Grey water (water soiled by human activities such as showers, dishwashers, washing machines and kitchens) is an example of a waste that can be converted into a resource. The molecules that come from soaps are mainly carbon molecules with phosphatic and nitrogen compounds. Nitrogen (N) and phosphorus (P) found in grey water are two elements required by plants as well as certain bacteria and fungi to develop. In ordfer tocleaen grey water, the solution is, therefore, to slow it down sufficiently to allow organisms to incorporate N and P before they scatter into the ecosystem. This practice also makes it possible to extract nitrogen and phosphate molecules, often called pollutants, from water in order to purify water, it is called phyto-purification. Once integrated into a fast-recycling nutrient cycle, grey water has the potential to increase ecosystem productivity. At La Evidencia, we will benefit from the presence of nutrients in grey water for the production of bananas in «Banana Circle». A “Banana Circle” is a row of bananas that are circled around a pile of organic matter.
The pile of organic matter is kept wet by a stream of grey water. During the decomposition of the pile of organic matter by the microorganisms, the mineralized nutrients are released and percolate by gravity downwards. The roots (rhizomes) of bananas, which require a lot of water and nutrients, recover all the mineralized nutrients during decomposition.
Several “Banana Circle” will be arranged sequentially and connected to ensure that the organic matter in the pile is never immersed in grey water. At the end of the series of «Banana Circle», we find purified water.
