It is now essential to save water and educate the younger generations to reduce water consumption. Farmers, industry and households, each must now pay attention to how it uses water, avoiding excessive or improper consumption .

Agriculture uses alone, via irrigation, 70% of the world water consumption. However, up to 40 to 60% of all this water is lost through leaks and evaporation. The margins for progresses are potentially huge in this field. However, achieving even a 13% economy of the agricultural water uses would save the equivalent of the world households consumption!



It is estimated that, in France, 15 to 25% of drinking water consumed in a building is lost due to leaks of the taps, toilets or plumbing in the common parts, not to mention the losses in the supply and distribution networks.
In addition to reducing consumption, another way to save water is to recycle. The same water can indeed be used several times for different uses, even for the same purpose. In developed countries, some industries already recycle their water circulating in closed circuit. The recycling of sewage is also possible. The Japanese, for example, have developed in areas where water is scarce a technique for recycling domestic water in buildings: they collect the wash water in tanks, treat them roughly and return it in the building for flushing toilets. That way, they reduce by half their water consumption.

• microfiltration : extension of the classical filtration ie that the water passes through a membrane that intercepts particles <1?m (such as colloids and bacteria);
• UV radiation (Ultraviolet): a high UV radiation intensity is sent to destroy micro-organisms and certain molecules;
• reverse osmosis : separate pure water from a water loaded with salts and organic materials (water is subjected toa high pressure mechanical making it pass through a semi-permeable membrane to retain the dissolved solids, organic matter, bacteria and viruses).

Example of recycling wastewater by microfiltration In Australia, a solution for water treatment and effluent has been proposed by Veolia in the region of Gerringong and Gerro, located 120 km away from Sydney. The technique suggested is microfiltration in order to be able to store 50 000 cubic meters of recycled water which can be used to:

• the re-use in the agriculture ;
• the production of 2 200 m³ /day ;
• expansion of local development and tourism (reduction of water pollution) .