Combined recovery of polyhydroxyalkanoates and reclaimed water in the mainstream of a WWTP for agro-food industrial wastewater valorisation by membrane bioreactor technology

Francesco Traina; Santo Fabio Corsino; Marco Capodici; Enrico Licitra; Gaetano Di Bella; Michele Torregrossa; Gaspare Viviani

doi:10.1016/j.jenvman.2023.119836

Combined recovery of polyhydroxyalkanoates and reclaimed water in the mainstream of a WWTP for agro-food industrial wastewater valorisation by membrane bioreactor technology

J Environ Manage. 2024 Feb:351:119836. doi: 10.1016/j.jenvman.2023.119836. Epub 2023 Dec 22.

Authors

Francesco Traina¹, Santo Fabio Corsino², Marco Capodici³, Enrico Licitra⁴, Gaetano Di Bella⁴, Michele Torregrossa³, Gaspare Viviani³

Affiliations

¹ Department of Engineering, University of Palermo, Viale Delle Scienze, Ed. 8, 90128, Palermo, Italy. Electronic address: francesco.traina02@unipa.it.
² Department of Engineering, University of Palermo, Viale Delle Scienze, Ed. 8, 90128, Palermo, Italy. Electronic address: santofabio.corsino@unipa.it.
³ Department of Engineering, University of Palermo, Viale Delle Scienze, Ed. 8, 90128, Palermo, Italy.
⁴ Facoltà di Ingegneria e Architettura, Università Degli Studi di Enna ''Kore'', Cittadella Universitaria, 94100, Enna, Italy.

PMID: 38141345
DOI: 10.1016/j.jenvman.2023.119836

Abstract

The present study investigated the combined production of reclaimed water for reuse purposes and polyhydroxyalkanoates (PHA) from an agro-food industrial wastewater. A pilot plant implementing a two-stage process for PHA production was studied. It consisted of a mainstream sequencing batch membrane bioreactor (SBMBR) in which selection of PHA-accumulating organisms and wastewater treatment were carried out in, and a side-stream fed-batch reactor (FBR) where the excess sludge from the SBMBR was used for PHA accumulation. The performance of the SBMBR was compared with that of a conventional sequencing batch reactor (SBR) treating the same wastewater under different food to microorganisms' ratios (F/M) ranging between 0.125 and 0.650 kgCOD kgTSS^-3 d^-1. The SBMBR enabled to obtain very high-quality effluent in compliance with the relevant national (Italy) and European regulations (Italian DM 185/03 and EU, 2020/741) in the field of wastewater reclamation, whereas the performances in the SBR collapsed at F/M higher than 0.50 kgCOD kgTSS^-1d^-1. A maximum intracellular storage of 45% (w/w) and a production yield of 0.63 gPHA L^-1h^-1 were achieved when the SBMBR system was operated with a F/M ratio close to 0.50 kgCOD kgTSS^-1d^-1. This resulted approximately 35% higher than those observed in the SBR, since the ultrafiltration membrane avoided the washout of dispersed and filamentous bacteria capable of storing PHA. Furthermore, while maximizing PHA productivity in conventional SBR systems led to process dysfunctions, in the SBMBR system it helped mitigate these issues by reducing membrane fouling behaviour. The results of this study supported the possibility to achieve combined recovery of reclaimed water and high-value added bioproducts using membrane technology, leading the way for agro-food industrial wastewater valorization in the frame of a circular economy model.

Keywords: Agro-food wastewater; Food to microorganism; Membrane bioreactor; Mixed microbial culture; Polyhydroxyalkanoate; Reclaimed water.

MeSH terms

Bacteria
Bioreactors / microbiology
Polyhydroxyalkanoates*
Sewage
Wastewater*

Substances

Wastewater
Polyhydroxyalkanoates
Sewage