From waste to fertile technosol - The circular approach of the French research prject SITERRE
Résumé
Today, 50 % of the world population live in urban areas with an increasing evolution for the next decade. The city is an anthropological environment created by the man and for the man. For a very long time, the city was built to protect humans from wild animals. Nowadays, the city is a workplace, a hosting place, an entertainment place, a place of life in which the people must find all the necessary elements for his balance. The modern city presents a 'linear metabolism' that needs inputs (food, industrial products, raw materials) to develop all its activities with a lot of movement, circulation and transformation of material resources. A the end of the metabolize chain, the city produces waste that flow out of the urban system involving depletion of natural resources, pollution and toxic environments. Thus in the urban context, the balance, necessary for human physical and mental health, is a hot topic that must be deal with the environment and the nature. To preserve its viability, the urban system must evolve rapidly to a 'circular metabolism' by decreasing input consumption and by limiting economic and ecological costs for the transportation, treatment and landfill of waste materials.