Deconstructing the Livestock Manure Digester and Biogas Controversy.

Analysis for microbial denitrification and antibiotic resistance during anaerobic digestion of cattle manure containing antibiotic

Responses of bacterial and archaeal communities to the addition of straw during anaerobic digestion of manure at different temperatures (37°C, 44°C and 52°C) were investigated using five laboratory-scale semi-continuous stirred tank reactors. The results revealed that including straw as co-substrate decreased the species richness for bacteria, whereas increasing the operating temperature decreased the species richness for both archaea and bacteria, and also the evenness of the bacteria. Taxonomic classifications of the archaeal community showed that Methanobrevibacter dominated in the manure samples, while Methanosarcina dominated in all digesters regardless of substrate. Increase of the operating temperature to 52°C led to increased relative abundance of Methanoculleus and Methanobacterium. Among the bacteria, the phyla Firmicutes and Bacteroidetes dominated within all samples. Compared with manure itself, digestion of manure resulted in a higher abundance of an uncultured class WWE1 and lower abundance of Bacilli. Adding straw to the digesters increased the level of Bacteroidia, while increasing the operating temperature decreased the level of this class and instead increased the relative abundance of an uncultured genus affiliated to order MBA08 (Clostridia). A considerable fraction of bacterial sequences could not be allocated to genus level, indicating that novel phylotypes are resident in these communities.

Life cycle environmental impacts of compressed biogas production through anaerobic digestion of manure and municipal organic waste

Abstract. Ammonia emission from manure following land application reduces fertilizer value of the manure and could have adverse impacts on the environment. Manure pretreatments and methods of manure application, however, may impact ammonia volatilization. Field- and lab-scale experiments were conducted to study the effects of anaerobic digestion (AD) and manure application methods (surface application and manure injection) on ammonia emission. In general, most of the ammonia emissions occurred within 5 d after manure application. Soils receiving undigested manure (UM) emitted more ammonia than soils receiving digested manure (DM) irrespective of manure application method. Surface-applied DM resulted in 56% less ammonia emission than surface-applied UM, while injected DM emitted 27% less than injected UM. Although injected DM did not significantly affect ammonia emission for both application methods, injected UM resulted in 42% less ammonia emission than surface applied UM. Surface application of UM exhibited the highest ammonia emission flux (0.78 g m -2 d -1 ) immediately after application but the flux dropped to zero within 3 d. The lowest initial ammonia flux of 0.17 g m -2 d -1 , which gradually approached zero within 5 d, was observed from injected DM. Similar results were obtained from field studies as follows. Surface applied DM resulted in 49% less ammonia emission than surface applied UM. Surface application resulted in 63% and 25% more ammonia loss than manure injection for UM and DM, respectively. Manure injection was thus a more effective method for mitigation of ammonia emission than surface application. Together, these studies indicate that land application of DM is both economically (retention of manure fertilizer-value) and environmentally friendlier (reduced ammonia emissions) than application of raw manure or UM.

Improving the biogas yield of manure: Effect of pretreatment on anaerobic digestion of the recalcitrant fraction of manure

Chapter 16 - Progress in Anaerobic Digestion of Manures

Engineering in Life SciencesVolume 11, Issue 5 p. 455-455 In this issueFree Access In this issue First published: 14 October 2011 https://doi.org/10.1002/elsc.201190033AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Dairy manure mixing for biogas production Rico et al., Eng. Life Sci. 2011, 11, 476–481. Dairy manure can either be disposed or turned into valuable products by anaerobic digestion: (i) biogas, which can be used as a source for green electricity, heat or fuel; (ii) digested substrate, also called digestate, a fertilizer in agriculture. While many studies have investigated mixing strategies in anaerobic digesters, there is only limited information for mixing in anaerobic digestion of manure. In this issue, researchers from the University of Cantabria, Santander, Spain, evaluate the influence of reactor content recirculation rate on biogas production during mesophilic anaerobic digestion of airy manure in a 1.5 m3 pilot digester. The key determinants of biogas production are the hydraulic retention time (HRT) of the substrate and the degree of contact between the incoming substrate and the viable bacterial population. The authors conclude that for long HRTs the degree of mixing has only a minimal effect on biogas production……………476. http://dx.doi.org/10.1002/elsc.201100010 Honey mushroom culture: Aeration rate and antioxidant property Lung and Hsieh, Eng. Life Sci. 2011, 11, 482–490. Armillaria mellea, also called honey mushroom, is an edible mushroom used in traditional Asian medicine. Bioreactive compounds derived from mushrooms, including polysaccharides, display a variety of immunomodulating, antitumor and antioxidant activity. Submerged cultures are efficiently used for polysaccharide production from these mushrooms. Although several studies have focused on optimization of submerged culture conditions, the effects of the aeration rate have not been studied in detail. In this issue, optimized production of biomass and exopolysaccharide (EPS) is studied by authors from Taiwan. They evaluate changes of the aeration rate of an A. mellea culture performed in a 5L-stirred-tank bioreactor. EPS produced in the proposed optimal two-stage aeration rate culture is not only produced at a high yield, but also displays a high molecular weight with effective antioxidant properties.……………482 http://dx.doi.org/10.1002/elsc.2011000003 Plant cell culture system for gymnemic acid production Nagella et al., Eng. Life Sci. 2011, 11, 537–540. Traditional medicine uses plant extracts or infusions from wild or cultivated plants. For efficient use as pharmaceuticals large-scale septic and controllable production processes are needed. Gymnema sylvestre, an important medicinal plant, contains the bioactive gymnemic acids, which have anti-diabetic properties and may also be used to treat obesity. Preliminary reports have already described callus and cell suspension cultures of G. sylvestre. In this issue, authors from Seoul, South Korea, and Dharwad, India, present the first systematic approach to establish a suspension culture system for the production of gymnemic acid. Inoculum density, medium components, the carbon source, as well as the concentration of sucrose in the medium were optimized for efficient productivity of gymnemic acid. The results of the current study are the first step for large-scale production of gymnemic acid in cell culture.……………537 http://dx.doi.org/10.1002/elsc.2010000167 Volume11, Issue5October 2011Pages 455-455 RelatedInformation

Model-based analysis of greenhouse gas emission reduction potential through farm-scale digestion

Life cycle assessment of the use of laser radiation in biogas production from anaerobic digestion of manure

Greenhouse gas emissions and biogas potential from livestock in Ecuador

Microbial analysis of anaerobic digester reveals prevalence of manure microbiota

Ammonia emissions from the field application of liquid dairy manure after anaerobic digestion or mechanical separation in Ontario, Canada

The use of off-farm materials as amendments in anaerobic digestion of manure is an option that is being explored more extensively due to the benefits of boosting methane production and making the process more economical for the farmer. The addition of varying amounts of glycerol, which is a by-product in the biodiesel industry, was used as an amendment to anaerobic digestion of hog manure in bench-scale tests. The use of 2% glycerol produced the greatest amount of methane and biogas, while the addition of 4% glycerol resulted in an overloading of chemical oxygen demand (COD) and digester failure. The addition of 1% glycerol doubled the methane and biogas production, and there appeared to be no detrimental effects of using crude, industrial-based glycerol compared to pure, chemical-grade glycerol.

Anaerobic digestion of manure and mixture of manure with lipids: biogas reactor performance and microbial community analysis

The effect of anaerobic digestion (AD), coarse solids removal, and a manure additive More Than ManureTM (MTMTM) on ammonia (NH3) emission from raw (Non AD) dairy manure and AD manure was studied during 110 days of storage. The study consisted of eight treatments in duplicate: AD manure and non AD manure, with and without coarse solids, and with and without MTMTM additive. These studies were conducted in a naturally ventilated barn. The nitrogen content of manure, especially the ammoniacal nitrogen, played an important role in NH3 emission. During the first 11 weeks of the storage, AD manure had significantly greater peak (33 to 38 ppm) concentrations of NH3, and NH3 fluxes (94 to 130 μg min−1 m−2) compared to raw manure (14 to 25 ppm and 55 to 81 μg min−1 m−2, respectively). From the 11th week until the end of storage, there was no significant difference in NH3 emissions across the manure treatments. The presence of course solids resulted in significanlty less peak NH3 for non AD manure when data were evaluated for the whole storage period. The manure additive MTMTM did not have a significant effect on NH3 emissions during storage, however, temperature was positively related to NH3 emissions. Total ammoniacal nitrogen and solids concentration in manure was the most important factors affecting NH3 emissions during storage.