Effects of carbohydrate, protein and lipid content of organic waste on hydrogen production and fermentation products

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.

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Hydrogen production from organic waste

International Journal of Hydrogen Energy ◽

10.1016/s0360-3199(00)00125-7 ◽

2001 ◽

Vol 26 (6) ◽

pp. 547-550 ◽

Cited By ~ 46

Author(s):

Annika T Nielsen ◽

Helena Amandusson ◽

Robert Bjorklund ◽

Helen Dannetun ◽

Jörgen Ejlertsson ◽

...

Keyword(s):

Hydrogen Production ◽

Organic Waste

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Kinetics of Anaerobic Digestion of Dairy Fat Waste with Saponification Pre-Treatment

Jurnal Rekayasa Proses ◽

10.22146/jrekpros.48959 ◽

2019 ◽

Vol 13 (2) ◽

pp. 112 ◽

Cited By ~ 1

Author(s):

Rifki Wahyu Kurnianto ◽

Wiratni Budhijanto ◽

Rochim Bakti Cahyono

Keyword(s):

Anaerobic Digestion ◽

Lipid Content ◽

Alternative Energy ◽

Organic Waste ◽

High Lipid Content ◽

Dairy Fat ◽

High Lipid ◽

Pre Treatment ◽

Kinetics Of ◽

Floating Layer

Anaerobic digestion has been an attractive field of research in the era of energy crisis. Biogas, which is the product of anaerobic digestion, provides alternative energy, while at the same time it also prevents pollution due to organic waste accumulation. Among various organic wastes, dairy fat waste is a potential substrate for anaerobic digestion. Fat waste has high theoretical biogas potential because of its high lipid content. However, anaerobic digestion of organic waste with high lipid content is quite challenging. The main obstacle in anaerobic digestion of fat waste is its tendency to form insoluble floating layer on top of the liquid phase. This phenomenon hinders the access of hydrolytic bacteria to the substrate. Saponification is one of the methods to increase the solubility of the floating layer and hence to improve the availability of substrate for the bacteria. Saponification changes the lipid content into soap which has both polar and non-polar functional groups and the polar side will increase the solubility of the substrate in water. This study evaluated the effect of different dosage of base added as the reactant during saponification pre-treatment on the productivity of anaerobic digestion of dairy fat waste. The kinetics of the anaerobic digestion process was analyzed by mean of mathematical model. The variations of the alkaline dosages studied for saponification pre-treatment were 0.04 mol base/g sCOD; 0.02 mol base/g sCOD; and no pre-treatment for control reactor. This study proved that saponification increased the solubility of dairy fat waste. This result was confirmed by the hydrolysis constant value (kH) of 0.00782/day for reactor with saponification, which was twenty times of magnitude higher than the kH value of 0.00032/day in the reactor without saponification. However, the exposure to high pH during the saponification pre-treatment might somewhat inhibit indigenous acidogenic bacteria in the waste which results in lower methane yield in the reactors with saponification to be compared to the control reactor. A B S T R A KPeruraian anaerobik merupakan salah satu bidang riset yang sangat menarik perhatian dalam era krisis energi. Biogas tidak hanya menyediakan energi alternatif, tetapi juga dapat mencegah pencemaran akibat limbah organik. Limbah lemak susu adalah substrat yang potensial untuk proses peruraian anaerobik karena memiliki potensi biogas teoritis yang tinggi akibat kandungan lemaknya yang tinggi. Namun, peruraian anaerobik dari limbah organik dengan kandungan lemak yang tinggi memiliki tantangan tersendiri. Hambatan utama dalam peruraian anaerobik dari limbah lemak susu adalah kecenderungan untuk membentuk lapisan padatan yang tidak larut dan mengapung di bagian atas fase cair. Fenomena ini menghambat akses bakteri hidrolisis terhadap substrat. Saponifikasi adalah salah satu cara untuk meningkatkan kelarutan lapisan padatan tersebut, sehingga meningkatkan ketersediaan substrat untuk bakteri. Saponifikasi akan mengubah kandungan lemak menjadi sabun yang memiliki gugus fungsi polar maupun non-polar. Gugus fungsi yang bersifat polar akan meningkatkan kelarutan substrat dalam air. Studi ini mengevaluasi pengaruh dari berbagai dosis larutan basa yang ditambahkan sebagai reaktan selama perlakuan awal saponifikasi terhadap peruraian anaerobik limbah lemak susu. Kinetika proses peruraian anaerobik dianalisis dengan menggunakan model matematika. Variasi dosis yang diamati pengaruhnya untuk perlakuan awal saponifikasi adalah 0,04 mol basa/g sCOD; 0,02 mol basa/g sCOD; dan nol (tanpa perlakuan awal saponifikasi). Dari penelitian ini, terbukti bahwa saponifikasi berhasil meningkatkan kelarutan limbah lemak susu dan juga ditunjukkan oleh nilai konstanta hidrolisis (kH) 0,00782/hari lebih tinggi dua puluh kali lipat dibandingkan dengan nilai kH 0,00032/hari pada reaktor tanpa saponifikasi. Akan tetapi, penelitian ini juga mengindikasikan bahwa bakteri asidogenik bawaan substrat terhambat kinerjanya oleh paparan pH yang tinggi selama perlakuan awal saponifikasi berlangsung sehingga hasil gas metan yang diperoleh lebih rendah daripada reaktor kontrol.

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Photocatalytic and photoelectrochemical hydrogen production by photodegradation of organic substances

Pure and Applied Chemistry ◽

10.1351/pac-con-08-07-07 ◽

2009 ◽

Vol 81 (8) ◽

pp. 1441-1448 ◽

Cited By ~ 6

Author(s):

Panagiotis Lianos ◽

Nikoleta Strataki ◽

Maria Antoniadou

Keyword(s):

Titanium Dioxide ◽

Hydrogen Production ◽

Organic Waste ◽

Current Trend ◽

Waste Materials ◽

Organic Substances ◽

Nanocrystalline Titania ◽

Photoelectrochemical Hydrogen Production

Commercial nanocrystalline titania (titanium dioxide, TiO2) has been used to make TiO2 films, which were employed to photodegrade several organic substances under photocatalytic (PC) or photoelectrochemical (PEC) operation. Hydrogen was produced during both operations while electricity was additionally produced during the PEC operation. Both processes were studied as typical examples of the current trend in the effort to produce useful forms of energy by photodegradation of organic waste materials.

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Application of modified ADM1 to long-term experiments for methane/hydrogen production from model organic waste

Water Practice & Technology ◽

10.2166/wpt.2011.009 ◽

2011 ◽

Vol 6 (1) ◽

Cited By ~ 5

Author(s):

S. Soda ◽

K. Wada ◽

M. Okuda ◽

M. Ike

Keyword(s):

Hydrogen Production ◽

Methane Production ◽

Organic Waste ◽

Degradation Pathways ◽

Bacterial Populations ◽

Degrading Bacteria ◽

Production Experiment ◽

Methane Production Rate ◽

Simulation Results

The modified ADM1 including lactate and ethanol was verified using experimental data for methane/hydrogen production processes from model organic waste. Monosaccharides were presumably degraded into acetate, lactate, butyrate, and ethanol; lactate is further degraded into propionate and acetate; ethanol is degraded into acetate. The methane production experiment was carried out using an 8-L reactor operated at 55°C, pH 6.8, and sludge retention time (SRT) of 7–20 days for 370 days. Concentrations of carbohydrates, monosaccharides, butyrate, propionate, valerate, acetate, and the methane production rate were simulated well by the modified ADM1. The ratio of degradation pathways from monosaccharides to acetate, lactate, butyrate, and ethanol were inferred, respectively, to be 0.4, 0.6, 0.0, and 0.0. The hydrogen production experiment was carried out using a 2-L (1.5L) reactor operated at 35°C, pH 6.0-6.5, and SRT of 0.5–2.0 days for 370 days. The simulation results suggested that all bacterial populations except the sugar-degrading bacteria were washed out from the reactor because of the short SRT. The respective ratios of degradation pathways from monosaccharides to acetate, lactate, propionate, and ethanol were inferred to be 0.55, 0.0, 0.4, and 0.05 at pH 6.5 and 0.7, 0.2, 0.05 and 0.05 at pH 6.0.

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Kinetics of Biohydrogen Production from Ozonated Palm Oil Mill Effluent Using C. butyricum and C. acetobutylicum Co-Culture

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.1515 ◽

2012 ◽

Vol 512-515 ◽

pp. 1515-1519 ◽

Cited By ~ 7

Author(s):

Nipon Pisutpaisal ◽

Saowaluck Hoasagul

Keyword(s):

Hydrogen Production ◽

Palm Oil ◽

Biohydrogen Production ◽

Palm Oil Mill Effluent ◽

Batch Reactors ◽

Fermentation Products ◽

Ozone Pretreatment ◽

Palm Oil Mill ◽

Kinetics Of ◽

Mesophilic Condition

Kinetics of mesophilic biohydrogen production from ozone-pretreated palm oil mill effluent (POME) using C. butyricum and C. acetobutylicum co-culture was investigated. All experiments were setup in 0.5-L batch reactors under mesophilic condition (37°C), pH 6, and POME concentration of 5,000-30,000 mg COD L-1. At the concentration of 15,000 mg COD L-1, maximum hydrogen production yield for non-ozone pretreated POME and ozone pretreated POME were 318 and 122 mL g-1 CODremoved, respectively. Acetic and butyric acids were dominant fermentation products in liquid phase. Ozone-pretreatment of POME showed no significant improvement on the hydrogen production by the co-culture.

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Determination of the lipid content of organic waste using time-domain nuclear magnetic resonance

Waste Management ◽

10.1016/j.wasman.2021.11.013 ◽

2022 ◽

Vol 138 ◽

pp. 41-48

Author(s):

S. Picard ◽

M. Cambert ◽

J.-M. Roger ◽

A. Davenel ◽

R. Girault ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Lipid Content ◽

Time Domain ◽

Organic Waste ◽

Nuclear Magnetic

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Effects of fish oil on growth kinetics and lipid accumulation in black soldier fly larvae

Journal of Insects as Food and Feed ◽

10.3920/jiff2021.0083 ◽

2021 ◽

pp. 1-8

Author(s):

A.K.S. Knudsen ◽

E.E. Jespersen ◽

M.J. Markwardt ◽

A. Johansen ◽

A.P. Ortind ◽

...

Keyword(s):

Fatty Acids ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Fish Oil ◽

Acid Composition ◽

Growth Kinetics ◽

Lipid Content ◽

Oil Content ◽

Black Soldier Fly ◽

Fermentation Products

The main purpose of this study is to characterise how substrate lipid content affects growth kinetics of black soldier fly (BSF) larvae. Growth curves of larvae were characterised in substrates composed of chicken feed supplemented by 0-30% fish oil, and lipid content and fatty acid composition of the prepupae were quantified to examine up-take and assimilation of fish oil by the larvae. Increasing contents of fish oil resulted in reduced specific growth rates, reduced weight of the prepupae, and increased mortality. The prepupae had similar lipid contents at 0-20% fish oil, while 30% fish oil increased the lipid content of prepupae. In contrast, the fatty acid composition of the prepupae showed a strong dependency on substrate fish oil content, indicating that the larvae increased their uptake of fish oil with increasing fish oil content. C16-C22 fatty acids were bioaccumulated from the fish oil, but particularly C20 and C22 fatty acids were apparently also shortened or further metabolised. Microbial fermentation products rapidly accumulated in the substrates, and substrate lipids and carbohydrates were preserved and remained available for the larvae throughout their growth period. These results point out that although BSF larvae can utilise high contents of substrate lipids, it may be at the expense of reduced growth performance, and with limited effects on the composition of their biomass.

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