Recovery of Phosphorus from Wastewater Treatment Systems

Phosphorus (P) is a non-renewable resource essential as fertilizer to ensure sufficient food production. The global, mineable P deposits are predicted to be
depleted within 60-130 years resulting in increased P and food prices thereby a
necessary reliance on P-recovery. Phosphorus in Danish wastewater is estimated to cover 15-25% of the Danish demand. Consequently, we propose a novel strategy for optimized P-recovery from wastewater by a detailed understanding of the P components, their availability and their flow in the wastewater treatment systems as well as applying specialized phosphate accumulating microorganisms to enhance capture of P components into the biomass. Hence, excess biomass is converted to bioenergy in digesters where release of stored P compounds and enzymatic hydrolysis of specific P compounds into the digester liquid will be stimulated. Highvalue P products will be concentrated and recovered from the P-rich liquid by a novel combination of ion-exchange, reactive crystallization and membrane processes, and the process will be optimized with respect to the overall recovery of different types of P products and the economy¬ of the process. Our team of experts on P-recovery from wastewater in Denmark, which represent both Danish and foreign universities as well as Danish consultant and municipal utilities will facilitate the transformation of Danish wastewater treatment plants to P-recovering units providing economic benefits for the municipal utilities and society. It will also support the competitiveness of the Danish wastewater industry on an increasing global marked.