Comprendre les enjeux de l'agriculture

Essential for living organisms to function and indispensable for good yields in agriculture, phosphorus could disappear due to increasing use in farming.  “Recovering phosphorus from the wastewater in treatment plants, where it is abundant, to recycle it is a promising solution”, claims the IRSTEA website.
 Researchers at the OPAALE unit of IRSTEA have developed a new process. Present in large quantities in wastewater, the phosphorus contained in excrement and cleaning products causes eutrophication in aquatic environments. That is why treatment plants do indeed recover it, but without recycling it. The team of researchers at IRSTEA is working on developing a method to both extract phosphorus from wastewater and also reuse it, thus killing two birds with one stone: improving supplies and reducing water pollution. “We have developed a now patented biological process that makes it possible to extract phosphorus from sludge and reuse it directly as a fertiliser“, explains the researcher Marie-Line Daumer, Project Leader. “We encourage the development of two types of bacteria that are naturally present in the sludge: on the one hand, bacteria that produce acids; following the acidification of this environment, the bacteria that had captured the phosphorus during the treatment of the waste water react by releasing it… and, on the other hand, bacteria that destroy the metal complexes that had trapped the phosphorus. The phosphorus then finds itself in the liquid part of the sludge that we separate from the organic matter. In this way, depending on the type of sludge, up to 75% of the phosphorus can be dissolved. We can then recycle the phosphorus in the form of fertiliser and use the sludge for either methanization or spreading.”

Phos4You project web site:

Source: IRSTEA