Conception d'un dispositif de traitement d'eau captée depuis l'atmosphère

The worldwide water shortage currently experienced has led researchers to develop new ways to provide drinking water to the populations in need. This is how atmospheric water har-vesting process came to life, enabling people to have access to water even in remote areas. Nanoporous sponges are one of the materials designed for this purpose and are the material considered here. However, no research has been made relative to the mineral content or the bacteriological contamination of the produced water. A disinfection system has to be designed, specifically for populations living in remote areas with little access to electricity. The mineral content of nanoporous sponges soaked in water has been measured, raising an alarm on exceptionally high sodium carbonate content in the water, at levels impacting its taste and properties -the pH rises over 11. To limit this occurrence, a washing protocol has been devised to re-move most of the contamination which is caused by a pH control agent during the sponges’ synthesis. The results have also confirmed that once this agent has been removed, the water is nearly pure, all minerals being either at or below detection range. Finally, using ultraviolet light emitting diodes (LEDs) was elected to be the most effective disinfection method in remote areas due to low power consumption, absence of consumables and easiness of the maintenance. Simulations have been run on COMSOL to design a dis-infection system and determine the ideal values of its parameters in the case of a plug flow modelling of the water. It has been established there are ideal values for the radius, water flow and number of diodes that promote both biocidal effectiveness and energy economies. For LEDs emitting at 11,5mW, an optimal radius is 6cm in a configuration made up of 2 rings of 3 LEDs each. This is not affected by the value of the water flow but, for the system to be respectful of the laws regulating potable water, this flow has to be limited to 1 L/h. Lab experiments have yet to be realized to confirm those simulations results and for a complete system to make the water drinkable, a remineralization setup must be designed as well.