Continuous lactate-driven dark fermentation of restaurant food waste: Process characterization and new insights on transient feast/famine perturbations

Lois Regueira-Marcos; Raúl Muñoz; Octavio García-Depraect

doi:10.1016/j.biortech.2023.129385

Continuous lactate-driven dark fermentation of restaurant food waste: Process characterization and new insights on transient feast/famine perturbations

Bioresour Technol. 2023 Oct:385:129385. doi: 10.1016/j.biortech.2023.129385. Epub 2023 Jun 25.

Authors

Lois Regueira-Marcos¹, Raúl Muñoz¹, Octavio García-Depraect²

Affiliations

¹ Institute of Sustainable Processes, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain.
² Institute of Sustainable Processes, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain. Electronic address: octavio.garcia@uva.es.

PMID: 37364653
DOI: 10.1016/j.biortech.2023.129385

Abstract

The effect of hydraulic retention time (HRT) on the continuous lactate-driven dark fermentation (LD-DF) of food waste (FW) was investigated. The robustness of the bioprocess against feast/famine perturbations was also explored. The stepwise HRT decrease from 24 to 16 and 12 h in a continuously stirred tank fermenter fed with simulated restaurant FW impacted on hydrogen production rate (HPR). The optimal HRT of 16 h supported a HPR of 4.2 L H₂/L-d. Feast/famine perturbations caused by 12-h feeding interruptions led to a remarkable peak in HPR up to 19.2 L H₂/L-d, albeit the process became stable at 4.3 L H₂/L-d following perturbation. The occurrence of LD-DF throughout the operation was endorsed by metabolites analysis. Particularly, hydrogen production correlated positively with lactate consumption and butyrate production. Overall, the FW LD-DF process was highly sensitive but resilient against transient feast/famine perturbations, supporting high-rate HPRs under optimal HRTs.

Keywords: Acidogenic fermentation; Biohydrogen; Hydraulic retention time; Organic waste; Process disturbances.

MeSH terms

Bioreactors
Fermentation
Food*
Hydrogen / metabolism
Refuse Disposal*
Restaurants

Substances

Hydrogen