scholarly journals Effect of pH on the Economic Potential of Dark Fermentation Products from Used Disposable Nappies and Expired Food Products

2021 ◽  
Vol 11 (9) ◽  
pp. 4099
Author(s):  
Dimitris Zagklis ◽  
Marina Papadionysiou ◽  
Konstantina Tsigkou ◽  
Panagiota Tsafrakidou ◽  
Constantina Zafiri ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Hydrogen Production ◽  
Volatile Fatty Acids ◽  
Food Products ◽  
Treatment Method ◽  
Dark Fermentation ◽  
Biodiesel Production ◽  
Economic Potential ◽  
Fermentation Products ◽  
Ph Values

Used disposable nappies constitute a waste stream that has no established treatment method. The purpose of this study was the assessment of the dark fermentation of used disposable nappies and expired food products under different pH values. The biodegradable part of the used disposable nappies was recovered and co-fermented with expired food products originating from supermarkets. The recoverable economic potential of the process was examined for different volatile fatty acids exploitation schemes and process pH values. The process pH strongly affected the products, with optimum hydrogen production at pH 6 (4.05 NLH2/Lreactor), while the amount of produced volatile fatty acids was maximized at pH 7 (13.44 g/L). Hydrogen production was observed at pH as low as pH 4.5 (2.66 NLH2/Lreactor). The recoverable economic potential was maximized at two different pH values, with the first being pH 4.5 with minimum NaOH addition requirements (181, 138, and 296 EUR/ton VS of substrate for valorization of volatile fatty acids through microbial fuel cell, biodiesel production, and anaerobic digestion, respectively) and the second being pH 6, where the hydrogen production was maximized with the simultaneous production of high amounts of volatile fatty acids (191, 142, and 339 EUR/ton VS of substrate respectively).

Sequential generation of hydrogen and lipids from starch by combination of dark fermentation and microalgal cultivation

RSC Advances ◽  
2015 ◽  
Vol 5 (94) ◽  
pp. 76779-76782 ◽  
Author(s):  
Hong-Yu Ren ◽  
Bing-Feng Liu ◽  
Fanying Kong ◽  
Lei Zhao ◽  
Nan-Qi Ren
Keyword(s):  
Fatty Acids ◽  
Hydrogen Production ◽  
Volatile Fatty Acids ◽  
Lipid Production ◽  
Dark Fermentation ◽  
Simultaneous Treatment ◽  
Microalgal Cultivation ◽  
Fermentative Hydrogen Production ◽  
Fermentative Hydrogen ◽  
Sequential Generation

Dark fermentative hydrogen production and microalgal lipid production was successfully combined to enhance the energy conversion from starch with simultaneous treatment of volatile fatty acids in the effluent.

scholarly journals Dark Fermentation of Sweet Sorghum Stalks, Cheese Whey and Cow Manure Mixture: Effect of pH, Pretreatment and Organic Load

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1017
Author(s):  
Margarita Andreas Dareioti ◽  
Aikaterini Ioannis Vavouraki ◽  
Konstantina Tsigkou ◽  
Constantina Zafiri ◽  
Michael Kornaros
Keyword(s):  
Fatty Acids ◽  
Hydrogen Production ◽  
Sweet Sorghum ◽  
Volatile Fatty Acids ◽  
Cheese Whey ◽  
Dark Fermentation ◽  
Organic Load ◽  
Anaerobic Sludge ◽  
Hydrogen Yield ◽  
Cow Manure

The aim of this study was to determine the optimal conditions for dark fermentation using agro-industrial liquid wastewaters mixed with sweet sorghum stalks (i.e., 55% sorghum, 40% cheese whey, and 5% liquid cow manure). Batch experiments were performed to investigate the effect of controlled pH (5.0, 5.5, 6.0, 6.5) on the production of bio-hydrogen and volatile fatty acids. According to the obtained results, the maximum hydrogen yield of 0.52 mol H2/mol eq. glucose was measured at pH 5.5 accompanied by the highest volatile fatty acids production, whereas similar hydrogen productivity was also observed at pH 6.0 and 6.5. The use of heat-treated anaerobic sludge as inoculum had a positive impact on bio-hydrogen production, exhibiting an increased yield of 1.09 mol H2/mol eq. glucose. On the other hand, the pretreated (ensiled) sorghum, instead of a fresh one, led to a lower hydrogen production, while the organic load decrease did not affect the process performance. In all experiments, the main fermentation end-products were volatile fatty acids (i.e., acetic, propionic, butyric), ethanol and lactic acid.

scholarly journals Zeolite addition to improve biohydrogen production from dark fermentation of C5/C6-sugars and Sargassum sp. biomass

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. M. Silva ◽  
A. A. Abreu ◽  
A. F. Salvador ◽  
M. M. Alves ◽  
I. C. Neves ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Anaerobic Bacteria ◽  
Dark Fermentation ◽  
Inorganic Materials ◽  
Biohydrogen Production ◽  
High Rate ◽  
Continuous Reactor ◽  
Organic Loading Rate ◽  
Fermentation Products ◽  
Zeolite Type

AbstractThermophilic biohydrogen production by dark fermentation from a mixture (1:1) of C5 (arabinose) and C6 (glucose) sugars, present in lignocellulosic hydrolysates, and from Sargassum sp. biomass, is studied in this work in batch assays and also in a continuous reactor experiment. Pursuing the interest of studying interactions between inorganic materials (adsorbents, conductive and others) and anaerobic bacteria, the biological processes were amended with variable amounts of a zeolite type-13X in the range of zeolite/inoculum (in VS) ratios (Z/I) of 0.065–0.26 g g−1. In the batch assays, the presence of the zeolite was beneficial to increase the hydrogen titer by 15–21% with C5 and C6-sugars as compared to the control, and an increase of 27% was observed in the batch fermentation of Sargassum sp. Hydrogen yields also increased by 10–26% with sugars in the presence of the zeolite. The rate of hydrogen production increased linearly with the Z/I ratios in the experiments with C5 and C6-sugars. In the batch assay with Sargassum sp., there was an optimum value of Z/I of 0.13 g g−1 where the H2 production rate observed was the highest, although all values were in a narrow range between 3.21 and 4.19 mmol L−1 day−1. The positive effect of the zeolite was also observed in a continuous high-rate reactor fed with C5 and C6-sugars. The increase of the organic loading rate (OLR) from 8.8 to 17.6 kg m−3 day−1 of COD led to lower hydrogen production rates but, upon zeolite addition (0.26 g g−1 VS inoculum), the hydrogen production increased significantly from 143 to 413 mL L−1 day−1. Interestingly, the presence of zeolite in the continuous operation had a remarkable impact in the microbial community and in the profile of fermentation products. The effect of zeolite could be related to several properties, including the porous structure and the associated surface area available for bacterial adhesion, potential release of trace elements, ion-exchanger capacity or ability to adsorb different compounds (i.e. protons). The observations opens novel perspectives and will stimulate further research not only in biohydrogen production, but broadly in the field of interactions between bacteria and inorganic materials.

Use of organic waste for biohydrogen production and volatile fatty acids via dark fermentation and further processing to methane

2019 ◽  
Vol 44 (44) ◽  
pp. 24110-24125 ◽  
Author(s):  
Tobias Weide ◽  
Elmar Brügging ◽  
Christof Wetter ◽  
Antonio Ierardi ◽  
Marc Wichern
Keyword(s):  
Fatty Acids ◽  
Organic Waste ◽  
Volatile Fatty Acids ◽  
Dark Fermentation ◽  
Biohydrogen Production

Fermentation of Chlorella sp. for anaerobic bio-hydrogen production: Influences of inoculum–substrate ratio, volatile fatty acids and NADH

2011 ◽  
Vol 102 (22) ◽  
pp. 10480-10485 ◽  
Author(s):  
Jingxian Sun ◽  
Xianzheng Yuan ◽  
Xiaoshuang Shi ◽  
Chunfeng Chu ◽  
Rongbo Guo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Hydrogen Production ◽  
Volatile Fatty Acids ◽  
Chlorella Sp ◽  
Substrate Ratio
Sign in / Sign up

Export Citation Format

Share Document