A novel method for increasing biohydrogen production from food waste using electrodialysis

Abstract

The impact of continuous removal of volatile fatty acids on fermentative hydrogen production from food waste (FW) in a Continuously Stirred Tank Reactor (CSTR) was evaluated. Two experimental phases were conducted, a control phase and one in which volatile fatty acids were removed continuously from the reactor for the first time by electrodialysis (ED). Hydrogen yields were 64.7 cm 3 H 2 /g VS and 227.3 cm 3 H 2 /g VS for control phase, and ED phase respectively. Continuous removal of volatile fatty acids during fermentation not only increased H 2 yields but increased the production of volatile fatty acids (a valuable chemical feedstock) from 0.14 g/g VS to 0.34 g/g VS .

Volatile Fatty Acid Production from Organic Waste with the Emphasis on Membrane-Based Recovery

“…The removal of VFAs increased the biohydrogen production yield by 3.75-fold and increased the carbohydrate utilization rate from 12% to 15%. This is consistent with the findings of Hassan et al (2017) [21], who have combined the production of dark hydrogen with electrodialysis. Tao et al (2016) [113] used a microfiltration system combined with electrodialysis to recover VFAs from a VFA production bioreactor.…”

“…Recovery of VFAs prevents the inhibition of microbes, leading to the stability and high production of VFAs by continuously removing VFAs from the reactor [14,19,21]. However, VFA recovery from fermented effluent is a challenging process because of the low concentration of VFAs, the complexity of the mixture, the physicochemical nature of the fermented effluent, and processing cost, which accounts for approximately about 30-40% of the total cost, all of which contribute to the VFA recovery processes [13].…”

“…Therefore, these fermented streams require a solid removal step to improve the efficiency of the recovery process [14]. Various techniques have been applied for VFA recovery, including liquid-liquid extraction [15], adsorption [16,17], membrane contactors [18], membrane reactors [19,20], electrodialysis [21,22] and membrane pervaporation [13]. Among them, membrane-based recovery appears to be a more promising technology than other techniques because of its economic and environmental potential [5,7,14].…”

Prolonged culture in aerobic environments alters Escherichia coli H2 production capacity

“…Multiple growth strategies for anaerobic respiration have been established for E coli . Modulating the carbon source, and the removal of metabolic intermediates prove effective methods for optimizing the yield of desired byproducts. Even doping with oxygen, usually a “poison” for dark fermentation, has been shown capable of improving H 2 yield showcasing the multiple roles every chemical actor may play in the regulation of anaerobic metabolism.…”

Bioenergy from biofuel residues and waste

“…The study strongly supports using MFC technology as pretreatment of solid substrates to improve biohydrogen yield from anaerobic digestion processes. Hassan et al (2019) evaluate the result of continuous elimination of fatty acids on fermentative biohydrogen production from food waste. The authors show for the first time that using electrodialysis with a continuously fed biohydrogen reactor running on food waste yielded significant increases in biohydrogen.…”