Low-cost method of purifying water : Solar water disinfection

Nowadays the water consumption is a major problem: indeed it is a rare commodity that we consume over the top and which is endlessly wasted. The 98 percent of the wastewater in the world is not recycled, while millions of people do not still have access to drinking water and have to be satisfied with the polluted water from the rivers and the lakes. Yet there are very simple solutions to treat the used waters to reuse them for the daily consumption: the mainly used process is the treatment in water treatment plants, but several countries do not have it. So how to treat the water without any water treatment plant?

The lack of water treatment plants in the developing countries

Nowadays the developed countries do not have any problem to treat the soiled waters: indeed there are a lot of water treatment plants which fulfill this role, and enable to recycle the water to make it suitable for consumption again. However, numerous under-developed countries or developing do not have the opportunity to have a water treatment plant: so it becomes hard and even impossible to recycle the used waters, and the inhabitants do not have any other choice but use the water from the lakes and the rivers, whose cleanliness is often doubtful. The numerous pathogens in this water cause the most of the diseases in these countries.

Instructions for the solar disinfection

In front of the lack of water treatment plants, there is a very simple option to disinfect the water and make it drinkable: the solar disinfection, or SODIS. It consists in expose some water bottles in direct sunlight during at least six hours, to kill the germs which are responsible for the diarrheas and other diseases. However it is necessary to use only ethylene polyterephtalate, and strictly comply with the sunshine duration. This way, the developing countries can have drinking water.

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