Nee.Prado.Fall2010

=Water Desalination=



Humanity is responsible for the largest consumption of natural resources on this planet. Fossil fuels, natural gas, food and even water. Out of all of these, water is probably the most important resource that we consume. It is necessary to our survival, as well as it composes over 70% of our bodies. All living things require water, not just humans. We can't go very long without drinking water. If we don't drink water we die, simple as that. As the human population increases so does the amount of water we must consume. Humans can only consume fresh water, salt water will only dehydrate us rather than keep us alive and nourish our body. With the demand for fresh water rising, scientists are trying to find ways to create more fresh water to take on the ever increasing populous. This is what gave way to the idea of desalination.

Silent Death in Darfur
Humanity is a very needy species. We cut down forests to build houses and level entire eco systems to build towns and cities. Once we've established a new civilization we roll in with the industry. Industrial plants are constantly burning fossil fuels for many different purposes, with power generation and factories to name a few. The other major component of any civilization is a freshwater supply. One way or another that town or city has a way of making fresh water for all of it's inhabitants. This was the case with the region of Darfur. Darfur is a small region located within Sudan. It had it's own freshwater rivers at one point, but our constant use of fossil fuels led to global warming which dried up the rivers. With most of it's freshwater supply depleted, the people of Darfur fought and killed each other over fresh water. They were willing to kill over that water because they know that it means life. Its the same thing with all species on this planet. Plants and animals both require fresh water in order to survive, were not the only ones. The genocide in Darfur is but a mere glimpse of what could be our future if there isn't enough water to go around. Water desalination is the process of removing salt from water, this can be done a few different ways.

Desalination Methods
Reverse Osmosis: Membrane processes use semi-permeable membranes and pressure to separate salts from water. Though the system is effective, one downside is it requires a rather large amount of energy.



Vacuum Distillation: A process which reduces the pressure on the liquid to less than it's vapor pressure, allowing easy evaporation. This is the more common of the two types of desalination due to it's less frivolous energy requirements.



Desalination Around The Globe
Since the constant need for Fresh water is a world wide epidemic, there are numerous desalination plants around the globe. These plants supply fresh water to their area, often times providing water to massive parts of entire countries.

Israel
This is the Hadera Desalination plant in Ashkelon, Israel. It produces 333,000 cubic meters of fresh water daily, and 33 million gallons every year. It supports 17% of the nations potable water supply.

This is the St Michael BWRO Desalination plant, Barbados. It produces 3,000 cubic meters of fresh water daily. The cost of the plant installation was 37.5 million. It provides water for 17% of the island. The wells that you see below are what contain and purify the brackish water that the plant takes in.This plant uses reverse osmosis to desalinate the water. ==

Environmental Impact
These desalination plants can be built with little or no environmental impact at all. Very few chemicals are used, and the plants are energy efficient. These plants are constructed to do purify water in the cleanliest way possible. Having very low levels in emission and other waste is causing an increase in their popularity as well as their need. Our population will continue to grow, and with it so will the number of desalination plants. There are currently more reverse osmosis plants in the world rather than the vacuum distillation type. As time goes on we will continue to develop new technologies which will help make a greener earth. We have to go green. if we don't start to now, our swiftly increasing population will see to damage our planet for all time. desalination is but a small step towards achieving a greener home.