Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 544
Filtrar
1.
J Environ Manage ; 259: 109782, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32072951

RESUMO

The steel industry is the largest consumer of energy in the world among industrial sectors. It is generally acknowledged that energy and environment are intimately related. Steel production is an energy intensive process that has a significant environmental impact. This paper reviews the progress made on energy consumption, carbon dioxide emissions and water consumption in the steel industry worldwide. The reduction in the availability of fresh water resources combined with the effects of global warming and climate change have increased pressure on industries, especially steel, to reduce its overall pollution, and specifically its water and carbon footprint. The implications of these effects on the value chain is discussed in this review. The contribution of new emerging technologies of iron and steelmaking is also reviewed. Finally, the important issues that contribute to define a sustainable industrial activity such as the recycling of steel and of by-products of steel production are studied. The history of steel industry is full of lessons, one of which is the need to keep the dreams alive. There are indeed expectations to solve problems created by technical progress.


Assuntos
Indústrias , Aço , Pegada de Carbono , Poluição Ambiental , Recursos Hídricos
2.
Bioresour Technol ; 300: 122647, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31891853

RESUMO

This work aimed to compare the carbon footprint (CF) of six full-scale wastewater treatment plants (WWTPs). The CF was estimated in the range of 23-100 kg CO2e per population equivalent. In the total CF, the direct emissions held the highest share (62-74%) for the plants with energy recovery from biogas. In the plants depending entirely on the power grid, the indirect emissions due to energy consumption dominated the total CF (69-72%). The estimated CF was found highly sensitive towards the choice of N2O emission factors. A dual effect of external substrates co-digestion on the CF has been presented. After co-digestion, the overall CF decreased by 7% while increasing the biogas production by 17%. While applying the empirical model, the level of energy neutrality was strongly related to the ratio of the indirect to direct emissions.


Assuntos
Pegada de Carbono , Águas Residuárias , Eliminação de Resíduos Líquidos
4.
J Environ Manage ; 250: 109363, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31703242

RESUMO

The past two decades have witnessed growing global concern about excessive greenhouse gas (GHG) emissions by reservoirs and the development of hydropower. Literature review showed that life cycle GHG emissions per energy production of collected global dataset ranged from 0.04 to 237.0 gCO2eq/kW⋅h, with a mean of 25.8 ±â€¯3.0 gCO2eq/kW⋅h. Synthesis from the China's five largest hydro-projects and other publications estimated that the large- and mid-scale hydro-projects in China had a carbon footprint between 6.2 gCO2eq/kWh and 34.6 gCO2eq/kWh, with a mean value of 19.2 ±â€¯6.8 gCO2eq/kWh (mean ±â€¯sd.). Over 80% of the carbon footprint of the hydro-projects could be conservatively allocated to hydroelectricity generation, while the rest could then be allocated to flood control services. In the Three Gorges Dam Project, the allocated life cycle GHG emissions per energy production of its hydroelectricity production was estimated to be 17.8 gCO2eq/kW⋅h. GHG emissions from reservoir sediments and in the phase of operation and maintenance were still uncertain. There is still a need of in-depth research on reservoir carbon cycling to quantify net reservoir GHG emissions.


Assuntos
Pegada de Carbono , Gases de Efeito Estufa , China , Inundações , Efeito Estufa
5.
Environ Sci Technol ; 53(23): 13598-13606, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31746188

RESUMO

This study estimates the environmental impact of mining Bitcoin, the most well-known blockchain-based cryptocurrency, and contributes to the discussion on the technology's supposedly large energy consumption and carbon footprint. The lack of a robust methodological framework and of accurate data on key factors determining Bitcoin's impact have so far been the main obstacles in such an assessment. This study applied the well-established Life Cycle Assessment methodology to an in-depth analysis of drivers of past and future environmental impacts of the Bitcoin mining network. It was found that, in 2018, the Bitcoin network consumed 31.29 TWh with a carbon footprint of 17.29 MtCO2-eq, an estimate that is in the lower end of the range of results from previous studies. The main drivers of such impact were found to be the geographical distribution of miners and the efficiency of the mining equipment. In contrast to previous studies, it was found that the service life, production, and end-of-life of such equipment had only a minor contribution to the total impact, and that while the overall hashrate is expected to increase, the energy consumption and environmental footprint per TH mined is expected to decrease.


Assuntos
Pegada de Carbono , Tecnologia
6.
Lakartidningen ; 1162019 Oct 10.
Artigo em Sueco | MEDLINE | ID: mdl-31613372

RESUMO

This study estimated the climate footprint of halogenated inhalation anesthetics in Sweden and estimated effects of a decreased use of these compounds. We collected data on sales of desflurane, sevoflurane and isoflurane in Sweden during 2017 and calculated the mass of CO2 equivalents (CO2e) using Global Warming Potential data over 100 years for the compounds. Inhalation anesthetics contributed by 5000 tons of CO2e which corresponds to 0.005 percent of the Swedish climate footprint. By replacing desflurane with sevoflurane the footprint can be reduced by 73 percent. By replacing sevoflurane with intravenous propofol the climate effect can be reduced further by at least 2 orders of magnitude.


Assuntos
Anestésicos Inalatórios , Pegada de Carbono , Anestésicos Inalatórios/análise , Anestésicos Inalatórios/química , Anestésicos Intravenosos/análise , Anestésicos Intravenosos/química , Desflurano/análise , Desflurano/química , Aquecimento Global , Humanos , Isoflurano/análise , Isoflurano/química , Óxido Nitroso/análise , Óxido Nitroso/química , Propofol/administração & dosagem , Propofol/análise , Propofol/química , Sevoflurano/análise , Sevoflurano/química , Suécia
10.
Environ Sci Pollut Res Int ; 26(29): 30313-30323, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31432372

RESUMO

The Paris agreement (2015) seems a significant achievement towards a global mitigation policy to climate change. However, implementing the promised Intended Nationally Determined Contribution (INDC) targets by the participating countries has become a real challenge. In this aspect, the input-output life cycle assessment (IO-LCA) model provides an important assessment mechanism to design suitable abatement policies limiting the rising greenhouse gas (GHG) emissions. The present paper develops an IO-LCA model for Pakistan and estimates all the direct and indirect GHG emissions caused by all the production activities during all the stages of production. This task is achieved in three phases. In phase 1, the Pakistan input-output table (IOT) is constructed. In phase 2, the GHG environmental satellite accounts are created for each sector in the economy. In phase 3, the GHG emissions are linked to different categories of final demand.


Assuntos
Pegada de Carbono/economia , Desenvolvimento Econômico/tendências , Política Ambiental/economia , Efeito Estufa , Modelos Teóricos , Mudança Climática , Congressos como Assunto , Efeito Estufa/economia , Efeito Estufa/prevenção & controle , Paquistão , Formulação de Políticas
12.
J Environ Manage ; 248: 109243, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325793

RESUMO

Cities play an important role in controlling climate change. Previous 'city-scale studies' have investigated consumption-based emission accounting for demand-side mitigation analysis. However, to date very few studies have presented income-based emissions accounting for supply-side mitigation strategies at the level of an urban agglomeration. To fill this gap, this research begins by accounting for the income-based carbon footprint of the Beijing-Tianjin-Hebei (BTH) urban agglomeration. The 14 cities that make up the BTH region were grouped into 4 types in order to analyse the emission patterns of each and to identify both labour-intensive and carbon-efficient sectors. The results from this analysis are presented in a number of heatmaps, which show emission patterns, labour-capital ratios and carbon efficiencies. The industry relocation among the 14 cities is then discussed with regards to the Beijing-Tianjin-Hebei Coordinated Development Strategy. The results indicate that the service sector of Beijing, several mining sectors of resource-oriented cities and the electricity production for all of the cities are the most carbon-intensive sectors from an income-based perspective; the labour-intensive sectors are typically carbon-efficient, and the combination of supply-side carbon emissions, carbon efficiency and labour-to-capital ratio helps identify the key sectors for providing policy-makers the direction of industrial adjustment and relocation.


Assuntos
Pegada de Carbono , Carbono , Pequim , China , Cidades
13.
Water Sci Technol ; 79(11): 2211-2220, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31318359

RESUMO

Nowadays, low greenhouse gas (GHG) emission is expected at wastewater treatment plants (WWTPs). However, emission quantification and evaluation still faces difficulties related to data availability and uncertainty. The objective of this study was to perform carbon footprint (CF) analysis for two municipal WWTPs located in northern Poland. Slupsk WWTP is a large biological nutrient removal (BNR) facility (250,000 PE) which benefits from on-site electricity production from biogas. The other studied plant is a medium-size BNR facility in Starogard (60,000 PE). In this WWTP, all the required electricity was provided from the grid. Both wastewater systems were composed of activated sludge, with differences in the nutrient removal efficiency and sludge treatment line. The CF calculations were based on empirical models considering various categories of input parameters, afterwards summing up the emissions expressed in CO2 equivalents (CO2e). After sensitivity analysis, significant contributors to GHG emissions were identified. The total specific CF of the Slupsk and the Starogard WWTP was 17.3 and 38.8 CO2e per population equivalent (PE), respectively. In both cases, sludge management, electricity consumption and direct emissions from wastewater treatment were found to significantly influence the CF. A substantial share of the total CF originated from indirect emissions, primarily caused by the energy consumption. This negative impact can be partially overcome by increasing the share of renewable energy sources. Reduction of over 30% in the total CF could be achieved while applying energy recovery from biogas by combined heat and power plants. Farmland and farmland after composting were found to be the most appropriate strategies for sludge management. They could create a CF credit (8% of the total CF) as a result of substituting a synthetic fertilizer. Reliable full-scale measurements of N2O emissions from wastewater treatment are recommended due to high uncertainty in CF estimation based on fixed emission factors (EFs). While applying the lowest and the highest N2O EFs reported in the literature, the total CF would change even by 2-3 times.


Assuntos
Pegada de Carbono , Eliminação de Resíduos Líquidos , Águas Residuárias , Efeito Estufa , Polônia , Esgotos
14.
Lakartidningen ; 1162019 Feb 26.
Artigo em Sueco | MEDLINE | ID: mdl-31192417

RESUMO

This article provides insight from the Sustainable Development Unit, a top down policy, monitoring and delivery unit to support a large complex health system, the National Health Service, to embed sustainable development. The dedicated unit nurtured and supported bottom up action through top down change, it translated legal requirements, embedded good governance and engaged with stakeholders.By identifying a specific and manageable topic area the unit created an entry point to broader change and enabled action, in this case the unit started with carbon footprinting and reduction. Engagement of stakeholders was a mandate for strong governance and provided feedback of successes and future challenges. Progress was monitored through carbon reduction (18.5% over ten years), with over £1.8bn energy related savings, board approved Sustainable Development Measurement Plans (71% of trusts), and public annual sustainability reporting (85% of Clinical Commissioning Groups and trusts).


Assuntos
Assistência à Saúde , Desenvolvimento Sustentável , Dióxido de Carbono/análise , Pegada de Carbono , Gestão de Mudança , Inglaterra , Gases de Efeito Estufa/análise , Humanos
15.
Lakartidningen ; 1162019 Feb 26.
Artigo em Sueco | MEDLINE | ID: mdl-31192418

RESUMO

The Västra Götaland region carried out a project to develop resource-efficient surgeries using standardized hip prosthesis surgery as case. The purpose was to reduce and streamline the use of consumables and thus reduce the climate impact. At the surgery departments of three hospitals, significant variations were found in the supply and use of consumables during operations for total hip replacement (5.0-6.6 kg dry weight/operation). The major part of disposables consisted of surgery textiles, and choosing fossil-free products has the beneficial impact on a carbon footprint. Customized surgical procedure trays significantly reduce the number of packages and result in reduced work load for the staff. However, since there is a long term trend to increase the use of consumables in such sets, there is a need of continuous monitoring of such choices. In summary, a critical review of routines for care and use of materials is a powerful tool for streamlining healthcare and reducing its climate impact.


Assuntos
Artroplastia de Quadril , Pegada de Carbono , Equipamentos Descartáveis/estatística & dados numéricos , Equipamentos Cirúrgicos/estatística & dados numéricos , Artroplastia de Quadril/normas , Artroplastia de Quadril/estatística & dados numéricos , Humanos , Desenvolvimento Sustentável , Suécia
16.
Lakartidningen ; 1162019 Feb 26.
Artigo em Sueco | MEDLINE | ID: mdl-31192419

RESUMO

Health care is associated with a considerable climate impact and this short review describes approaches to reduce this impact. Reviews from WHO and World Bank Group end up with recommendations on low-carbon and resilient health care which is beneficial for health, economy and climate. The concept of climate-smart healthcare has been suggested as new way of describing this much needed work. In Skåne Region, Sweden a four-step method has been developed to reduce the climate impact of hospital care: to map and identify areas of greatest impact, to work with measures to reduce impact and evaluate the results. A test of this method showed a significant reduction in emission of CO2. In another project, fast-track access for patients with hematuria for diagnosis of bladder cancer showed that the median time from referral to diagnosis was reduced in comparison with conventional care with less costs and less use of resources associated with climate impact.


Assuntos
Pegada de Carbono , Assistência à Saúde , Dióxido de Carbono/análise , Gases de Efeito Estufa/análise , Humanos , Centro Cirúrgico Hospitalar/organização & administração , Desenvolvimento Sustentável , Suécia , Unidade Hospitalar de Urologia/organização & administração
17.
Lakartidningen ; 1162019 Feb 26.
Artigo em Sueco | MEDLINE | ID: mdl-31192420

RESUMO

The Swedish healthcare's share of public sector greenhouse gas emissions is approximately 20 per cent and this climate impact is mainly due to indirect emissions of purchased goods and services. In Region Västra Götaland, consumables used in healthcare are one of the largest single sources responsible for greenhouse gas emissions, similar to findings in other regions and countries. The focus on reducing the carbon footprint of healthcare is on measures to reduce disposables, to reduce need of transport and to save energy for heating, light, use of computers and medical devices.


Assuntos
Pegada de Carbono , Assistência à Saúde , Gases de Efeito Estufa/análise , Equipamentos Descartáveis , Fontes Geradoras de Energia , Alimentos , Humanos , Óxido Nitroso/análise , Desenvolvimento Sustentável , Suécia
18.
Water Res ; 162: 53-63, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31254886

RESUMO

Nitrous oxide (N2O) emitted from biological nutrient removal activated sludge systems contributes significantly to the total carbon footprint of modern wastewater treatment plants. In the present study, N2O production and emissions were experimentally determined in a large-scale plant (220,000 PE) employing combined nitrogen (N) and phosphorus (P) removal. As a modelling tool, the Activated Sludge Model 2d (ASM2d) was extended with modules describing multiple N2O production pathways and N2O liquid-gas transfers. The new model was calibrated and validated using the results of laboratory experiments and full-scale measurements. Different operational strategies were evaluated following the proposed model-based procedure. Heterotrophic denitrification was found to be the predominant pathway of N2O production under both anoxic and aerobic conditions. This behaviour could primarily be attributed to the predominant abundance of heterotrophic denitrifiers over nitrifiers. Simulations revealed that the optimal solution for minimizing liquid N2O production is to set the dissolved oxygen concentration in the aerobic zone from 1 to 2 mg O2/L and to enhance the mixed liquor recirculation rate (MLR) (>500% of the influent flowrate) while not compromising effluent standards. Regarding the actual conditions, the potential reduction in the carbon footprint was estimated to be 10% by applying the proposed operational strategy. The results suggest that considerable improvements can be achieved without substantial upgrades and increased costs.


Assuntos
Óxido Nitroso , Esgotos , Reatores Biológicos , Pegada de Carbono , Desnitrificação , Nitrogênio , Fósforo , Eliminação de Resíduos Líquidos
19.
Environ Sci Pollut Res Int ; 26(24): 25026-25036, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31250390

RESUMO

The aspiration of study is to explore the financial development-carbon footprint nexus in One Belt and Road initiative (BRI) region utilizing the panel dataset from 1990-2017. The cross-sectional dependence tests and second-generation panel unit tests were applied to affirm the cross-section dependence and integration level. The panel regression estimators from the Driscoll-Kraay standard error method for robust estimators in the presence of cross-sectional dependence have been applied to compute the estimators concerning the financial development-carbon footprint nexus for One Belt and Road economies. The estimates infer that financial development, urban population, and FDI have an adverse effect on carbon footprint. Furthermore, economic growth and energy consumption pollute the environment by enhancing the carbon footprint. Based on findings, it infers that financial development is a potential instrument to keep the environment through financial reforms. The estimates signify that it is necessary to allocate resources for renewable energy, energy efficiency, and energy conservation projects in order to moderate environmental degradation.


Assuntos
Pegada de Carbono , Energia Renovável/economia , Cimentos de Resina/química , Dióxido de Carbono/análise , Estudos Transversais , Desenvolvimento Econômico , Poluição Ambiental
20.
Water Res ; 161: 392-412, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31226538

RESUMO

Direct nitrous oxide (N2O) emissions during the biological nitrogen removal (BNR) processes can significantly increase the carbon footprint of wastewater treatment plant (WWTP) operations. Recent onsite measurement of N2O emissions at WWTPs have been used as an alternative to the controversial theoretical methods for the N2O calculation. The full-scale N2O monitoring campaigns help to expand our knowledge on the N2O production pathways and the triggering operational conditions of processes. The accurate N2O monitoring could help to find better process control solutions to mitigate N2O emissions of wastewater treatment systems. However, quantifying the emissions and understanding the long-term behaviour of N2O fluxes in WWTPs remains challenging and costly. A review of the recent full-scale N2O monitoring campaigns is conducted. The analysis covers the quantification and mitigation of emissions for different process groups, focusing on techniques that have been applied for the identification of dominant N2O pathways and triggering operational conditions, techniques using operational data and N2O data to identify mitigation measures and mechanistic modelling. The analysis of various studies showed that there are still difficulties in the comparison of N2O emissions and the development of emission factor (EF) databases; the N2O fluxes reported in literature vary significantly even among groups of similar processes. The results indicated that the duration of the monitoring campaigns can impact the EF range. Most N2O monitoring campaigns lasting less than one month, have reported N2O EFs less than 0.3% of the N-load, whereas studies lasting over a year have a median EF equal to 1.7% of the N-load. The findings of the current study indicate that complex feature extraction and multivariate data mining methods can efficiently convert wastewater operational and N2O data into information, determine complex relationships within the available datasets and boost the long-term understanding of the N2O fluxes behaviour. The acquisition of reliable full-scale N2O monitoring data is significant for the calibration and validation of the mechanistic models -describing the N2O emission generation in WWTPs. They can be combined with the multivariate tools to further enhance the interpretation of the complicated full-scale N2O emission patterns. Finally, a gap between the identification of effective N2O mitigation strategies and their actual implementation within the monitoring and control of WWTPs has been identified. This study concludes that there is a further need for i) long-term N2O monitoring studies, ii) development of data-driven methodological approaches for the analysis of WWTP operational and N2O data, and iii) better understanding of the trade-offs among N2O emissions, energy consumption and system performance to support the optimization of the WWTPs operation.


Assuntos
Óxido Nitroso , Águas Residuárias , Pegada de Carbono , Nitrogênio , Eliminação de Resíduos Líquidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA