Extraction of Phosphorus from Sewage Sludge Ash—Influence of Process Variables on the Electrodialytic Process

Lisbeth M. Ottosen (), Gunvor M. Kirkelund, Pernille E. Jensen and Kristine B. Pedersen
Additional contact information
Lisbeth M. Ottosen: Department of Environment and Resource Engineering, DTU Sustain, Technical University of Denmark, 2800 Lyngby, Denmark
Gunvor M. Kirkelund: Department of Environment and Resource Engineering, DTU Sustain, Technical University of Denmark, 2800 Lyngby, Denmark
Pernille E. Jensen: Department of Environment and Resource Engineering, DTU Sustain, Technical University of Denmark, 2800 Lyngby, Denmark
Kristine B. Pedersen: Akvaplan-Niva AS, Fram Centre—High North Research Centre for Climate and the Environment, Hjalmar Johansens Gate 14, 9007 Tromsø, Norway

Sustainability, 2023, vol. 15, issue 18, 1-15

Abstract: Phosphorus is a critical, irreplaceable raw material, and developing methods to recover P from secondary sources such as sewage sludge ash (SSA) is crucial. Two-compartment electrodialytic extraction (2C-ED) is one method where an electric DC field is applied to extract P and separate heavy metals simultaneously. Several process parameters influence 2C-ED, and they influence each other mutually. This paper explores chemometrics modeling to give insight into the 2C-ED process and, specifically, optimization of the experimental parameters towards 80% P extraction. A projections-to-latent-structures model was constructed based on new 2C-ED experiments conducted with one SSA type. The model was stable (high correlation factor and predictive power). Variable importance in the projection (VIP) plots showed that the influence of the variables was in the order: current > duration > L:S ratio > stirring velocity > dispersion solution (weak acid or distilled water). Contour plots were used for exploring different P extraction strategies. For example, more P mass per unit current was extracted at an L:S ratio of 7 compared to L:S 14. This shows that treating a thicker SSA suspension is preferable to optimize the current efficiency. The chemometric model proved valuable for optimizing the 2C-ED process and future scale-up.

Keywords: phosphorus; heavy metals; electrodialysis; projections to latent structures; extraction (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/15/18/13953/pdf (application/pdf)
https://www.mdpi.com/2071-1050/15/18/13953/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:15:y:2023:i:18:p:13953-:d:1243857

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().