title: Phosphorus recovery from sewage sludge ash through an electrodialytic process.
abstract: The electrodialytic separation process (ED) was applied to sewage sludge ash (SSA) aiming at phosphorus (P) recovery. As the SSA may have high heavy metals contents, their removal was also assessed. Two SSA were sampled, one immediately after incineration (SA) and the other from an open deposit (SB). Both samples were ED treated as stirred suspensions in sulphuric acid for 3, 7 and 14 days. After 14 days, phosphorus was mainly mobilized towards the anode end (approx. 60% in the SA and 70% in the SB), whereas heavy metals mainly electromigrated towards the cathode end. The anolyte presented a composition of 98% of P, mainly as orthophosphate, and 2% of heavy metals. The highest heavy metal removal was achieved for Cu (ca. 80%) and the lowest for Pb and Fe (between 4% and 6%). The ED showed to be a viable method for phosphorus recovery from SSA, as it promotes the separation of P from the heavy metals.
authors.affiliation: CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Department of Civil Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark. Electronic address: p.guedes@campus.fct.unl.pt.
authors.forename: Paula
authors.initials: P
authors.lastname: Guedes
authors.affiliation: CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Department of Civil Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark.
authors.forename: Nazaré
authors.initials: N
authors.lastname: Couto
authors.affiliation: Department of Civil Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark.
authors.forename: Lisbeth M
authors.initials: LM
authors.lastname: Ottosen
authors.affiliation: CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Alexandra B
authors.initials: AB
authors.lastname: Ribeiro
mesh_terms: D003956:Dialysis; D055664:Electrochemical Techniques; D010758:Phosphorus / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014877:Water Pollution, Chemical / Q000517:prevention & control*
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical; D010758:Phosphorus
keywords: Electrodialytic separation; Heavy metals; Phosphorus; Sewage sludge ash