Degradation of volatile fatty acids in highly efficient anaerobic digestion

Wang, Qunhui; Kuninobu, Masaaki; Ogawa, Hiroaki; Kato, Yasuhiko

doi:10.1016/s0961-9534(99)00016-1

Cited by 267 publications

(140 citation statements)

References 18 publications

Supporting

Mentioning

113

Contrasting

Unclassified

Order By: Relevance

“…more n-butyric acid and n-valeric acid produced than their isomers (Fig 5.12 and 5.13). Similar results have been reported in previous batch assays carried out on similar substrates (Wilson et al, 2004, Russo et al, 2009). Wang et al (1999 indicate that the decomposition rates of VFAs (C 2 -C 6 ) with a straight chain (normal form) were greater than their respective branched isomers suggesting that foams and cardboard provide easily digestible intermediate VFAs for bacteria.…”

Section: Lca Of Light-weight Eco-compositessupporting

confidence: 91%

Life Cycle Assessment (LCA) of Light-Weight Eco-composites

Guo¹

2012

Springer Theses

View full text Add to dashboard Cite

LCA of Light-weight Eco-composites Statement of originality 2 Statement of originalityI hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person.Contributions made to the research of this thesis by others, with whom I have worked with are explicitly acknowledged. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others with data collection and modification of process-oriented model DNDC is acknowledged. Miao GuoSep 2010 LCA of Light-weight Eco-compositesAbstract 3 AbstractThe environmental profiles of novel wheat based foam materials were investigated in this thesis using Life Cycle Assessment (LCA) methods. The LCAs were developed using primary data collected from industrial sources combined with new laboratory experiments supplemented with secondary data from publicly available sources.Laboratory research was conducted to obtain important missing data on WBFs for the LCA modelling, including physico-chemical parameters, biodegradability and energy recovery under anaerobic digestion conditions.Contribution analysis suggested that the emissions evolved from the wheat agroecosystem and PVOH production, together with the energy and infrastructure involved in WBF production were the major contributors to the environmental burdens of the WBF life cycle in most impact categories. The atmospheric emissions resulting from WBF degradation at the end-of-life also emerged as another important contributor to environmental impact. Amongst the diverse ‗end-of-life' scenarios examined, AD and home composting were suggested to be the optimum choices for WBF waste treatment. This research discusses two N 2 O modelling approaches and presents a method to expand the system boundary by integrating the process-oriented model DNDC for field emissions into the LCA. Sensitivity analysis suggests that the environmental profiles of agricultural products are influenced substantially by the system boundary definition. LCA of Light-weight Eco-compositesAbstract 4 Furthermore, it suggests that the ‗general rule' in LCA practice by applying an empirical model or a default emission factor (EF) could deliver unreliable LCA findings.This study also evaluated the sensitivity of the LCA results to methodology and data variations and quantified the uncertainties in the LCA outcomes arising from uncertainty in the inventory and data variability. This has led to an increase in confidence in the LCA findings. At the same time it indicates the areas where improvements in data or methods are needed in order for robust conclusions to be drawn and unbiased information to be delivered e.g. the methodological rigidity of characterization models, the IPCC Tier 1 EF uncertainty range. LCA of Light-weight Eco-compositesAcknowledgements 5

show abstract

Section: Lca Of Light-weight Eco-compositessupporting

confidence: 91%

Life Cycle Assessment (LCA) of Light-Weight Eco-composites

Guo¹

2012

Springer Theses

View full text Add to dashboard Cite

show abstract

“…Se ha reportado que en dietas donde haya un sustrato que aporte buena energía durante las primeras 24 h de fermentación, generalmente se presenta un aumento en la proporción de AGV, el cual puede disminuir en posteriores horas, debido a que es posible que los microorganismos degraden los AGV para obtener energía (Wang et al, 1999). De manera general, en los resultados de este estudio, el porcentaje de AGV totales a las 24 h de incubación, aumentó con la adición de fuentes de ácidos grasos poliinsaturados (AGPI) (3% MS).…”

Section: Producción Total Y Proporción Molar De Agvunclassified

Efecto sobre la fermentación in vitro de mezclas de Tithonia diversifolia, Cenchrus clandestinum y grasas poliinsaturadas

Iglesias¹,

Ledesma²,

Arizala³

2017

Mesoam. Agron.

View full text Add to dashboard Cite

The aim of this study was evaluated by in vitro, the effect of mixing wild sunflower (Tithonia diversifolia), kikuyu (Cenchrus clandestinum) and concentrated feed, with the addition of polyunsaturated fatty acids (AGPI) on the production of methane (CH4 ml/g MSd), dry matter digestibility (%DIVMS) and production of volatile fatty acids (AGV). The research was conducted in NUTRILAB laboratory (Medellin, Colombia) in September 2015. Three combinations of AGPI rich lipid sources were used with a total maximum inclusion level corresponding to 3% of incubated dry matter. Combinations of lipid sources were: SAGPI1: 0.5% soya oil, 0.5% sish oil, 2% rich in omega 3 bypass fat. SAGPI2: 1% Soya oil, 0.5% fish oil, 1.5% bypass fat rich in omega 3. SAGPI3: 2.5% Soya oil, 0.5% fish oil. A source of bypass fat (GSP) was also used. The results were processed using pre-planned test comparisons through the PROC MIXED-SAS.The methane production in vitro decreased (p<0.05), while the dry matter digestibility increased (p<0.05) 24 and 48 hours after wild sunflower was include and / or AGPI or both into the mixtures. In the molar ratio of AGV (%), acetic acid showed an increased presence. The inclusion of forage like wild sunflower and sources of AGPI supplementation in cattle, could be a strategy to reduce methane emissions without causing a detriment to the ruminal fermentation.

show abstract

“…The fact that these VFAs were found in these proportions is probably due to the rate constants for their degradation. VFAs are degraded according to first order kinetics, as reported by Wang et al [24] after investigating AD of pretreated (ultrasonic disintegration, heating, and freezing) and untreated waste activated-sludge. They found that propionate is degraded more slowly than acetate (k HPro = 0.02878 h −1 and k HAc = 0.06119 h −1 , respectively respectively).…”

Section: Vfas Formationmentioning

confidence: 91%

Effect of Individual Components of Lignocellulosic Biomass on Methane Production and Methanogen Community Structure

Pokój

Klimiuk

Bułkowska

et al. 2018

Waste Biomass Valor

View full text Add to dashboard Cite

One of the major factors that influences the economic feasibility of biogas production is the availability of digestible feedstocks. There is little research on the influence of the chemical composition of biomass on biogas synthesis, especially with regard to the content of lignocellulosic materials. Therefore, the aim of this study was to estimate how differences in the content of cellulose and lignin in lignocellulosic biomass influence the concentrations of individual volatile fatty acids (VFAs) and biogas production. Additionally, the structure of the methanogenic community was examined. The removal of fibrous and non-fibrous materials, the concentrations of individual VFAs, methane production and methanogen community structure were examined during digestion of Zea mays L. and Miscanthus sacchariflorus silages. Organics were removed with higher efficiency during the digestion of Z. mays silage than during digestion of M. sacchariflorus. This was due to the higher non-fibrous carbohydrates content in Z. mays than in M. sacchariflorus. In both digesters, propionate predominated throughout experiment. The methanogenic community in the digester fed with Z. mays was more diverse than that in the digester with M. sacchariflorus. Analysis of 16S rRNA sequences showed that six acetoclastic and four hydrogenotrophic methanogens were present in the digester fed with Z. mays L., while five acetoclastic and three hydrogenotrophic methanogens were in the digester fed with M. sacchariflorus. The abundance of Methanosarcina correlated significantly with the concentration of all analyzed VFAs.Keywords Crop silage · Anaerobic digestion · Syntrophic volatile fatty acids oxidation · Archaeal community structure · Methane yield Statement of NoveltyTo introduce novel biomass types for biogas production, an integrated evaluation approach has to be applied. The present study delivers a combination of technological and microbial data about the process of anaerobic digestion of the commonly used substrates Zea mays L. silage and Miscanthus sacchariflorus silage, the latter of which has a high content of lignin and cellulose. The correlations between the abundance of methanogenic microorganisms and the concentrations of individual VFAs produced during digestion of these substrates were estimated. The results reveal novel associations between the type of substrate used, the rate of methane production and the structure of the methanogenic community. The use of materials with a high lignin content limits biodiversity in the anaerobic digesters, which can result in decreases in anaerobic digestion performance and biogas production.

show abstract

Degradation of volatile fatty acids in highly efficient anaerobic digestion

Cited by 267 publications

References 18 publications

Life Cycle Assessment (LCA) of Light-Weight Eco-composites

Life Cycle Assessment (LCA) of Light-Weight Eco-composites

Efecto sobre la fermentación in vitro de mezclas de Tithonia diversifolia, Cenchrus clandestinum y grasas poliinsaturadas

Effect of Individual Components of Lignocellulosic Biomass on Methane Production and Methanogen Community Structure

Contact Info

Product

Resources

About