Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.199
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-34639670

RESUMEN

Oxygen production in cryogenic air separation units is related to a significant carbon footprint and its supply in the medicinal sphere became critical during the recent COVID-19 crisis. An improved unit design was proposed, utilizing a part of waste heat produced during air pre-cooling and intercooling via absorption coolers, to reduce power consumption. Variable ambient air humidity impact on compressed air dryers' regeneration was also considered. A steady-state process simulation of a model 500 t h-1 inlet cryogenic air separation unit was performed in Aspen Plus® V11. Comparison of a model without and with absorption coolers yielded an achievable reduction in power consumption for air compression and air dryer regeneration by 6 to 9% (23 to 33 GWh year-1) and a favorable simple payback period of 4 to 10 years, both depending on air pressure loss in additional heat exchangers to be installed. The resulting specific oxygen production decrease amounted to EUR 2-4.2 t-1. Emissions of major gaseous pollutants from power production were both calculated by an in-house developed thermal power plant model and adopted from literature. A power consumption cut was translated into the following annual greenhouse gas emission reduction: CO2 16 to 30 kilotons, CO 0.3 to 2.3 tons, SOx 4.7 to 187 tons and NOx 11 to 56 tons, depending on applied fossil fuel-based emission factors. Considering a more renewable energy sources-containing energy mix, annual greenhouse gas emissions decreased by 50 to over 80%, varying for individual pollutants.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , COVID-19 , Gases de Efecto Invernadero , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Efecto Invernadero , Calor , Humanos , Oxígeno , SARS-CoV-2
2.
J Environ Manage ; 300: 113836, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34649322

RESUMEN

Trade has been substantially influencing regional economic development, environmental sustainability, and human well-being. Enabled by the decomposition analysis, pollution haven hypothesis or "no-trade" scenarios (NTSs), the effects of trade on global/national social-economic-environmental development have been revealed. However, major limitations (e.g., using with-trade economic structures or neglecting price differences) existed in previous studies, and thus made the previous assessments of trade's effects unsatisfactorily. This study develops a novel NTS that addresses the existing limitations, and further applies it to estimate the effect of trade on global economic development and greenhouse gas (GHG) emissions. We show that current international trade benefits the global economic growth but with a consequence of more GHG emissions compared with the NTS. The hypothetical production in small countries (e.g., Luxembourg or Japan) would be more constrained by the production factors (e.g., land) under the NTS, compared with those factor-endowment countries (e.g., the United States or India). For country-specific analysis, we find that today's developed countries would have a substantial increase in their GHG emissions of clothing- and service-related products under the NTS, whereas countries with net-export (e.g., China or Brazil) would have less GHG emissions under the NTS. Enhancing future global collaborations is vital, especially for small or resource-deficient economies, if they are to achieve the Sustainable Development Goals.


Asunto(s)
Gases de Efecto Invernadero , Dióxido de Carbono/análisis , Comercio , Desarrollo Económico , Efecto Invernadero , Humanos , Internacionalidad
3.
Sci Total Environ ; 792: 148161, 2021 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-34465063

RESUMEN

Paludiculture, the cultivation of crops on rewetted peatlands, is often proposed as a viable climate change mitigation option that reduces greenhouse gas emissions (GHGe), while simultaneously providing novel agricultural business options. In West Europe, experiments are ongoing in using the paludicrop cattail (Typha spp.) as feedstock for insulation panel material. Here, we use a Dutch case study to investigate the environmental potential and economic viability of shifting the use of peat soils from grassland (for dairy production) to Typha paludiculture (for cultivation and insulation panel production). Using a life cycle assessment and cost-benefit analysis, we compared the global warming potential (GWP), yearly revenues and calculated Net Present Value (NPV) of 1 ha Dutch peat soil used either for dairy production or for Typha paludiculture. We estimated that changing to Typha paludiculture leads to a GWP reduction of ~32% (16.4 t CO2-eq ha-1), mainly because of lower emissions from peat decomposition as a result of land-use management (-21.6 t CO2-eq ha-1). If biogenic carbon storage is excluded, the avoided impact of conventional insulation material is insufficient to compensate the impact of cultivating and processing Typha (9.7 t CO2-eq ha-1); however, this changes if biogenic carbon storage is included (following PAS2050 guidelines). Typha paludiculture is currently not competitive with dairy production, mainly due to high cultivation costs and low revenues, which are both uncertain, and will likely improve as the system develops. Its NPV is negative, mainly due to high investment costs. This can be improved by introducing carbon credits, with carbon prices for Typha paludiculture (30 years) comparable to EU-ETS prices. In conclusion, Dutch Typha paludiculture has a significant climate change mitigation potential by reducing emissions from deep drained peatlands. Nevertheless, attention is needed to increase its economic viability as this is a key aspect of the system change.


Asunto(s)
Gases de Efecto Invernadero , Typhaceae , Agricultura , Dióxido de Carbono/análisis , Gases de Efecto Invernadero/análisis , Suelo , Humedales
4.
Sci Total Environ ; 792: 148479, 2021 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-34465066

RESUMEN

This review paper aims to identify the main sources of carbon dioxide (CO2) emissions from wastewater treatment plants (WWTPs) and highlights the technologies developed for CO2 capture in this milieu. CO2 is emitted in all the operational units of conventional WWTPs and even after the disposal of treated effluents and sludges. CO2 emissions from wastewater can be captured or mitigated by several technologies such as the production of biochar from sludge, the application of constructed wetlands (CWs), the treatment of wastewater in microbial electrochemical processes (microbial electrosynthesis, MES; microbial electrolytic carbon capture, MECC; in microbial carbon capture, MCC), and via microalgal cultivation. Sludge-to-biochar and CW systems showed a high cost-effectiveness in the capture of CO2, while MES, MECC, MCC technologies, and microalgal cultivation offered efficient capture of CO2 with associate production of value-added by-products. At the state-of-the-art, these technologies, utilized for carbon capture and utilization from wastewater, require more research for further configuration, development and cost-effectiveness. Moreover, the integration of these technologies has a potential internal rate of return (IRR) that could equate the operation or provide additional revenue to wastewater management. In the context of circular economy, these carbon capture technologies will pave the way for new sustainable concepts of WWTPs, as an essential element for the mitigation of climate change fostering the transition to a decarbonised economy.


Asunto(s)
Gases de Efecto Invernadero , Dióxido de Carbono/análisis , Electrólisis , Gases de Efecto Invernadero/análisis , Aguas Residuales , Humedales
5.
J Anim Sci ; 99(10)2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34586401

RESUMEN

The objective of this project was to determine the impact of feeding growing pigs with high wheat millrun diets supplemented with a multi-carbohydrase enzyme (amylase, cellulase, glucanase, xylanase, and invertase activities) on nutrient digestibility, growth performance, and greenhouse gas (GHG) output (carbon dioxide, CO2; nitrous oxide, N2O; methane, CH4). Three experiments were conducted utilizing six treatments arranged as a 3 × 2 factorial (0%, 15%, or 30% wheat millrun; with or without enzyme) for the digestibility experiment or as a 2 × 2 factorial (0% or 30% wheat millrun; with or without enzyme) for the performance and GHG experiments. The digestibility, performance, and GHG experiments utilized 48 individually housed pigs, 180 pigs housed 5 per pen, or 96 pigs housed 6 per chamber, respectively. Increasing wheat millrun up to 30% in the diet of growing pigs resulted in decreased energy, nitrogen (N) and phosphorus (P) apparent total tract digestibility and net energy content (P < 0.01). Overall, average daily gain (ADG) and gain to feed ratio were reduced in pigs fed wheat millrun (P < 0.05). Enzyme supplementation had minimal effects on the digestibility or performance parameters measured. Feeding diets with 30% millrun did not affect GHG output (CH4: 4.7 and 4.9; N2O: 0.45 and 0.42; CO2: 1,610 and 1,711 mg/s without or with millrun inclusion, respectively; P > 0.78). Enzyme supplementation had no effect on GHG emissions (CH4: 4.5 and 5.1; N2O: 0.46 and 0.42; CO2: 1,808 and 1,513 mg/s without or with enzymes, respectively; P > 0.51). Overall, the carbohydrase enzyme had minimal effects on parameters measured, regardless of wheat millrun inclusion (P > 0.10). Although energy, N and P digestibility, and ADG were reduced, the inclusion of up to 30% wheat millrun in the diet has no effect on GHG emissions from growing pigs (P > 0.10).


Asunto(s)
Gases de Efecto Invernadero , Triticum , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Suplementos Dietéticos , Digestión , Glicósido Hidrolasas , Porcinos
6.
J Anim Sci ; 99(10)2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34586400

RESUMEN

Ruminant supply chains contribute 5.7 gigatons of CO2-eq per annum, which represents approximately 80% of the livestock sector emissions. One of the largest sources of emission in the ruminant sector is methane (CH4), accounting for approximately 40% of the sectors total emissions. With climate change being a growing concern, emphasis is being put on reducing greenhouse gas emissions, including those from ruminant production. Various genetic and environmental factors influence cattle CH4 production, such as breed, genetic makeup, diet, management practices, and physiological status of the host. The influence of genetic variability on CH4 yield in ruminants indicates that genomic selection for reduced CH4 emissions is possible. Although the microbiology of CH4 production has been studied, further research is needed to identify key differences in the host and microbiome genomes and how they interact with one another. The advancement of "-omics" technologies, such as metabolomics and metagenomics, may provide valuable information in this regard. Improved understanding of genetic mechanisms associated with CH4 production and the interaction between the microbiome profile and host genetics will increase the rate of genetic progress for reduced CH4 emissions. Through a systems biology approach, various "-omics" technologies can be combined to unravel genomic regions and genetic markers associated with CH4 production, which can then be used in selective breeding programs. This comprehensive review discusses current challenges in applying genomic selection for reduced CH4 emissions, and the potential for "-omics" technologies, especially metabolomics and metagenomics, to minimize such challenges. The integration and evaluation of different levels of biological information using a systems biology approach is also discussed, which can assist in understanding the underlying genetic mechanisms and biology of CH4 production traits in ruminants and aid in reducing agriculture's overall environmental footprint.


Asunto(s)
Gases de Efecto Invernadero , Metano , Animales , Bovinos/genética , Metabolómica , Metagenómica , Metano/análisis , Rumiantes/genética
7.
Nature ; 597(7876): 360-365, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34526707

RESUMEN

Fish and other aquatic foods (blue foods) present an opportunity for more sustainable diets1,2. Yet comprehensive comparison has been limited due to sparse inclusion of blue foods in environmental impact studies3,4 relative to the vast diversity of production5. Here we provide standardized estimates of greenhouse gas, nitrogen, phosphorus, freshwater and land stressors for species groups covering nearly three quarters of global production. We find that across all blue foods, farmed bivalves and seaweeds generate the lowest stressors. Capture fisheries predominantly generate greenhouse gas emissions, with small pelagic fishes generating lower emissions than all fed aquaculture, but flatfish and crustaceans generating the highest. Among farmed finfish and crustaceans, silver and bighead carps have the lowest greenhouse gas, nitrogen and phosphorus emissions, but highest water use, while farmed salmon and trout use the least land and water. Finally, we model intervention scenarios and find improving feed conversion ratios reduces stressors across all fed groups, increasing fish yield reduces land and water use by up to half, and optimizing gears reduces capture fishery emissions by more than half for some groups. Collectively, our analysis identifies high-performing blue foods, highlights opportunities to improve environmental performance, advances data-poor environmental assessments, and informs sustainable diets.


Asunto(s)
Acuicultura , Ecosistema , Monitoreo del Ambiente , Alimentos Marinos , Desarrollo Sostenible , Animales , Acuicultura/tendencias , Cambio Climático , Dieta , Ecología , Política Ambiental , Explotaciones Pesqueras , Abastecimiento de Alimentos/métodos , Gases de Efecto Invernadero , Humanos , Moluscos , Nitrógeno , Fósforo , Alimentos Marinos/provisión & distribución , Algas Marinas , Desarrollo Sostenible/tendencias
8.
Horm Metab Res ; 53(9): 575-587, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34496408

RESUMEN

Global warming and the rising prevalence of obesity are well described challenges of current mankind. Most recently, the COVID-19 pandemic arose as a new challenge. We here attempt to delineate their relationship with each other from our perspective. Global greenhouse gas emissions from the burning of fossil fuels have exponentially increased since 1950. The main contributors to such greenhouse gas emissions are manufacturing and construction, transport, residential, commercial, agriculture, and land use change and forestry, combined with an increasing global population growth from 1 billion in 1800 to 7.8 billion in 2020 along with rising obesity rates since the 1980s. The current Covid-19 pandemic has caused some decline in greenhouse gas emissions by limiting mobility globally via repetitive lockdowns. Following multiple lockdowns, there was further increase in obesity in wealthier populations, malnutrition from hunger in poor populations and death from severe infection with Covid-19 and its virus variants. There is a bidirectional relationship between adiposity and global warming. With rising atmospheric air temperatures, people typically will have less adaptive thermogenesis and become less physically active, while they are producing a higher carbon footprint. To reduce obesity rates, one should be willing to learn more about the environmental impact, how to minimize consumption of energy generating carbon dioxide and other greenhouse gas emissions, and to reduce food waste. Diets lower in meat such as a Mediterranean diet, have been estimated to reduce greenhouse gas emissions by 72%, land use by 58%, and energy consumption by 52%.


Asunto(s)
Cambio Climático , Obesidad/etiología , Agricultura/economía , Agricultura/tendencias , COVID-19/complicaciones , COVID-19/epidemiología , COVID-19/patología , Cambio Climático/historia , Comorbilidad , Disruptores Endocrinos/toxicidad , Ambiente , Exposición a Riesgos Ambientales/historia , Exposición a Riesgos Ambientales/estadística & datos numéricos , Gases de Efecto Invernadero/toxicidad , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Obesidad/epidemiología , Obesidad/metabolismo , Pandemias , Factores de Riesgo
9.
Chimia (Aarau) ; 75(9): 788-799, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34526185

RESUMEN

In today's societies, climate-damaging and finite fossil resources such as oil and natural gas serve a dual purpose as energy source and as carbon source for chemicals and plastics. To respond to the finite availability and to meet international climate goals, a change to a renewable energy and raw material basis is inevitable and represents a highly complex task. In this review, we assess possible technology paths for Switzerland to reach these goals. First, we provide an overview of Switzerland's current energy demand and discuss possible renewable technologies as well as proposed scenarios to defossilize the current energy system. In here, electric vehicles and heat pumps are key technologies, whereas mainly photovoltaics replace nuclear power to deliver clean electricity. The production of chemicals also consumes fossil resources and for Switzerland, the oil demand for imported domestically used chemicals and plastics corresponds to around 20% of the current energetic oil demand. Thus, we additionally summarize technologies and visions for a sustainable chemical sector based on the renewable carbon sources biomass, CO2 and recycled plastic. As biomass is the most versatile renewable energy and carbon source, although with a limited availability, aspects and proposed strategies for an optimal use are discussed.


Asunto(s)
Gases de Efecto Invernadero , Dióxido de Carbono/análisis , Electricidad , Fuentes Generadoras de Energía , Suiza
10.
J Environ Manage ; 300: 113746, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34562822

RESUMEN

Greenhouse gas emissions from power plants that use fossil fuels cause a serious impact to the environment, for this reason the use of renewable energy technologies is an important alternative as a way of combatting climate change. The production of power via biomass is considered as a carbon neutral energy resource, but it is well known that the non-fossil CO2 emitted from this type of processes can also be captured. In order to do so, in this work it is proposed a match between a Biogas combined cycle power plant and postcombustion carbon capture process, to capture the CO2 produced by the biogas combustion, and also it considered a match with an organic Rankine cycle that uses the wasted energy of the combustion gases. Additionally, it is considered that the captured carbon is used to produce some value-added chemicals and fuels. Environmental and energetic evaluations were carried out for the coupling of those technologies. The implementation of the carbon capture plant, results on a diminution of the 87% of the emission of the combined cycle power plant. The life cycle analysis results show that the study case of Syngas production via dry reforming of methane, presents the lower global warming potential (0.088 CO2-eq kg/kg) and it was also found that the global warming potential has a reduction with the help of the mass integration between the different alternatives of CO2 utilization. Finally, it was found an annual reduction of 0.055 CO2-eq t for the system with mass integration compared with the cases without mass integration.


Asunto(s)
Biocombustibles , Dióxido de Carbono , Carbono , Dióxido de Carbono/análisis , Efecto Invernadero , Centrales Eléctricas
11.
J Environ Manage ; 300: 113698, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34530365

RESUMEN

This study aimed to quantify greenhouse gas emissions derived from the production-consumption of rice in Hubei-a major rice-producing province in central China. This research employed primary and secondary data collection methods. Primary data sources included interviews and experimental observations from seven counties in Hubei collected from June 2016 to December 2016. Secondary data sources-including national datasets, inter-governmental reports, and peer-reviewed articles-were used to extract relevant data, such as emission factors, and national and provincial rice output. Life Cycle Assessment was employed to build a comprehensive inventory and map of the rice carbon footprint, including the following five stages: production inputs, farm management, growth period, processing and sale, and consumption. Uncertainty analysis was performed to validate the reliability of carbon footprint estimations. Results showed that the carbon footprint for every 1 ton of polished rice in Hubei ranged between 4.19-6.81 t CO2e/t and was 5.39 t CO2e/t on average. Greenhouse gas emissions were primarily produced from rice fields during the growth stage (over 60% of greenhouse gas emissions of the whole life cycle of rice), followed by the consumption stage, and the production and transportation of agricultural inputs. Uncertainty analysis estimations indicated acceptable levels of reliability. This study's results indicate that the production and consumption of rice is a significant contributor to agricultural carbon emissions in Hubei-consistent with national estimates that place China as the largest carbon dioxide emitter globally. This research provides further insight into future policies and targeted initiatives for the efficient use of low-carbon agricultural inputs for rice production and consumption stages in China.


Asunto(s)
Agricultura , Huella de Carbono , Oryza , China , Efecto Invernadero , Oryza/crecimiento & desarrollo , Reproducibilidad de los Resultados , Incertidumbre
12.
Environ Sci Technol ; 55(19): 13174-13185, 2021 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-34542993

RESUMEN

On-demand ridesourcing services from transportation network companies (TNCs), such as Uber and Lyft, have reshaped urban travel and changed externality costs from vehicle emissions, congestion, crashes, and noise. To quantify these changes, we simulate replacing private vehicle travel with TNCs in six U.S. cities. On average, we find a 50-60% decline in air pollutant emission externalities from NOx, PM2.5, and VOCs due to avoided "cold starts" and relatively newer, lower-emitting TNC vehicles. However, increased vehicle travel from deadheading creates a ∼20% increase in fuel consumption and associated greenhouse gas emissions and a ∼60% increase in external costs from congestion, crashes, and noise. Overall, shifting private travel to TNCs increases external costs by 30-35% (adding 32-37 ¢ of external costs per trip, on average). This change in externalities increases threefold when TNCs displace transit or active transport, drops by 16-17% when TNC vehicles are zero-emission electric, and potentially results in reduced externalities when TNC rides are pooled.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Gases de Efecto Invernadero , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Contaminación del Aire/prevención & control , Análisis Costo-Beneficio , Emisiones de Vehículos/análisis
13.
J Anim Sci ; 99(10)2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34586403
14.
Rev Sci Tech ; 40(2): 431-438, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34542104

RESUMEN

Climate change due to increasing greenhouse gas (GHG) emissions is one of the most pressing issues facing society on a global scale. The growth of GHG emissions between 2000 and 2010 was higher than in each of the previous three decades, and each of the past four decades has been successively warmer than any preceding decades since 1850. Continued GHG emissions will cause further warming and changes in the climate system. Climate change affects livestock production in multiple ways, both directly and indirectly. Many of the impacts on the livestock sector result from increasing frequency and magnitude of weather and climate extremes such as droughts, flash floods, untimely rains, frost, hail and severe storms. This article describes some of the most vulnerable disaster communities in Asia, Africa, Australia, Europe and South America. It then describes the importance of meteorological information provided by national Meteorological and Hydrological Services to help Veterinary Services support sustainable management of livestock in vulnerable pastoral communities.


Asunto(s)
Desastres , Gases de Efecto Invernadero , Animales , Cambio Climático , Sequías , Efecto Invernadero , Ganado
15.
Rev Sci Tech ; 40(2): 421-430, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34542106

RESUMEN

Climate change due to increasing greenhouse gas (GHG) emissions is one of the most pressing issues facing society on a global scale. The growth of GHG emissions between 2000 and 2010 was higher than in each of the previous three decades, and each of the past four decades has been successively warmer than any preceding decades since 1850. Continued GHG emissions will cause further warming and changes in the climate system. Climate change affects livestock production in multiple ways, both directly and indirectly. Many of the impacts on the livestock sector result from increasing frequency and magnitude of weather and climate extremes such as droughts, flash floods, untimely rains, frost, hail and severe storms. This article describes some of the most vulnerable disaster communities in Asia, Africa, Australia, Europe and South America. It then describes the importance of meteorological information provided by national Meteorological and Hydrological Services to help Veterinary Services support sustainable management of livestock in vulnerable pastoral communities.


Asunto(s)
Desastres , Gases de Efecto Invernadero , Animales , Cambio Climático , Sequías , Efecto Invernadero , Ganado
16.
Nutrients ; 13(8)2021 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-34444667

RESUMEN

Low-carbon diets can counteract climate change and promote health if they are nutritionally adequate, affordable and culturally acceptable. This study aimed at developing sustainable diets and to compare these with the EAT-Lancet diet. The Swedish national dietary survey Riksmaten Adolescents 2016-2017 was used as the baseline. Diets were optimized using linear programming for four dietary patterns: omnivores, pescatarians, vegetarians and vegans. The deviation from the baseline Riksmaten diet was minimized for all optimized diets while fulfilling nutrient and climate footprint constraints. Constraining the diet-related carbon dioxide equivalents of omnivores to 1.57 kg/day resulted in a diet associated with a reduction of meat, dairy products, and processed foods and an increase in potatoes, pulses, eggs and seafood. Climate-friendly, nutritionally adequate diets for pescatarians, vegetarians and vegans contained fewer foods and included considerable amounts of fortified dairy and meat substitutes. The optimized diets did not align very well with the food-group pattern of the EAT-Lancet diet. These findings suggest how to design future diets that are climate-friendly, nutritionally adequate, affordable, and culturally acceptable for Swedish adolescents with different dietary patterns. The discrepancies with the EAT diet indicate that the cultural dietary context is likely to play an important role in characterizing sustainable diets for specific populations.


Asunto(s)
Cambio Climático , Dieta Saludable , Dieta Vegetariana , Valor Nutritivo , Carne Roja , Alimentos Marinos , Adolescente , Conducta del Adolescente , Fenómenos Fisiológicos Nutricionales de los Adolescentes , Factores de Edad , Huella de Carbono , Dieta Saludable/efectos adversos , Dieta Vegana , Ingestión de Energía , Conducta Alimentaria , Preferencias Alimentarias , Efecto Invernadero , Humanos , Estado Nutricional , Ingesta Diaria Recomendada , Carne Roja/efectos adversos , Alimentos Marinos/efectos adversos , Suecia
17.
Sci Total Environ ; 800: 149508, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34391143

RESUMEN

Greenhouse gas (GHG) emissions including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) created via wastewater treatment processes are not easily modeled given the non-linearity and complexity of biological processes. These factors are also impacted by limited data availability making the development of artificial data generation algorithms, such as a generative adversarial network (GAN), useful for determination of GHG emission rate estimates (EREs). The main objective of this study was to develop a hybrid approach of using GAN and regression modelling to determine GHG EREs from a cold-region biological nutrient removal (BNR) municipal wastewater treatment plant (MWTP) in which the aerobic reactor has previously been established as the main GHG emission source. To our knowledge, this is the first application of GAN used for MWTP modelling purposes. The EREs were generated from laboratory-scale reactors used in conjunction with facility-monitored operating parameters to develop the GAN and regression models. Results showed that regression models provided reasonable EREs using parameters including hydraulic retention time (HRT), temperature, total organic carbon, and dissolved oxygen (DO) concentrations for CO2 EREs; HRT, temperature, DO and phosphate (PO43-) concentrations for CH4 EREs; and temperature, DO, and nitrogen (nitrite, nitrate, and ammonium) concentrations for N2O EREs. Additionally, the addition of 100 GAN-created virtual data points improved regression model metrics including increased correlation coefficient and index agreement values, and decreased root mean square error values. Clearly, virtual data augmentation using GAN is a valuable resource in supplementation of limited data for improved modelling outcomes. Genetic algorithm optimization was also used to determine operating parameter modifications resulting in potential for minimization (or maximization) of GHG emissions.


Asunto(s)
Gases de Efecto Invernadero , Dióxido de Carbono/análisis , Efecto Invernadero , Gases de Efecto Invernadero/análisis , Metano/análisis , Óxido Nitroso/análisis , Aguas Residuales
18.
Sci Total Environ ; 800: 149551, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34392224

RESUMEN

Due to changes in the energy market, it is projected that lignite excavation will be reduced in the near future. Cessation of exploitation is associated with restitution of natural water conditions and flooding of the resources left in the mines. Flooded lignite mines are a potential source of greenhouse gases (GHG) (CH4, CO2 and N2O), which should be monitored due to growing environmental concerns. Here, we aim to recognize GHG release from the lignites collected from the main deposits of Poland, Slovenia and Serbia. GHG production was studied along with a range of physical and chemical parameters that are crucial for microbial growth and activity. The microcosm experiments showed that the main gas emitted from the lignites was carbon dioxide. Daily CO2 production was highly variable. The highest values were recorded for detroxylitic lignite collected from the Konin deposit (402.05 nmol CO2 g-1 day-1) while the lowest were for the Kolubara xylitic lignite (19.64 nmol CO2 g-1 day-1). Methane production was much lower and ranged from nearly zero to 66.75 nmol g dry mass-1 d-1. Nitrous oxide production was not detected. It was found that CO2 production, being a general measure of microbial activity, was positively affected by NO3- concentration and redox potential. With respect to methane formation, the lower atmospheric oxygen exposure of the sample from the Velenje underground mine compared to the samples from the opencast mines has been identified as a possible cause of the high methane production. The overall global warming potential (GWP) of the gases released by xylitic lignite was lowest among the samples. Preferential extraction of the detritic lignites is suggested as a means to reduce GHG emissions from the abandoned lignite mines.


Asunto(s)
Gases de Efecto Invernadero , Dióxido de Carbono/análisis , Carbón Mineral , Efecto Invernadero , Gases de Efecto Invernadero/análisis , Metano/análisis , Óxido Nitroso/análisis , Suelo
19.
Sci Total Environ ; 800: 149433, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34392227

RESUMEN

Greenhouse gases (GHGs) released from permafrost regions may have a positive feedback to climate change, but there is much uncertainty about additional warming from the permafrost carbon cycle. One of the main reasons for this uncertainty is that the observation data of large-scale GHG concentrations are sparse, especially for areas with rapid permafrost degradation. We selected the Mongolian Plateau as the study area. We first analyzed the active layer thickness and ground temperature changes using borehole observations. Based on ground observation data, we assessed the applicability of Greenhouse Gases Observing Satellite (GOSAT) carbon dioxide (CO2) and methane (CH4) datasets. Finally, we analyzed the temporal and spatial changes in near-surface CO2 and CH4 concentrations from 2010 to 2017 and their patterns in different permafrost regions. The results showed that the Mongolian permafrost has been experiencing rapid degradation. The annual average near-surface CO2 concentration increased gradually between 2.19 ppmv/yr and 2.38 ppmv/yr, whereas the near-surface CH4 concentration increased significantly from 7.76 ppbv/yr to 8.49 ppbv/yr. There were significant seasonal variations in near-surface CO2 and CH4 concentrations for continuous, discontinuous, sporadic, and isolated permafrost zones. The continuous and discontinuous permafrost zones had lower near-surface CO2 and CH4 concentrations in summer and autumn, whereas sporadic and isolated permafrost zones had higher near-surface CO2 and CH4 concentrations in winter and spring. Our results indicated that climate warming led to rapid permafrost degradation, and carbon-based GHG concentrations also increased rapidly in Mongolia. Although, GHG concentrations increased at rates similar to the global average and many factors can account for their changes, GHG concentration in the permafrost regions merits more attention in the future because the spatiotemporal distribution has indicated a different driving force for regional warming.


Asunto(s)
Gases de Efecto Invernadero , Hielos Perennes , Dióxido de Carbono/análisis , Cambio Climático , Metano/análisis
20.
Bioresour Technol ; 340: 125713, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34371335

RESUMEN

The aim of current work was to explore the impact of Cornstalk (CS) on greenhouse gaseous emission and maturation during further composting and analyzed its impact on bacterial diversity. Three kinds of immature fertilizers were collected from chicken, pig and dairy manure namely T1, T2 and T3 as control, T4, T5 and T6 were added CS into T1 to T3 and adjusted C/N to 25 namely treatment. The results illustrated that gases (N2O, CH4 and NH3) emission of CS added treatments decreased by 6.39%-24.68%, 10.60%-23.23% and 13.00%-19.58%, respectively. But the CS amendment increased CO2 emission by 15.53%-30.81%. The mineralization of carbon and nitrogen was mainly correlated to Firmicutes, Actinobacteria, Proteobacteria and Bacteroidota, CS amendment increased abundance by 22.28%, 17.79%, 1.48% and 35.90%, respectively. The strategy of employing CS would be the most feasible approach for recycling of immature manure, considering its compost quality and environmental from farm.


Asunto(s)
Compostaje , Gases de Efecto Invernadero , Animales , Gases , Estiércol , Nitrógeno/análisis , Suelo , Porcinos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...