PhosFarm project to recover phosphorus from agricultural residues
Recyclingportal.eu, October 11th
Stuttgart -Phosphorus is an important plant nutrient for agriculture; however, phosphate rock reserves are limited
In the EU-funded PhosFarm project, research and SME partners aim to make organic phosphorus from agricultural residues accessible as a resource for phosphate fertiliser salts. Using immobilised enzymes, organic phosphorus compounds are released from the organic matter and recovered as phosphate, says Fraunhofer IGB.
Besides non-renewable reserves, alternative phosphate resources include municipal wastewater and agricultural organic residues such as livestock manure or digestate from biogas plants. Although new technologies have already been developed for the recovery of dissolved inorganic phosphates in the liquid fractions of municipal and agricultural wastes, solid residues remain a largely untapped source for phosphorus in its organic form. In solid fractions, organic phosphorus bound in biochemical molecules such as phospholipids, nucleotides and nucleic acids offer a bountiful source of phosphorus.
These agricultural residues represent a huge additional reservoir for phosphate recovery: Annually, more than 1,800 million tonnes of manure are generated in the EU and the amount of digestion residues is still increasing. Especially in swine and poultry manure, up to 50 per cent of the overall phosphorus is present in the organic form. In the PhosFarm project, this organic residual matter is to be made accessible as a valuable phosphate resource. The project consortium coordinated by the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB wants to develop a process and realise a pilot plant that features a controlled enzymatic release of organically bound phosphate, enabling up to 90 per cent recovery of total phosphorus.