Search results for "ethane"
showing 10 items of 2342 documents
Towards food, feed and energy crops mitigating climate change
2011
Agriculture is an important source of anthropogenic emissions of the greenhouse gases (GHG), methane (CH 4 ) and nitrous oxide (N 2 O), and crops can affect the microbial processes controlling these emissions in many ways. Here, we summarize the current knowledge of plant–microbe interactions in relation to the CH 4 and N 2 O budgets and show how this is promoting new generations of crop cultivars that have the potential to mitigate GHG emissions for future agricultural use. The possibility of breeding low GHG-emitting cultivars is a paradigm shift towards sustainable agriculture that balances climate change and food and bioenergy security.
Anaerobic membrane bioreactor (AnMBR) scale-up from laboratory to pilot-scale for microalgae and primary sludge co-digestion: Biological and filtrati…
2020
This research work proposes the scale-up evaluation in terms of biological and filtration performance from laboratory to pilot-scale of an anaerobic membrane bioreactor (AnMBR) co-digesting raw microalgae and primary sludge. Best operating conditions for this scale-up were energetically and economically assessed based on laboratory results. Economic balance showed 3% higher annual costs when operating a reactor at 100 d solids retention time (SRT) compared to 70 d SRT. Energetic balance showed a 5.5-fold increase in heat demand working at thermophilic temperature comparing to mesophilic. The AnMBR operating conditions were set at 70 d SRT and 35 °C. The pilot-scale and lab-scale co-digester…
Enhanced high-quality biomethane production from anaerobic digestion of primary sludge by corn stover biochar
2020
Abstract This study conducted batch and continuous tests to reveal the feasibility of corn stover biochar on improving anaerobic digestion of primary sludge (PS). Dosing biochar (1.82, 2.55 and 3.06 g/g Total Solids (TS)) in digester improved methane content increasing from 67.5% to 81.3–87.3% and enhanced methane production by 8.6–17.8%. Model analysis indicated that biochar accelerated PS hydrolysis and enhanced methane potential of PS. The mechanistic studies showed that biochar enhanced process stability provided by strong buffering capacity and alleviated NH3 inhibition. In continuous test over 116 days, the volatile solids (VS) destruction in the biochar-dosed digester increased by 14…
Co-digestion of harvested microalgae and primary sludge in a mesophilic anaerobic membrane bioreactor (AnMBR): Methane potential and microbial divers…
2020
Abstract Anaerobic co-digestion of primary sludge and raw microalgae (Scenedesmus and Chlorella) was performed in a lab-scale semi-continuous anaerobic membrane bioreactor to assess the biological performance and identify the microbial community involved in the co-digestion process. The reactor was operated at 35 °C for 440 days, working at a solids retention time of 100 days. The system achieved 73% biodegradability and showed high stability in terms of pH and volatile fatty acids. An enriched microbial community was observed. Of the several phyla, Chloroflexi and Proteobacteria were the most abundant. Cellulose-degraders phyla (Bacteroidetes, Chloroflexi and Thermotogae) were detected. Sy…
Anaerobic membrane bioreactors (AnMBR) treating urban wastewater in mild climates
2020
[EN] Feasibility of an AnMBR demonstration plant treating urban wastewater (UWW) at temperatures around 25-30 degrees C was assessed during a 350-day experimental period. The plant was fed with the effluent from the pretreatment of a full-scale municipal WWTP, characterized by high COD and sulfate concentrations. Biodegradability of the UWW reached values up to 87%, although a portion of the biodegradable COD was consumed by sulfate reducing organisms. Effluent COD remained below effluent discharge limits, achieving COD removals above 90%. System operation resulted in a reduction of sludge production of 36-58% compared to theoretical aerobic sludge productions. The membranes were operated a…
Species disparity response to mutagenesis of marine yeasts for the potential production of biodiesel.
2019
Abstract Background Among the third-generation biodiesel feed stock, oleaginous marine yeasts are the least studied microorganisms for such purpose. Results Wild strains yeasts were isolated from various Tunisian marine sources including fish waste (Candida tenuis CtTun15, Debaryomyces hansenii DhTun2015, Trichosporon asahii TaTun15 and Yarrowia lipolytica YlTun15) and seawater (Rhodotorula mucilaginosa RmTun15). Following incubation with ethyl methanesulfonate (EMS: 75 mM) for various periods of time (T15, T30, T45, T60 min), the cell viability of these strains responded differentially according to yeast species. For instance, mutated CtTun15 did not survive after 30 min of EMS treatment; …
Spatiotemporal patterns in methane flux and gas transfer velocity at low wind speeds: Implications for upscaling studies on small lakes
2016
Lakes contribute significantly to the global natural emissions of methane (CH4) and carbon dioxide. However, to accurately incorporate them into the continental carbon balance more detailed surveys of lacustrine greenhouse gas emissions are needed, especially in respect to spatiotemporal variability and to how this affects the upscaling of results. We investigated CH4 flux from a small, wind-shielded lake during 10 field trips over a 14 month period. We show that floating chambers may be used to calibrate the relationship between gas transfer velocity (k) and wind speed at 10 m height (U10) to the local system, in order to obtain more accurate estimates of diffusive CH4 flux than by applyin…
Assessing Methane Emission and Economic Viability of Energy Exploitation in a Typical Sicilian Municipal Solid Waste Landfill
2018
Sanitary landfills for municipal solid waste (MSW) represent one of the major anthropogenic source of GHGs emissions and are directly responsible of the climate changes we are facing nowadays. Indeed, the biodegradable organic matter of MSW undergoes anaerobic digestion producing the landfill gas (LFG), whose main components are CH4 and CO2. Therefore, biomethane energy exploitation in MSW landfills will reduce GHGs emission positively affecting the global warming. The aim of the present study was to assess the methane production in a Sicilian landfill by comparing the results from field measurements of methane emission and the estimates achieved by applying different mathematical models. A…
Removal of 2-butoxyethanol gaseous emissions by biotrickling filtration packed with polyurethane foam
2016
The removal of 2-butoxyethanol from gaseous emissions was studied using two biotrickling filters (BTF1 and BTF2) packed with polyurethane foam. Two different inoculum sources were used: a pure culture of Pseudomonas sp. BOE200 (BTF1) and activated sludge from a municipal wastewater treatment plant (BTF2). The bioreactors were operated at inlet loads (ILs) of 130 and 195 g m(-3) hour(-1) and at an empty bed residence time (EBRT) of 12.5s. Under an IL of ∼130 g m(-3) hour(-1), BTF1 presented higher elimination capacities (ECs) than BTF2, with average values of 106±7 and 68±8 g m(-3) hour(-1), respectively. However, differences in ECs between BTFs were decreased by reducing the irrigation inte…
Acclimatised rumen culture for raw microalgae conversion into biogas: Linking microbial community structure and operational parameters in anaerobic m…
2019
[EN] Ruminal fluid was inoculated in an Anaerobic Membrane Reactor (AnMBR) to produce biogas from raw Scenedesmus. This work explores the microbial ecology of the system during stable operation at different solids retention times (SRT). The 16S rRNA amplicon analysis revealed that the acclimatised community was mainly composed of Anaerolineaceae, Spirochaetaceae, Lentimicrobiaceae and Cloacimonetes fermentative and hydrolytic members. During the highest biodegradability achieved in the AnMBR (62%) the dominant microorganisms were Fervidobacterium and Methanosaeta. Different microbial community clusters were observed at different SRT conditions. Interestingly, syntrophic bacteria Gelria and …