title: Effects of operational parameters on dark fermentative hydrogen production from biodegradable complex waste biomass.
abstract: This work aimed to investigate the effect of the initial pH, combination of food to microorganism ratio (F/M) and initial pH, substrate pre-treatment and different inoculum sources on the dark fermentative biohydrogen (H2) yields. Three model complex waste biomasses (food waste, olive mill wastewater (OMWW) and rice straw) were used to assess the effect of the aforementioned parameters. The effect of the initial pH between 4.5 and 7.0 was investigated in batch tests carried out with food waste. The highest H2 yields were shown at initial pH 4.5 (60.6 ± 9.0 mL H2/g VS) and pH 5.0 (50.7 ± 0.8 mL H2/g VS). Furthermore, tests carried out with F/M ratios of 0.5, 1.0 and 1.5 at initial pH 5.0 and 6.5 revealed that a lower F/M ratio (0.5 and 1.0) favored the H2 production at an initial pH 5.0 compared to pH 6.5. Alkaline pre-treatment of raw rice straw using 4% and 8% NaOH at 55°C for 24h, increased the H2 yield by 26 and 57-fold, respectively. In the dark fermentation of OMWW, the H2 yield was doubled when heat-shock pre-treated activated sludge was used as inoculum in comparison to anaerobic sludge. Overall, this study shows that the application of different operating parameters to maximize the H2 yields strongly depends on the biodegradability of the substrate.
authors.affiliation: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Di Biasio 43, 03043 Cassino, FR, Italy; Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125 Naples, Italy. Electronic address: a.ghimire@unicas.it.
authors.forename: Anish
authors.initials: A
authors.lastname: Ghimire
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125 Naples, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Sposito
authors.affiliation: Department of Mathematics and Applications Renato Caccioppoli, University of Naples Federico II, via Cintia, Monte S. Angelo, I-80126 Naples, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Frunzo
authors.affiliation: INRA, UR0050 Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Trably
authors.affiliation: INRA, UR0050 Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Escudié
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125 Naples, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Pirozzi
authors.affiliation: UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands.
authors.forename: Piet N L
authors.initials: PN
authors.lastname: Lens
authors.affiliation: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Di Biasio 43, 03043 Cassino, FR, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Esposito
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D056804:Biofuels / Q000032:analysis*; D018533:Biomass; D019149:Bioreactors; D005285:Fermentation; D005502:Food; D005735:Garbage; D006859:Hydrogen / Q000032:analysis* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D062611:Solid Waste / Q000032:analysis*
chemical_list: D056804:Biofuels; D062611:Solid Waste; D006859:Hydrogen
keywords: Biofuels; Biohydrogen; Dark fermentation; Waste biomass; Waste valorization