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1.
J Environ Manage ; 318: 115567, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35759966

RESUMO

In this paper we conducted a life cycle assessment to evaluate the environmental performance of the valorization of spent pickling acid (SPA) generated in the hot-dip galvanizing (HDG) process. We analyzed the environmental impacts of treating one m3 of SPA, comparing the reference treatment consisting of neutralization, precipitation, stabilization, and landfilling of the metallic sludge (scenario #1), with the innovative LIFE2ACID technology (scenario #2) that produces secondary zinc and iron chloride in solution through non-dispersive solvent extraction (NDSX) and electrowinning (EW). The results showed that the materials credits achieved by the implementation of LIFE2ACID technology turned most of the impact categories evaluated (toxicity, acidification, eutrophication, ozone depletion, etc.) into environmental benefits. Scenario #2 was adapted to achieve either zinc-only recovery (#2.1) or simultaneous iron and zinc recovery (#2.2). The abiotic depletion potential (ADP) of fossil fuels increased slightly from scenario #1 to scenario #2.1 because of the higher energy demand and NaOH consumption of EW, and because only zinc was recovered. However, the valorization of both zinc and iron chloride in scenario #2.2 reduced the ADP-fossil by 27%, compared to the reference treatment. Furthermore, the global warming impact was reduced by 20% and 97% in scenarios #2.1 and #2.2, respectively. With the focus on promoting the circular economy concept, we conclude that the LIFE2ACID technology significantly improves the environmental performance of SPA management. Next steps should consider the life-cycle costs analysis in specific scenarios to find out the trade-off between environmental and economic objectives.


Assuntos
Cloretos , Zinco , Animais , Ácidos , Ferro , Estágios do Ciclo de Vida , Solventes
2.
Molecules ; 25(19)2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32998373

RESUMO

Climate change has become one of the most important challenges in the 21st century, and the electroreduction of CO2 to value-added products has gained increasing importance in recent years. In this context, formic acid or formate are interesting products because they could be used as raw materials in several industries as well as promising fuels in fuel cells. Despite the great number of studies published in the field of the electrocatalytic reduction of CO2 to formic acid/formate working with electrocatalysts of different nature and electrode configurations, few of them are focused on the comparison of different electrocatalyst materials and electrode configurations. Therefore, this work aims at presenting a rigorous and comprehensive comparative assessment of different experimental data previously published after many years of research in different working electrode configurations and electrocatalysts in a continuous mode with a single pass of the inputs through the reactor. Thus, the behavior of the CO2 electroreduction to formate is compared operating with Sn and Bi-based materials under Gas Diffusion Electrodes (GDEs) and Catalyst Coated Membrane Electrodes (CCMEs) configurations. Considering the same electrocatalyst, the use of CCMEs improves the performance in terms of formate concentration and energy consumption. Nevertheless, higher formate rates can be achieved with GDEs because they allow operation at higher current densities of up to 300 mA·cm-2. Bi-based-GDEs outperformed Sn-GDEs in all the figures of merit considered. The comparison also highlights that in CCME configuration, the employ of Bi-based-electrodes enhanced the behavior of the process, increasing the formate concentration by 35% and the Faradaic efficiency by 11%.


Assuntos
Bismuto/química , Dióxido de Carbono/química , Técnicas Eletroquímicas/métodos , Formiatos/química , Estanho/química , Catálise , Eletrodos , Oxirredução
3.
Environ Sci Technol ; 53(11): 6123-6132, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31075195

RESUMO

Waste managers struggle to comply with the European legislation that regulates the handling of organic waste. A waste management system that aims at recovering nutrients from the municipal organic waste generated in the Spanish region of Cantabria was modeled by combining material flow analysis, life cycle assessment, and life cycle costing. The model was optimized to find system configurations that minimize the total annual cost (TAC) and the global warming impacts (GW) and maximize the circularity indicators of nitrogen and phosphorus (CIN and CIP). The developed superstructure is composed of waste management unit processes and unit processes related to the land application of the recovered products (compost, digestate, (NH4)2SO4, and NH4MgPO4·6H2O) and industrial fertilizers to grow corn. The results of the optimization indicate that increasing CIN and minimizing GW raises the TAC, because of the investment in new technologies, although high CIP values can be achieved at low TACs. The economic margin that enables the organic fertilizers to compete in the market with industrial fertilizers was estimated. Cooperation between waste managers, the farmers that purchase the recovered products, and the policy-makers that set the waste management taxes can minimize the costs that hinder the transition toward a circular economy.


Assuntos
Nutrientes , Gerenciamento de Resíduos , Fertilizantes , Nitrogênio , Fósforo
4.
Environ Sci Technol ; 52(19): 10923-10933, 2018 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-30170493

RESUMO

Measuring the circularity of resources is essential to assessing the performance of a circular economy. This work aims at proposing an indicator that quantifies how effective a system is at extending the lifetime of its waste components after they have been discarded. The developed indicator was applied to study the circularity of nutrients within a system that handles the organic waste (OW) generated in the Spanish region of Cantabria. A superstructure was developed to determine the optimal configuration of the system. It is composed of alternative unit processes for (1) the management of OW and (2) the application of the recovered products as soil amendment to grow corn. A multiobjective mixed integer linear programming problem was formulated under two policy scenarios with different source separation rates. The problem was optimized according to six objective functions: the circularity indicators of carbon, nitrogen, and phosphorus, which are maximized, and their associated environmental impacts to be minimized (global warming, marine eutrophication, and freshwater eutrophication). The model was fed with the life cycle assessment results obtained with the Environmental Assessment System for Environmental TECHnologies (EASETECH) version 2.3.6 and the nutrient flows in the agriculture subsystem, which were calculated with Denitrification-Decomposition (DNDC) version 9.5. It was concluded that improving nutrient circularity paradoxically leads to eutrophication impacts and that increasing the SSR of OW has a positive effect on the carbon footprint of the system.


Assuntos
Nutrientes , Gerenciamento de Resíduos , Agricultura , Eutrofização , Nitrogênio , Fósforo
5.
JACS Au ; 3(10): 2631-2639, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37885586

RESUMO

The development of emerging decarbonization technologies requires advanced tools for decision-making that incorporate the environmental perspective from the early design. Today, Life Cycle Assessment (LCA) is the preferred tool to promote sustainability in the technology development, identifying environmental challenges and opportunities and defining the final implementation pathways. So far, most environmental studies related to decarbonization emerging solutions are still limited to midpoint metrics, mainly the carbon footprint, with global sustainability implications being relatively unexplored. In this sense, the Planetary Boundaries (PBs) have been recently proposed to identify the distance to the ideal reference state. Hence, PB-LCA methodology can be currently applied to transform the resource use and emissions to changes in the values of PB control variables. This study shows a complete picture of the LCA's role in developing emerging technologies. For this purpose, a case study based on the electrochemical conversion of CO2 to formic acid is used to show the possibilities of LCA approaches highlighting the potential pitfalls when going beyond greenhouse gas emission reduction and obtaining the absolute sustainability level in terms of four PBs.

6.
Membranes (Basel) ; 13(2)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36837633

RESUMO

Carbon dioxide (CO2) is the single largest contributor to climate change due to its increased emissions since global industrialization began. Carbon Capture, Storage, and Utilization (CCSU) is regarded as a promising strategy to mitigate climate change, reducing the atmospheric concentration of CO2 from power and industrial activities. Post-combustion carbon capture (PCC) is necessary to implement CCSU into existing facilities without changing the combustion block. In this study, the recent research on various PCC technologies is discussed, along with the membrane technology for PCC, emphasizing the different types of membranes and their gas separation performances. Additionally, an overall comparison of membrane separation technology with respect to other PCC methods is implemented based on six different key parameters-CO2 purity and recovery, technological maturity, scalability, environmental concerns, and capital and operational expenditures. In general, membrane separation is found to be the most competitive technique in conventional absorption as long as the highly-performed membrane materials and the technology itself reach the full commercialization stage. Recent updates on the main characteristics of different flue gas streams and the Technology Readiness Levels (TRL) of each PCC technology are also provided with a brief discussion of their latest progresses.

7.
Environ Monit Assess ; 184(11): 6513-26, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22210123

RESUMO

The aim of the present study was to evaluate the polycyclic aromatic hydrocarbon (PAH) and polychlorinated biphenyl (PCB) levels in PM(10) and PM(2.5), at one rural and three urban sites in the Cantabria region (northern Spain). From all of these pollutants, benzo(a)pyrene is regulated by the EU air quality directives; its target value (1 ng/m(3)) was not exceeded. The concentration values of the studied organic pollutants at the studied sites are in the range of those obtained at other European sites. A comparison between the rural-urban stations was developed: (a) PAH concentration values were lower in the rural site (except for fluorene). Therefore, the contribution of local sources to the urban levels of PAHs seems relevant. Results from the coefficient of divergence show that the urban PAH levels are influenced by different local emission sources. (b) PCB rural concentration values were higher than those found at urban sites. Because no local sources of PCBs were identified in the rural site, the contribution of more distant emission sources (about 40 km) to the PCB levels is considered to be the most important; the long-range transport of PCBs does not seem to be significant. Additionally, local PAH tracers were identified by a triangular diagram: higher molecular weight PAHs in Reinosa, naphthalene in Santander and anthracene/pyrene in Castro Urdiales. A preliminary PAH source apportionment study in the urban sites was conducted by means of diagnostic ratios. The ratios are similar to those reported in areas affected by traffic emissions; they also suggest an industrial emission source at Reinosa.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluição do Ar/estatística & dados numéricos , Tamanho da Partícula , Espanha
8.
Membranes (Basel) ; 12(8)2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36005698

RESUMO

This work explores the potential of novel renewable materials in electrode fabrication for the electrochemical conversion of carbon dioxide (CO2) to ethylene in alkaline media. In this regard, the use of the renewable chitosan (CS) biopolymer as ion-exchange binder of the copper (Cu) electrocatalyst nanoparticles (NPs) is compared with commercial anion-exchange binders Sustainion and Fumion on the fabrication of gas diffusion electrodes (GDEs) for the electrochemical reduction of carbon dioxide (CO2R) in an alkaline medium. They were tested in membrane electrode assemblies (MEAs), where selectivity to ethylene (C2H4) increased when using the Cu:CS GDE compared to the Cu:Sustainion and Cu:Fumion GDEs, respectively, with a Faradaic efficiency (FE) of 93.7% at 10 mA cm-2 and a cell potential of -1.9 V, with a C2H4 production rate of 420 µmol m-2 s-1 for the Cu:CS GDE. Upon increasing current density to 90 mA cm-2, however, the production rate of the Cu:CS GDE rose to 509 µmol/m2s but the FE dropped to 69% due to increasing hydrogen evolution reaction (HER) competition. The control of mass transport limitations by tuning up the membrane overlayer properties in membrane coated electrodes (MCE) prepared by coating a CS-based membrane over the Cu:CS GDE enhanced its selectivity to C2H4 to a FE of 98% at 10 mA cm-2 with negligible competing HER. The concentration of carbon monoxide was below the experimental detection limit irrespective of the current density, with no CO2 crossover to the anodic compartment. This study suggests there may be potential in sustainable alernatives to fossil-based or perfluorinated materials in ion-exchange membrane and electrode fabrication, which constitute a step forward towards decarbonization in the circular economy perspective.

9.
Membranes (Basel) ; 12(8)2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36005700

RESUMO

Carbon Capture Utilization and Storage technologies are essential mitigation options to reach net-zero CO2 emissions. However, this challenge requires the development of sustainable and economic separation technologies. This work presents a novel CO2 capture technology strategy based on non-dispersive CO2 absorption and membrane vacuum regeneration (MVR) technology, and employs two imidazolium ionic liquids (ILs), [emim][Ac] and [emim][MS], with different behavior to absorb CO2. Continuous absorption-desorption experiments were carried out using polypropylene hollow fiber membrane contactors. The results show the highest desorption behavior in the case of [emim][Ac], with a MVR performance efficiency of 92% at 313 K and vacuum pressure of 0.04 bar. On the other hand, the IL [emim][MS] reached an efficiency of 83% under the same conditions. The MVR technology could increase the overall CO2 capture performance by up to 61% for [emim][Ac] and 21% for [emim][MS], which represents an increase of 26% and 9%, respectively. Moreover, adding 30%vol. demonstrates that the process was only favorable by using the physical IL. The results presented here indicate the interest in membrane vacuum regeneration technology based on chemical ILs, but further techno-economic evaluation is needed to ensure the competitiveness of this novel CO2 desorption approach for large-scale application.

10.
Sci Total Environ ; 820: 153189, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35051482

RESUMO

Shipping is a very important source of pollution worldwide. In recent years, numerous actions and measures have been developed trying to reduce the levels of greenhouse gases (GHG) from the marine exhaust emissions in the fight against climate change, boosting the Sustainable Development Goal 13. Following this target, the action of hydrogen as energy vector makes it a suitable alternative to be used as fuel, constituting a very promising energy carrier for energy transition and decarbonization in maritime transport. The objective of this study is to develop an ex-ante environmental evaluation of two promising technologies for vessels propulsion, a H2 Polymeric Electrolytic Membrane Fuel Cell (PEMFC), and a H2 Internal Combustion Engine (ICE), in order to determine their viability and eligibility compared to the traditional one, a diesel ICE. The applied methodology follows the Life Cycle Assessment (LCA) guidelines, considering a functional unit of 1 kWh of energy produced. LCA results reveal that both alternatives have great potential to promote the energy transition, particularly the H2 ICE. However, as technologies readiness level is quite low, it was concluded that the assessment has been conducted at a very early stage, so their sustainability and environmental performance may change as they become more widely developed and deployed, which can be only achieved with political and stakeholder's involvement and collaboration.


Assuntos
Gases de Efeito Estufa , Hidrogênio , Animais , Efeito Estufa , Estágios do Ciclo de Vida , Navios , Emissões de Veículos/análise
11.
Sci Rep ; 12(1): 8505, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35595765

RESUMO

The doping of zirconium based EHU-30 and EHU-30-NH2 metal-organic frameworks with copper(II) yielded a homogeneous distribution of the dopant with a copper/zirconium ratio of 0.04-0.05. The doping mechanism is analysed by chemical analysis, microstructural analysis and pair distribution function (PDF) analysis of synchrotron total scattering data in order to get deeper insight into the local structure. According to these data, the Cu(II) atoms are assembled within the secondary building unit by a transmetalation reaction, contrarily to UiO-66 series in which the post-synthetic metalation of the MOF takes place through chemical anchorage. The resulting materials doubled the overall performance of the parent compounds for the CO2 electroreduction, while retained stable the performance during continuous transformation reaction.

12.
Environ Monit Assess ; 176(1-4): 385-401, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-20617459

RESUMO

This paper documents levels of organochlorine pesticides (OCs) in coastal surface sediments from selected reference sites on the northern Atlantic Spanish coast. One hundred eight samples covering three estuaries in the Cantabrian Coast were sampled in 2006 and analyzed in the finer fraction (<63 µm) for 19 OCs by gas chromatography with electron capture detector after confirmation by mass spectrometry. Detected organochlorine pesticides were endosulfan α, endosulfan ß, endosulfan sulfate, hexachlorobenzene (HCB), aldrin, dieldrin, methoxychlor, 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4'-DDE) and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (4,4'-DDD). Total OCs concentrations ranged from 1.8 ng g(-1) dry weight (dw) to 3.9 ng g(-1) dw, showing a uniform distribution along the studied area, and being consistent with recorded levels in the literature for coastal sediments in other reference sites with low levels of pollution by OCs along the Atlantic Ocean. Endosulfan, 4,4'-DDD, HCB, aldrin, and dieldrin seemed to be ubiquitous as the legacy of past uses and deposition. OCs concentrations were significantly correlated to organic matter content and particle size distribution. No adverse biological effects derived from these pollutants are expected to take place as it can be concluded from the comparison with the existent marine sediment quality guidelines.


Assuntos
Sedimentos Geológicos/análise , Hidrocarbonetos Clorados/análise , Resíduos de Praguicidas/análise , Poluentes Químicos da Água/análise , Oceano Atlântico , Monitoramento Ambiental , Espanha
13.
Waste Manag ; 124: 244-253, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33636426

RESUMO

Unclosed coastal landfills in small island developing states are major sources of greenhouse gases and other environmental impacts. This is a major problem for sustainable waste management systems mainly due to the lack of economic resources. The clean development mechanism (CDM) appears as a possibility to facilitate sustainable financing. Implementing a methane oxidation layer (MOL) emerges as a feasible technical option for this kind of small landfills since landfill gas extraction is usually not viable. This paper presents a techno-economic and environmental assessment of MOL implementation in the Providence landfill (Seychelles) as a small-scale CDM measure. Results show that the MOL measure could avoid by 2030 between 94 and 20 kt CO2 eq. Concerning profitability, results clearly show that it depends on the existence of stabilized biomass material within the island. Thus, the MOL measure starts to be profitable in some scenarios for certified emission reductions (CER) prices higher than 26 €/t CO2 eq. that seem possible depending on the emissions' market development. When not profitable under CDM, the MOL measure might be used to reduce CO2 emissions from the domestic climate effort under the Paris Agreement since the unitary abatement costs is between 10 and 423 €/t CO2 eq. Moreover, the MOL measure contributes to the sustainable development goals (SDG) achievement - mainly SDG8, SDG13, and SDG14. Finally, results call for a prompt action in Seychelles since the sooner the MOL is implemented after the landfill is closed, the more profitable.


Assuntos
Poluentes Atmosféricos , Eliminação de Resíduos , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Metano/análise , Paris , Seicheles , Instalações de Eliminação de Resíduos
14.
J Environ Monit ; 12(7): 1451-8, 2010 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-20517581

RESUMO

The aim of this study was to evaluate the contribution of local emission sources to the selected trace metals levels (As, Ni, Cd, Pb, Ti, V, Mn, Cu, Mo and Hg) in urban particulate matter, PM10 and PM2.5, in the Cantabria region (Northern Spain) during the year 2008. PM10 and PM2.5 samples were collected and characterized in an urban sampling site at Santander (Cantabria); additional PM10 samples were collected at a rural site at Los Tojos (50 Km SW) to evaluate both the urban and rural environment. The particulate matter and the metals regulated by the EC air quality directives (Pb, As, Ni and Cd) did not exceed the EC limit or target values in the Cantabria region. The metal concentrations were much lower at the rural site except for Ni. Different techniques were used to analyse the possible sources of the studied metals: enrichment factor, urban impact, wind and pollutant roses and principal component analysis (PCA). A combination of these techniques allowed us to demonstrate that the local emission sources of metals in the particulate matter at Santander city were the most important. Ti, Ni, As and V were identified as the main urban background tracers while Mn and Pb were the main local industrial tracers. The urban background was found to be the major contributor to PM10. The relationship between the emission tracers and the major air pollutants (NO(2), NO, CO, SO(2),O(3) and PM(10)) was also studied by PCA; a significant relationship between tracers and the major air pollutants was not found, showing a decoupled relationship between major pollutants and metal species in particulate matter.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Metais/análise , Material Particulado/análise , Poluição do Ar/estatística & dados numéricos , Atmosfera/química , Cidades , Tamanho da Partícula , Espanha
15.
Membranes (Basel) ; 10(12)2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33302433

RESUMO

Membrane technology is a simple and energy-conservative separation option that is considered to be a green alternative for CO2 capture processes. However, commercially available membranes still face challenges regarding water and chemical resistance. In this study, the effect of water and organic contaminants in the feed stream on the CO2/CH4 separation performance is evaluated as a function of the hydrophilic and permselective features of the top layer of the membrane. The membranes were a commercial hydrophobic membrane with a polydimethylsiloxane (PDMS) top layer (Sulzer Chemtech) and a hydrophilic flat composite membrane with a hydrophilic [emim][ac] ionic liquid-chitosan (IL-CS) thin layer on a commercial polyethersulfone (PES) support developed in our laboratory. Both membranes were immersed in NaOH 1M solutions and washed thoroughly before characterization. The CO2 permeance was similar for both NaOH-treated membranes in the whole range of feed concentration (up to 250 GPU). The presence of water vapor and organic impurities of the feed gas largely affects the gas permeance through the hydrophobic PDMS membrane, while the behavior of the hydrophilic IL-CS/PES membranes is scarcely affected. The effects of the interaction of the contaminants in the membrane selective layer are being further evaluated.

16.
Membranes (Basel) ; 10(2)2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32075000

RESUMO

Lignin is one of the three main components of lignocellulosic biomass and must be considered a raw material with attractive applications from an economic and ecological point of view. Therefore, biorefineries must have in mind the most adequate processing to obtain high-quality lignin and the separation tasks that play a key role to improve the purity of the lignin. Separation techniques based on membranes are a promising way to achieve these requirements. In this work, the separation performance of the SILM (Supported Ionic Liquid Membrane) formed with [BMIM][DBP] as IL (Ionic Liquid) and PTFE as membrane support was compared to a nanofiltration (NF) membrane (NP010 by Microdyn-Nadir) and two ultrafiltration (UF) membranes (UF5 and UF10 by Trisep). The SILM showed selective transport of Kraft lignin, lignosulphonate, xylose, and glucose in aqueous solutions. Although it was stable under different conditions and its performance was improved by the integration of agitation, it was not competitive when compared to NF and UF membranes, although the latter ones suffered fouling. The NF membrane was the best alternative for the separation of lignosulphonates from monosaccharides (separation factors around 75 while SILM attained only values lower than 3), while the UF5 membrane should be selected to separate Kraft lignin and monosaccharides (separation factors around 100 while SILM attained only values below 3).

17.
Membranes (Basel) ; 10(9)2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32937879

RESUMO

In this work, the membrane vacuum regeneration (MVR) process was considered as a promising technology for solvent regeneration in post-combustion CO2 capture and utilization (CCU) since high purity CO2 is needed for a technical valorization approach. First, a desorption test by MVR using polypropylene hollow fiber membrane contactor (PP-HFMC) was carried out in order to evaluate the behavior of physical and physico-chemical absorbents in terms of CO2 solubility and regeneration efficiency. The ionic liquid 1-ethyl-3-methylimidazolium acetate, [emim][Ac], was presented as a suitable alternative to conventional amine-based absorbents. Then, a rigorous two-dimensional mathematical model of the MVR process in a HFMC was developed based on a pseudo-steady-state to understand the influence of the solvent regeneration process in the absorption-desorption process. CO2 absorption-desorption experiments in PP-HFMC at different operating conditions for desorption, varying vacuum pressure and temperature, were used for model validation. Results showed that MVR efficiency increased from 3% at room temperature and 500 mbar to 95% at 310K and 40 mbar vacuum. Moreover, model deviation studies were carried out using sensitivity analysis of Henry's constant and pre-exponential factor of chemical interaction, thus as to contribute to the knowledge in further works.

18.
Environ Sci Pollut Res Int ; 27(2): 1256-1266, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30919196

RESUMO

The integration of electrodialysis with bipolar membranes (EDBM) with seawater reverse osmosis (SWRO) process influences the two main environmental burdens of SWRO desalination process: climate change, accounted here as carbon footprint (CF) and associated to the high-energy consumption, and the environmental alteration of the vicinities of the facility, due to brine disposal. EDBM powered by photovoltaic (PV) solar energy is able to meet the above-mentioned challenges that arise in SWRO desalination. In addition, HCl and NaOH, both employed in the desalination industry, can be produced from the brines. Hence, environmental benefits regarding the potential self-supply can be achieved. The environmental sustainability assessment by means of life cycle assessment (LCA) of a SWRO and EDBM has been carried out considering four different scenarios. The percentage of treated brines and the influence of the grid mix used for electric power supply has been taken into account. The three different electric power supplies were 100.0% renewable energy (PV solar energy), 36.0% renewable energy (average Spanish grid mix), and 1.9% (average Israeli grid mix). The results showed that the CF per unit of volume produced freshwater for SWRO and the self-supply reagent production scenario for the three Spanish grid mix, the Israeli grid mix, and the PV solar energy were 6.96 kg CO2-eq·m-3, 12.57 kg CO2-eq·m-3, and 2.17 kg CO2-eq·m-3, respectively.


Assuntos
Sais/análise , Purificação da Água , Osmose , Sais/química , Água do Mar
19.
Membranes (Basel) ; 10(1)2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31905891

RESUMO

In this work, the performance of new robust mixed matrix composite hollow fiber (MMCHF) membranes with a different selective layer composition is evaluated in the absence and presence of water vapor in CO2/N2 and CO2/CH4 separation. The selective layer of these membranes is made of highly permeable hydrophobic poly(trimethyl-1-silylpropine) (PTMSP) and hydrophilic chitosan-ionic liquid (IL-CS) hybrid matrices, respectively, filled with hydrophilic zeolite 4A particles in the first case and HKUST-1 nanoparticles in the second, coated over compatible supports. The effect of water vapor in the feed or using a commercial hydrophobic PDMSXA-10 HF membrane has also been studied for comparison. Mixed gas separation experiments were performed at values of 0 and 50% relative humidity (RH) in the feed and varying CO2 concentration in N2 and CH4, respectively. The performance has been validated by a simple mathematical model considering the effect of temperature and relative humidity on membrane permeability.

20.
Sci Total Environ ; 689: 1255-1275, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31466164

RESUMO

Waste remains a serious environmental and human health hazard in developing nations, including those in Latin America and the Caribbean (LA&C). Despite important breakthroughs in waste management in LA&C, the region still faces many challenges that require special attention, such as the existence of uncontrolled open dumpsters (33%) or the low recovery rates of waste fractions (below 4%). Moreover, the adoption of sophisticated waste management technologies, such as incineration or anaerobic digestion, is still lagging. This review paper provides environmentally-sound and relevant policy support for municipal solid waste management stakeholders through a critical review of the current situation of the waste management sector in LA&C from an environmental perspective. Thereafter, Life Cycle Assessment (LCA) bibliography linked to waste management, namely collection, sorting, recycling and landfilling applications and technologies worldwide, is used in order to understand potential alternative waste management strategies in LA&C, as well as the potential environmental benefits that could be attained. Finally, based on the holistic review and analysis, the adoption of more sophisticated technologies in landfill sites (e.g. landfill gas flaring), waste-to-energy, as well as higher recycling rates, would enhance waste management in the region and mitigate environmental impacts. A holistic view to support policy formulations, including climate action, for the adoption of integrated waste management strategies in LA&C is imperative.

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