Phosphorus recovery from sewage sludge ash through an electrodialytic process

Paula Guedes; Nazaré Couto; Lisbeth M Ottosen; Alexandra B Ribeiro

doi:10.1016/j.wasman.2014.02.021

Phosphorus recovery from sewage sludge ash through an electrodialytic process

Waste Manag. 2014 May;34(5):886-92. doi: 10.1016/j.wasman.2014.02.021. Epub 2014 Mar 18.

Authors

Paula Guedes¹, Nazaré Couto², Lisbeth M Ottosen³, Alexandra B Ribeiro⁴

Affiliations

¹ 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.
² 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.
³ Department of Civil Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark.
⁴ CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.

PMID: 24656469
DOI: 10.1016/j.wasman.2014.02.021

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.

Keywords: Electrodialytic separation; Heavy metals; Phosphorus; Sewage sludge ash.

Publication types

Evaluation Study
Research Support, Non-U.S. Gov't

MeSH terms

Dialysis
Electrochemical Techniques*
Phosphorus / chemistry*
Sewage / chemistry*
Waste Disposal, Fluid / methods*
Water Pollutants, Chemical / chemistry*
Water Pollution, Chemical / prevention & control*

Substances

Sewage
Water Pollutants, Chemical
Phosphorus