desalination

what is desalination

process of removing salt and other minerals to provide fresh water

the process of desalination

multistage process

salt water intake

water forced through a semi permeable membrane at high pressure allowing reverse osmosis

this separates the water from the salt and other minerals

the system extracts the small % of freshwater from the seawater stream

leaves behind brine

what is desalination

process of removing salt and other minerals to provide fresh water

the process of desalination

multistage process

salt water intake

water forced through a semi permeable membrane at high pressure allowing reverse osmosis

this separates the water from the salt and other minerals

the system extracts the small % of freshwater from the seawater stream

leaves behind brine

what is Brine water

highly concentrated salt water

what countries use this method

Israel

USA

Saudi Arabia

pros water desalination

easy to build and operate

can achieve a high level of purification

not energy intensive

cons water desalination

chemicals used in the process e.g., chlorine and hydrochloric acid are dumped into the ocean

brine production - product of desalination - high concentration of salt into the ocean - ocean species may not be adapted to this

role of government and desalination

an expensive project that usually funded/ part funded by the government

water can become politicised

example of a TNC who is building a desalination plant

Veolia (France)

desalination and sustainability

burns fossil fuels

releases tonnes of co2

removing water may disrupt eco systems

brine has anti-scaling agents that harm the environment

why does desalination add co2 to the atmosphere

each plant requires a power stations

what are the benefits of Israel’s desalination project

reliable and predictable supply of water

produces 600 tonnes of portable water per hour

why might desalination be used more frequently in the future

the price of water is rising due to increased demand and shortages of supply

countries are increasingly looking toward the seas as their next source of water

cost of desalination plants

$1 million for small plant

$25 million for large plant

Israel evaluation points - sustainability

sustainable case as it the energy used is solar BUT this cannot be the case everywhere