Drinking water from the sea: here is the sustainable desalination

Dec 29, 2016 | written by:

The international concern about the availability of water resources is increasingly urgent. Even today, according to the recent study 'Savinglives, emergency water' published by Oxfam, 748 million people worldwide, about 1 in 8, are living without access to clean water. Not only that, 2.5 billion have no sanitation services due to wars and natural disasters. A problem that manifests its gravity and that stirs the geopolitical balance globally.

There are many technologies for water desalination, for the transformation of water collected from the seas in drinking resource, that is under research and development at the time. Parallel consultations are under way for the promotion of international cooperation: last in order of time that between Saudi Arabia and Japan in the energy infrastructure sector for water desalination.

To demonstrate the relevance of the potential effects of the problem, is indicative report that from 2015 to date, China has engaged in 121 desalination projects, acting on more than one million tons of seawater a day. The scarcity of water resources greatly affects the country, one of the 12 with more water problems in the world. Recent data shows that in over 300 cities there is no water and many coastal cities have no access to drinking water; a situation, the latter, which is likely to create in 2030 a water deficit of 21.4 billion cubic meters.

A solution that looks very promising is the time trial stage in the South Australian desert. The Anglo-Australian company Sundrop Farms, based in Port Augusta, is producing 17,000 tons of tomatoes a year in what would seem a science fiction greenhouse. Without land, without pesticides and in one of the driest parts of the continent: this is the scenario of a flourishing agricultural production seems improbable, if not utopian. But thanks to the ocean two kilometers away and the practice of agriculture hydroponics, the 180 thousand plants grow luxuriantly without herbicides and on a substrate of coconut husks.

All this is possible, and sustainable, just by installing a solar energy system for water desalination pumped from the Spencer Gulf. Fueling the set of devices is sunlight reflected by mirrors 23 thousand and then concentrated on a solar tower 115 meters high. The small plant in a cloudless day produces up to 39 megawatts of power.

In the United States the practice of desalination is not new, although only in 2015 was launched a project of MIT, the Massachusetts Institute of Technology, for the conversion of salt water into drinking water thanks to a device powered by solar energy. In Europe and North Africa make progress: Israel currently meets 40% of its water needs through water from the Mediterranean Sea covered in plants for desalination.

The goal is: sustainable water for all!

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