It seems strange that water should be such a scarce resource when our planet is drenched in 326 million trillion gallons of the stuff. But it turns out that less than one-half of 1 percent of it is drinkable. Out of the rest, 98 percent is oceanic salt water and 1.5 percent remains locked up in icecaps and glaciers. The stark irony of Samuel Coleridge’s immortal line “Water, water, everywhere / Nor any drop to drink” is manifest each year in coastal disasters around the world, like Hurricane Katrina, the 2004 Indonesian tsunami and the 2010 Haiti earthquake, as people within sight of entire oceans are threatened with dehydration.
Between droughts, natural disasters and the large-scale redistribution of moisture threatened by climate change, the need for new sources of potable water grows with each passing day. Each year, the global population swells to another 85 million people, but worldwide demand for freshwater increases at twice the rate of population growth, doubling every 20 years or so [sources:OECD, UNDP]. Throughout the world, our most vital resource is under stress from pollution, dam construction, wetland and riparian ecosystem destruction, and depletion of groundwater aquifers, with poor and marginalised populations getting the worst
One in 10 people worldwide lacks regular access to safe drinking water. In an effort to tackle this most basic humanitarian problem, engineers around the globe have developed a wide array of devices, large and small, that generate clean water. Each year, a slew of innovations aim to make the process easier, cheaper and more portable, as well as produce a yield high enough to make a real impact for some of the 663 million people who suffer from water shortages. Solutions range from using condensation methods to pull water from thin air, turning salty seawater into fresh water, or distributing UV light purification chips affordable enough for people to use at home. Only a few of these technologies are working outside the lab, but the ones that do have so far generated billions of gallons of clean water.
Even though we have these technologies, not all the technologies are financially feasible not only for developing countries even for the developed nations.
In this article, we have tried to list down some of the cheap water cleaning processes which are promising and implemented in some of the places
Going on to the first one :
Developed by a team of researchers at Alexandria University in Egypt, the procedure uses a desalination technique called pervaporation to remove the salt from sea water and make it drinkable. Specially made synthetic membranes are used to filter out large salt particles and impurities so they can be evaporated away, and then the rest is heated up, vaporised, and condensed back into clean water.
Crucially, the membranes can be made in any lab using cheap materials that are available locally, and the vaporisation part of the process doesn’t require any electricity. This means the new method is both inexpensive and suitable for areas without a regular power supply – both factors that are very important for developing countries.
The technique not only desalinates the seawater, it’s capable of removing sewage and dirt from it too. The researchers combined expertise in oceanography, chemical engineering, agricultural engineering and biosystems engineering to come up with the solution, and their work has now been published in the journal Water Science and Technology.
The technology implemented in the study is much better than reverse osmosis, the technology currently used in Egypt and most of the countries in the Middle East and North Africa,” Helmy El-Zanfaly, a professor of water contamination at Egypt’s National Research Centre, told Scidev.net. “It can effectively desalinate water with high concentration of salt like that of the Red Sea, where desalination costs more and yields less.”
Unfortunately for those who are waiting for this type of technology, a lot of work is required before it can be put into action: the academics working on the project have to set up a pilot test that proves their theories correct on a large scale. There’s also the issue of how to deal with the waste produced from the process.
What’s certain is that a new procedure like this could have a huge impact on the lives of millions of people – according to Water.org, some 750 million people across the globe don’t have access to clean drinking water, a problem that’s responsible for around 840,000 deaths every year – more than the entire population of San Francisco
With freshwater resources dwindling in many regions of the world, water desalination is proving to be a viable solution, especially in countries with mainly coastal populations. Today, there are around 17,000 desalination plants in 120 countries are producing 66 million cubic metres of clean water, two-thirds of it for human consumption, 30% for industrial use and 3% for irrigation and about 200 million people already use desalinated water. China and India are likely to have massive water needs over the next 50 years.
Is Desalination: a solution of the future. Yes … But why?
So what’s water Desalination then?
Water Desalination is a technique which removes the salt from the salty or brackish water to make it drinkable.
We will not be wrong if we say currently this enables 1% of all the drinking water around the world. But this is not the end this is set to grow more as depletion of fresh water resources and droughts are driving the governments to implement this technology
About 40% of the world’s population today lives within 100 km of the sea. This means that, potentially, 2.4 billion people could get their drinking water from desalination. What’s more, salt water represents 97% of the total volume of water on our planet, which makes it an enormous natural reservoir – as yet unexploited – compared with just 3% of freshwater that is normally used to produce drinking water.
In addition to these demographic and environmental considerations, desalination in today’s circumstances is an economically viable response for industrialised countries as well as for water-deficient regions. In the space of just 10 years, its cost has halved thanks to continuous improvements in reverse osmosis.
Reverse osmosis technology has advanced in leaps and bounds in recent decades. It is a reliable industrial process that provides large-scale solutions for drinking-water needs. Reverse osmosis produces drinking water by pressurising seawater to force water molecules to cross a membrane that is impervious to the salt molecules in seawater. The resulting freshwater is collected, while the salt-saturated water is treated, diluted and released back into the natural marine environment.
The two levers that must be activated as a priority today, to combat tomorrow’s shortages, are better water management and the securing of supply to make the best use of the resources that do exist, where they exist.
AMBITIOUS PROJECTS IN MELBOURNE, BARCELONA, CHILE AND THE KINGDOM OF BAHRAIN
DESALINATION BY DEGRÉMONT
255 plants around the world
10 million people served
2.8 million m3 drinking water produced per day
Degrémont, a SUEZ ENVIRONNEMENT subsidiary, has designed technology that can produce freshwater from seawater. It offers original and efficient processes for each step in the treatment, paying special attention to purifying the water upstream of the reverse osmosis stage. Formed in 1939 and having set up its first facility on Ile de Houat in France in 1969, this SUEZ ENVIRONNEMENT subsidiary now operates 255 desalination plants and supplies drinking water to 10 million people around the world.
Australia, Spain, Chile and the countries of the Middle East have chosen desalination to keep up with their population growth and solve their water scarcity problems. It is therefore in these countries that Degrémont’s most ambitious projects can be found.
In Melbourne (Australia) Degrémont has just commissioned the largest desalination plant in the southern hemisphere, which also happens to be one of the biggest in the world. The plant produces 450,000 m3 of drinking water a day and meets the needs of one-third of the 4 million residents of the second-largest city in the country. Degrémont also operates the biggest desalination plant in Europe. Located in Barcelona and opened in 2009, this plant supplies drinking water to nearly 20% of the population of the Barcelona region – about 5 million people – producing 200,000 m3 of desalinated water a day. By way of comparison, it could by itself meet all the drinking water needs of a city the size of Lyon in France.
In Puerto Coloso, Degrémont operates the largest reverse-osmosis desalination plant in South America. The plant uses electricity generated by wind power and produces 45,000 m3 of drinking water a day. Since 2011, this SUEZ ENVIRONNEMENT subsidiary also operates the Al Dur desalination plant on the south-east coast of the Kingdom of Bahrain. The facility produces 218,000 m3 of drinking water a day and underwent a full year of testing to determine the correct pre-treatment parameters for the specific characteristics of the seawater in the region.
It is estimated that by 2030, 4 billion people will be short of freshwater. Developing desalination today, therefore, means securing the long-term supply of water for people around the world. In short: it’s a solution of the future.
Let’s Hope more and more improvements in technologies come and which in turn reduce the cost if production of drinking water so that water scarcity in the world is solved.