authors |
Oliveira, V; Dias-Ferreira, C; Labrincha, J; Rocha, JL; Kirkelund, GM |
nationality |
International |
journal |
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY |
author keywords |
electrodialytic process; heavy metals; municipal solid waste; phosphorus; struvite |
keywords |
SEWAGE-SLUDGE; HEAVY-METALS; GASIFICATION; INCINERATION; EXTRACTION; ASH |
abstract |
BACKGROUND This work is focused on phosphorus (P) recovery from the anaerobically digested organic fraction of municipal solid waste (referred to as 'digestate') as a fertilizer. The main purpose was to propose and test modifications to the electrodialytic process that increase P extraction, improve the quality of the fertilizer by removing contaminants, and reduce hydraulic retention time to allow for smaller system footprints. Strategies tested were: (i) lowering the pH of the digestate suspension to <4.5 using the electrochemical reactions and enhance P solubilization from the waste; (ii) changing the configuration of the electrodialytic cell from three to two chambers; and (iii) stirring the sample to shorten the duration of the extraction. RESULTS Results show that the acidification of digestate by the electrochemical reactions was effective to enhance P extraction yield. Three-chamber electrodialytic experiments enabled the removal of heavy metals from the digestate, producing P-rich solutions with low metal concentrations. This resulted in the production of high-quality fertilizer which can be used for agricultural applications. The modification of the electrodialytic cell set-up from three- to two-chamber neither resulted in an increase of the P extraction yields, nor contributed to the removal of metals from the liquid phase of digestate. Reduction of the hydraulic retention time of electrodialytic extraction of P from 16 days to 9 days was attained by the use of stirring and by electrodialytic acidification. CONCLUSIONS An increase of P recovery was accomplished by modification of electrodialytic extraction, resulting in 90% of P being successfully extracted from the digestate and transformed into struvite. (c) 2019 Society of Chemical Industry |
publisher |
WILEY |
issn |
0268-2575 |
isbn |
1097-4660 |
year published |
2020 |
volume |
95 |
issue |
2 |
beginning page |
439 |
ending page |
449 |
digital object identifier (doi) |
10.1002/jctb.6037 |
web of science category |
Biotechnology & Applied Microbiology; Chemistry, Multidisciplinary; Engineering, Environmental; Engineering, Chemical |
subject category |
Biotechnology & Applied Microbiology; Chemistry; Engineering |
unique article identifier |
WOS:000505736200015
|