14. Could wastewater be used to solve water shortages?
In the United Nations Report on the Development of Water Resources in the World, entitled “Wastewater – The wasted resource”, whose presentation took place in the city of Durban, on 03-17-2017, on the occasion of the celebration of World Water Day, a series of approaches is listed regarding the conversion of wastewater into freshwater.
It is good to remember the difference between fresh water and drinking water. The first case refers to non-salty water, suitable for agricultural and industrial use. Drinking water, on the other hand, is treated fresh water, suitable for human consumption.
UNESCO argues that “wastewater can be an invaluable resource in meeting the world’s growing demand for fresh water and various raw materials.”
The procedure described frames to achieve the Sustainable Development Goal, SDG 6 Clean water and sanitation, “which aims to increase the reuse of water and reduce by half, by 2030, the amount of untreated wastewater.”
The aforementioned report also talks about “the collection, treatment and safe use of wastewater are the very basis of a circular economy, in which economic development and the sustainable use of resources are balanced. Reclaimed water is a very little exploited resource that can be reused multiple times. ”
It is important to note that “Wastewater is generally used for agricultural irrigation. Around the world there are at least 50 countries that use them for this purpose, which represents approximately 10% of the total area of cultivated land. However, the data available in this regard is still incomplete in many regions of the world, particularly Africa ”.
According to Unesco, the practice of reusing sewage “can lead to health problems when the water contains pathogenic germs that can contaminate crops. Hence the challenge of moving from uncontrolled irrigation to a planned and safe use of water intended for irrigation, as Jordan has been doing since 1977 until 90% of its treated wastewater is used. to irrigate crops. In Israel, treated wastewater already accounts for almost half of all water used for irrigation. ”
There is a very important point to take into account, and that is that “treated wastewater can also serve to increase the supply of drinking water, but this practice is still very limited. In Windhoek, the capital of Namibia, this procedure has been used since 1969. With a view to counteracting recurring water shortages. That city has created facilities to treat up to 35% of wastewater, which is then used to increase drinking water reserves. The people of Singapore and San Diego (United States) also safely drink recycled water. ”
It is interesting to know that “on the International Space Station, astronauts continue to use the same recycled water since 2001.”