Creation of a "multimedia animation" for the public communication of INRAE’s national REUSE network

Despite major disparities between countries, agriculture is the main user, in terms of volume, of the water we take from the natural environment. However, for several decades now, in many regions of the world, and in particular in Europe and throughout the Mediterranean basin, we have been witnessing an increase in the pressure on water resources and, if not a decline in its quality, at least the presence of new contaminants as a result of human activities and climate change. In addition to the 6 million ha irrigated with controlled wastewater, about 10% of the world’s irrigated areas (30 million ha) receive uncontrolled wastewater, discharged into the environment without treatment or with only cursory treatment, whether this is due to conscious or unconscious practices, and is referred to as indirect or informal "REUSE". REUSE consists of substituting water taken from the natural environment with water that has been used for the first time and then treated for a new use. It is part of the so-called non-conventional water use solutions and is part of the circular economy principles applied to the water cycle, potentially also including the nutrient cycle. In the light of current changes, we must now take up this issue to assess its relevance, performance and impacts, and integrate any other alternatives (including source separation approaches).

Attractive and with great potential at the interface of major issues related to the fight against climate change (energy production, recycling of materials, closing of cycles, etc.), the use of REUSE and its implementation come up against many barriers that require significant research efforts. The challenges are multiple and are as much a matter of human and social sciences as of experimental and exact sciences.