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Journal of Environmental Management Jun 2024This works proposes a dynamic thermoeconomic analysis of a liquefied biomethane production plant to meet the fuel demand of a fleet of heavy duty trucks in the south of...
This works proposes a dynamic thermoeconomic analysis of a liquefied biomethane production plant to meet the fuel demand of a fleet of heavy duty trucks in the south of Italy. The biomethane is obtained from the upgrading of the biogas produced by means of anaerobic digestion through a plug flow reactor fed by organic fraction of municipal solid waste. The upgrading of the biogas is realized using a three-stage membrane compression process, producing a 96 % pure biomethane. The biomethane liquefaction is realized using a single-mixed refrigerant process and compared to a Linde cycle process. The whole system is assisted by solar energy to reduce the fossil energy consumption of the process and feed-in tariffs are considered as funding policy. The models for the anaerobic digestion, the biogas upgrading, and the biomethane liquefaction are in detail developed in MatLab. The anaerobic digestion model is based on the ADM1 biological model, integrated with a suitable heat transfer model. The biogas upgrading model is based on a simplified Fick model. The liquefaction model is based on an equivalent two heat-exchangers model, taking into account the transient heat transfer. All the components are then integrated in TRNSYS to perform the dynamic simulation for one operating year of the whole system. Results from the thermoeconomic analysis are outstanding in terms of profitability, showing a payback period of less than 2 years and a Net Present Value of the system of 402 M€. The great environmental impact is also confirmed by a Primary Energy Saving of 91 % and a dramatic reduction of 86 % of the CO equivalent emissions.
Topics: Biofuels; Solar Energy; Methane; Anaerobiosis; Italy; Models, Theoretical
PubMed: 38820789
DOI: 10.1016/j.jenvman.2024.121261 -
The ISME Journal Jan 2024Isolate studies have been a cornerstone for unraveling metabolic pathways and phenotypical (functional) features. Biogeochemical processes in natural and engineered...
Isolate studies have been a cornerstone for unraveling metabolic pathways and phenotypical (functional) features. Biogeochemical processes in natural and engineered ecosystems are generally performed by more than a single microbe and often rely on mutualistic interactions. We demonstrate the rational bottom-up design of synthetic, interdependent co-cultures to achieve concomitant utilization of chlorinated methanes as electron donors and organohalogens as electron acceptors. Specialized anaerobes conserve energy from the catabolic conversion of chloromethane or dichloromethane to formate, H2, and acetate, compounds that the organohalide-respiring bacterium Dehalogenimonas etheniformans strain GP requires to utilize cis-1,2-dichloroethenene and vinyl chloride as electron acceptors. Organism-specific qPCR enumeration matched the growth of individual dechlorinators to the respective functional (i.e. dechlorination) traits. The metabolite cross-feeding in the synthetic (co-)cultures enables concomitant utilization of chlorinated methanes (i.e. chloromethane and dichloromethane) and chlorinated ethenes (i.e. cis-1,2-dichloroethenene and vinyl chloride) without the addition of an external electron donor (i.e. formate and H2). The findings illustrate that naturally occurring chlorinated C1 compounds can sustain anaerobic food webs, an observation with implications for the development of interdependent, mutualistic communities, the sustenance of microbial life in oligotrophic and energy-deprived environments, and the fate of chloromethane/dichloromethane and chlorinated electron acceptors (e.g. chlorinated ethenes) in pristine environments and commingled contaminant plumes.
Topics: Coculture Techniques; Hydrocarbons, Chlorinated; Methane; Chloroflexi; Halogenation; Metabolic Networks and Pathways; Dichloroethylenes; Anaerobiosis
PubMed: 38818735
DOI: 10.1093/ismejo/wrae090 -
The Science of the Total Environment Aug 2024To investigate the effects of microplastics (MPs) on hydrolysis, acidification and microbial characteristics during waste activated sludge (WAS) anaerobic fermentation...
To investigate the effects of microplastics (MPs) on hydrolysis, acidification and microbial characteristics during waste activated sludge (WAS) anaerobic fermentation process, five different kinds of MPs were added into the WAS fermentation system and results indicated that, compared to the control group, the addition of polyvinyl chloride (PVC)-MPs exhibited the least inhibition on volatile fatty acids (VFAs), reducing them by 13.49 %. Conversely, polyethylene (PE)-MPs resulted in the greatest inhibition, with a reduction of 29.57 %. MPs, while accelerated the dissolution of WAS that evidenced by an increase of lactate dehydrogenase (LDH) release, concurrently inhibited the activities of relevant hydrolytic enzymes (α-Glucosidase, protease). For microbial mechanisms, MPs addition affected the proliferation of key microorganisms (norank_f_Bacteroidetes_vadinHA17, Ottowia, and Propioniclava) and reduced the abundance of genes associated with hydrolysis and acidification (pfkb, gpmI, ilvE, and aces). Additionally, MPs decreased the levels of key hydrolytic and acidogenic enzymes to inhibit hydrolysis and acidification processes. This research provides a basis for understanding and unveils impact mechanisms of the impact of MPs on sludge anaerobic fermentation.
Topics: Fermentation; Anaerobiosis; Waste Disposal, Fluid; Microplastics; Sewage; Metabolic Networks and Pathways; Water Pollutants, Chemical; Fatty Acids, Volatile; Microbiota; Bioreactors
PubMed: 38815824
DOI: 10.1016/j.scitotenv.2024.173518 -
The Journal of Parasitology May 2024Alveolar echinococcosis is considered to be one of the most potentially lethal parasitic zoonotic diseases. However, the molecular mechanisms by which Echinococcus...
Alveolar echinococcosis is considered to be one of the most potentially lethal parasitic zoonotic diseases. However, the molecular mechanisms by which Echinococcus multilocularis interacts with hosts are poorly understood, hindering the prevention and treatment of this disease. Due to the great advantages of cell culture systems for molecular research, numerous attempts have been made to establish primary cell cultures for E. multilocularis. In this study we developed a simple, rapid, and economical method that allows E. multilocularis metacestode tissue blocks to generate daughter vesicles without the continuous presence of host feeder cells in a regular medium. We performed anaerobic, hypoxic (1% O2), normoxic, and semi-anaerobic (in sealed tubes) cultures and found that E. multilocularis metacestode tissues can produce daughter vesicles only in the sealed tubes after 4 wk of incubation. The daughter vesicles cultivated in this system were remarkably enlarged under anaerobic conditions after 8 days of culture, whereas vesicles cultured under hypoxic (1% O2) and normoxic conditions showed only a mild increase in volume. Our in vitro cultivated vesicles showed strong viability and could be used to test antiparasitic drugs, isolate primary cells, and infect animals.
Topics: Animals; Echinococcus multilocularis; Echinococcosis; Mice; Anaerobiosis; Cell Culture Techniques
PubMed: 38811020
DOI: 10.1645/23-100 -
Environmental Research Sep 2024The conversion of carbon dioxide (CO) to methane (CH) is a strategy for sequestering CO. Zero-valent iron (ZVI) has been proposed as an alternative electron donor for...
The conversion of carbon dioxide (CO) to methane (CH) is a strategy for sequestering CO. Zero-valent iron (ZVI) has been proposed as an alternative electron donor for the CO reduction to CH. In this study, the effects of ZVI concentrations on the abiotic production of H (without the action of microorganisms) in the first part and on the biological conversion of CO to CH using ZVI as a direct electron donor in the second part were examined. In the abiotic H production, the increase in the ZVI concentration from 16 to 32, 64, and 96 g/L was found to have positive effects on both the amounts of H generated and the rates of H production because the extent of ZVI oxidation positively correlates with increasing surface area. Nevertheless, the increase in ZVI concentration from 96 to 224 g/L did not benefit the H production because the ZVI dissolution was suppressed by the increasing aqueous pH above 10. In the bioconversion of CO to CH using ZVI as an electron donor, the main methanogenesis pathway occurred via hydrogenotrophic methanogenesis at pH 8.7-9.5 driven by the genus Methanobacterium of the class Methanobacteria. At ZVI concentrations of 64 g/L and above, the production of volatile fatty acid (VFA) became clear. Acetate was the main VFA, indicating the induction of homoacetogenesis at ZVI concentrations of 64 g/L and above. In addition, the presence of propionate as the second major VFA suggests the production of propionate from CO and acetate under conditions with high H partial pressure. The results indicated that the pathway for ZVI/CO conversion to CH was competitive between hydrogenotrophic methanogenesis and homoacetogenesis.
Topics: Methane; Carbon Dioxide; Anaerobiosis; Iron; Hydrogen
PubMed: 38810832
DOI: 10.1016/j.envres.2024.119230 -
Journal of Environmental Sciences... Oct 2024Humic acid (HA) is a typical refractory organic matter, so it is of great significance to investigate its effect on the performance of Anammox granular sludge. When the...
Humic acid (HA) is a typical refractory organic matter, so it is of great significance to investigate its effect on the performance of Anammox granular sludge. When the dosage of HA ≤ 50 mg/L, HA promotes the total nitrogen removal rate (NRR) to 1.45 kg/(m·day). When HA was between 50 and 100 mg/L, the NRR of Anammox was stable. At this time, the adsorption of HA causes the sludge to gradually turn from red to brown, but the activities of heme and enzymes showed that its capacity was not affected. When HA levels reached 250 mg/L, the NRR dropped to 0.11 kg/(m·day). Moderate HA levels promoted the release of extracellular polymeric substance (EPS), but excessive HA levels lead to a decrease in EPS concentrations. HA inhibited Anammox activity, which indirectly hindered the transmission of substrate and accumulated substrate toxicity. Although HA promoted the increase of heterotrophic microbial abundance in Anammox system, the microbial diversity decreased gradually. With the increase of HA concentration, the abundance of Candidatus_Brocadia, the main functional microorganism of Anammox system, decreased gradually, while the abundance of Candidatus_Kuenenia increased gradually.
Topics: Humic Substances; Sewage; Nitrogen; Waste Disposal, Fluid; Bioreactors; Microbiota; Anaerobiosis
PubMed: 38802226
DOI: 10.1016/j.jes.2023.08.038 -
Bioresource Technology Jul 2024Sulfate-dependent ammonium oxidation (Sulfammox) is a critical process linking nitrogen and sulfur cycles. However, the metabolic pathway of microbes driven Sulfammox is...
Sulfate-dependent ammonium oxidation (Sulfammox) is a critical process linking nitrogen and sulfur cycles. However, the metabolic pathway of microbes driven Sulfammox is still in suspense. The study demonstrated that ammonium was not consumed with sulfate as the sole electron acceptor during long-term enrichment, probably due to inhibition from sulfide accumulation, while ammonium was removed at ∼ 10 mg N/L/d with sulfate and nitrate as electron acceptors. Ammonium and sulfate were converted into nitrogen gas, sulfide, and elemental sulfur. Sulfammox was mainly performed by Candidatus Brocadia sapporoensis and Candidatus Brocadia fulgida, both of which encoded ammonium oxidation pathway and dissimilatory sulfate reduction pathway. Not sulfide-driven autotrophic denitrifiers but Candidatus Kuenenia stuttgartiensis converted nitrate to nitrite with sulfide. The results of this study reveal the specialized metabolism of Sulfammox bacteria (Candidatus Brocadia sapporoensis and Candidatus Brocadia fulgida) and provide insight into microbial relationships during the nitrogen and sulfur cycles.
Topics: Oxidation-Reduction; Sulfur; Sulfates; Nitrogen; Anaerobiosis; Ammonium Compounds; Nitrates; Sulfides
PubMed: 38801958
DOI: 10.1016/j.biortech.2024.130903 -
Bioresource Technology Jul 2024This study applied granular activated carbon (GAC) to improve the anaerobic digestion of long-chain fatty acid (LCFA). New kinetics were considered to describe the...
This study applied granular activated carbon (GAC) to improve the anaerobic digestion of long-chain fatty acid (LCFA). New kinetics were considered to describe the effect of GAC on the LCFA degradation, including i) The adsorption kinetics of GAC for LCFA, ii) The β-oxidation pathway of LCFA, iii) The attached biomass improved by direct interspecies electron transfer (DIET). The developed model simulated the anaerobic digestion of stearic acid, palmitic acid, myristic acid, and lauric acid with 1.00 and 2.00 g l of GAC. The simulation results suggested that adding GAC led to the increase of k and k. As the concentration of GAC increased, the values of kinetic parameters increased while the accumulated acetate concentration decreased. Thus, GAC improved the kinetic parameters of the attached syntrophic communities.
Topics: Kinetics; Anaerobiosis; Fatty Acids; Adsorption; Charcoal; Electron Transport; Biomass; Computer Simulation; Biodegradation, Environmental
PubMed: 38801955
DOI: 10.1016/j.biortech.2024.130902 -
Journal of Mathematical Biology May 2024Decline of the dissolved oxygen in the ocean is a growing concern, as it may eventually lead to global anoxia, an elevated mortality of marine fauna and even a mass...
Decline of the dissolved oxygen in the ocean is a growing concern, as it may eventually lead to global anoxia, an elevated mortality of marine fauna and even a mass extinction. Deoxygenation of the ocean often results in the formation of oxygen minimum zones (OMZ): large domains where the abundance of oxygen is much lower than that in the surrounding ocean environment. Factors and processes resulting in the OMZ formation remain controversial. We consider a conceptual model of coupled plankton-oxygen dynamics that, apart from the plankton growth and the oxygen production by phytoplankton, also accounts for the difference in the timescales for phyto- and zooplankton (making it a "slow-fast system") and for the implicit effect of upper trophic levels resulting in density dependent (nonlinear) zooplankton mortality. The model is investigated using a combination of analytical techniques and numerical simulations. The slow-fast system is decomposed into its slow and fast subsystems. The critical manifold of the slow-fast system and its stability is then studied by analyzing the bifurcation structure of the fast subsystem. We obtain the canard cycles of the slow-fast system for a range of parameter values. However, the system does not allow for persistent relaxation oscillations; instead, the blowup of the canard cycle results in plankton extinction and oxygen depletion. For the spatially explicit model, the earlier works in this direction did not take into account the density dependent mortality rate of the zooplankton, and thus could exhibit Turing pattern. However, the inclusion of the density dependent mortality into the system can lead to stationary Turing patterns. The dynamics of the system is then studied near the Turing bifurcation threshold. We further consider the effect of the self-movement of the zooplankton along with the turbulent mixing. We show that an initial non-uniform perturbation can lead to the formation of an OMZ, which then grows in size and spreads over space. For a sufficiently large timescale separation, the spread of the OMZ can result in global anoxia.
Topics: Animals; Oxygen; Zooplankton; Models, Biological; Phytoplankton; Computer Simulation; Oceans and Seas; Plankton; Mathematical Concepts; Ecosystem; Seawater; Food Chain; Anaerobiosis
PubMed: 38801565
DOI: 10.1007/s00285-024-02107-7 -
Reproduction in Domestic Animals =... May 2024This study investigated the effects of storage conditions on the quality of chilled ram semen stored at 4°C for 48 h, comparing aerobic and anaerobic conditions....
This study investigated the effects of storage conditions on the quality of chilled ram semen stored at 4°C for 48 h, comparing aerobic and anaerobic conditions. Ejaculates from INRA180 rams were collected and stored under both conditions, with assessments at 0-, 24-, and 48-h intervals. Various sperm parameters were examined, including motility, velocity, viability, morphology, membrane integrity, and lipid peroxidation. Results showed that storage duration significantly impacted sperm quality, leading to a gradual decline from 0 to 24 h and 24 to 48 h. Notably, after the initial 24 h, progressive motility (PM) and membrane integrity (MI) demonstrated distinct responses to storage conditions. Anaerobic storage consistently improved PM and MI values compared to aerobic storage between 24 and 48 h. Anaerobic conditions also enhanced viability and reduced abnormality at the 48-h mark. Total motility remained stable throughout storage. Velocity parameters (VCL: curvilinear velocity; VSL: straight velocity and VAP: velocity average path) exhibited differences between the 24- and 48-h intervals, with anaerobic storage resulting in higher VAP and VSL values. Moreover, lipid peroxidation exhibited a progressive increase from 0 to 24 h and 24 to 48 h, independent of storage conditions. Remarkably, anaerobic storage consistently yielded lower lipid peroxidation levels compared to aerobic storage, regardless of storage duration. In conclusion, this study highlights that the anaerobic storage proved advantageous for chilled ram semen quality, particularly after the initial 24 h.
Topics: Semen Preservation; Animals; Male; Lipid Peroxidation; Oxygen; Sperm Motility; Semen Analysis; Spermatozoa; Anaerobiosis; Sheep, Domestic; Sheep; Semen; Cell Survival
PubMed: 38798164
DOI: 10.1111/rda.14618