolved salts and microbes.
What is potable water?
Water that is safe to drink.
Why is potable water not pure water in the chemical sense?
It contains dissolved substances.
What does the methods used to produce potable water depend on?
Available supplies of water and local conditions.
In the United Kingdom (UK), what is our water?
Rain that provides low levels of dissolved substances (fresh water) that collects in the ground and in lakes and rivers.
How do we produce potable water in the UK?
- choosing an appropriate source of fresh water: e.g in the south east because it’s warmer, most of the domestic water supply is from groundwater not surface water.
- passing the water through filter beds: a wire mesh screens out large twigs, and then gravel and sand beds filter out any other solid bits
- sterilising: kill any harmful microbes or bacteria. This is done by bubbling chlorine gas through it or by using ozone or ultraviolet light.
If supplies of fresh water are limited (dry countries), what is required?
Desalination of salty water or sea water.
How does desalination occur?
Distillation or reverse osmosis The salty water is passed through a membrane that only allows water molecules to pass through Ions and larger molecules are trapped by the membrane so separated from the water. This requires a lot of energy, so very expensive and not very practical.
What do urban lifestyles and industrial processes produce?
Large amounts of
waste water that require treatment before being released into the environment.
What does sewage and agricultural wast we water require?
Removal of organic matter and harmful microbes.
What may industrial waste water require?
Removal of organic matter and harmful chemicals.
Explain steps of sewage treatment
- screening and grit removal - large bits of material
- sedimentation to produce sewage sludge and effluent - in a settlement tank, the sludge sinks and the lighter effluent rises to the top.
- anaerobic digestion of sewage sludge - after the effluent is removed releasing methane gas in the process.
- aerobic biological treatment of effluent. air is pumped through the water to encourage aerobic bacteria digestion- to break down organic matter such as microbes.
Compare sewage treatment to fresh water
Sewage treatment requires more processes than treating fresh water but uses less energy than the desalination of water.
Why do we need alternative methods of extracting metals?
Copper ores are becoming scarce.
What are the new extraction methods and why?
Phytomining and bioleaching. They avoid digging, moving and disposing large amounts of rock (traditional mining methods) so less waste, less energy use, less destroyed habitats
Phytomining
Uses plants to absorb metal compounds in the soil. The plants are harvested and then burned to produce ash that contains metal compounds.
