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1.
J Environ Manage ; 364: 121442, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38870793

ABSTRACT

The widespread use of low or medium pressure mercury lamps in UV-C water disinfection should consider recent advances in UV-C LED lamps that offer a more sustainable approach and avoid its main drawbacks. The type of water and the mode of operation are critical when deciding on the treatment technology to be used. Therefore, this study investigates the potential application of UV-C LED disinfection technology in terms of kinetics, environmental assessment, and economic analysis for two scenarios: the continuous disinfection of a wastewater treatment plant (WWTP), and disinfection of harvested rainwater (RWH) in a residential household that operates intermittently. Experiments are conducted using both the new UV-C LED system and the conventional mercury lamp to disinfect real wastewater. Removal of total coliforms and Escherichia coli bacteria, with concentrations of approximately 105 and 104 CFU per 100 mL has been followed to assess the performance of both types of UV-C lamps. The experimental study provides kinetic parameters that have been further used in the environmental assessment conducted from a life cycle perspective. Additionally, considering the significant role of electricity consumption, a preliminary economic analysis has been conducted. The results indicate that first-order kinetic constants of pathogens removal with UV-C LEDs achieve 1.4 times higher values than Hg lamp. Regarding the environmental and economic assessment, for disinfection systems operating continuously, LEDs result in environmental impacts 5 times higher than Hg lamp in most categories, indicating that Hg lamps offer a viable option both from economic and environmental point of view. However, for installations with intermittent operation, LEDs emerge as the most competitive alternative, due to their ability to be turned on and off without affecting their lifespan. This study shows that UV-C LED lamps hold promise to replace conventional mercury lamps in a near future.

2.
Chemosphere ; 349: 140806, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38040252

ABSTRACT

This work studies the photocatalytic degradation of solutions containing 0.11 mM of a glucocorticoid (dexamethasone, DEX) and 0.11 mM of an herbicide (S-metolachlor, MTLC), organohalogenated compounds containing fluorine and chlorine atoms in their molecules, respectively. To treat 1 L volume, a mass of 0.5 g of TiO2/rGO composite in suspension has been used as photocatalyst, irradiated with UV-A LEDs with 200 W m-2 of irradiance. MTLC is partially adsorbed on the surface of the catalyst, while DEX is not adsorbed, showing different degradation kinetics. The halogen ions released into the solution from the breakage of the parent molecules, F- and Cl- respectively, were analysed. In the case of MTLC, the released Cl- followed two different kinetic trends, being faster, and with a rate that matched the rate of MTLC disappearance, the part corresponding to non-adsorbed MTLC. In the experiments with DEX solutions a different behaviour was observed; the released F- in the photocatalytic degradation was partially adsorbed on the catalyst surface, but the adsorption capacity decreased with the use of the photocatalyst in consecutive cycles until the solubilised F- matched the degraded concentration of DEX. Furthermore, the mass balance between the degraded contaminant and the solubilised halogen anion, for both contaminants, allowed to conclude the absence of halogenated intermediates under the final operating conditions, that is a remarkable outcome in water remediation processes.


Subject(s)
Environmental Pollutants , Photolysis , Halogens , Dexamethasone , Titanium , Catalysis
3.
Biosensors (Basel) ; 13(12)2023 Dec 15.
Article in English | MEDLINE | ID: mdl-38131792

ABSTRACT

Diabetes is expected to rise substantially by 2045, prompting extensive research into accessible glucose electrochemical sensors, especially those based on non-enzymatic materials. In this context, advancing the knowledge of stable metal-based compounds as alternatives to non-enzymatic sensors becomes a scientific challenge. Nonetheless, these materials have encountered difficulties in maintaining stable responses under physiological conditions. This work aims to advance knowledge related to the synthesis and characterization of copper-based electrodes for glucose detection. The microelectrode presented here exhibits a wide linear range and a sensitivity of 1009 µA∙cm-2∙mM-1, overperfoming the results reported in literature so far. This electrode material has also demonstrated outstanding results in terms of reproducibility, repeatability, and stability, thereby meeting ISO 15197:2015 standards. Our study guides future research on next-generation sensors that combine copper with other materials to enhance activity in neutral media.


Subject(s)
Biosensing Techniques , Glucose , Copper/chemistry , Reproducibility of Results , Biosensing Techniques/methods , Electrochemical Techniques , Electrodes , Microelectrodes
4.
JACS Au ; 3(10): 2631-2639, 2023 Oct 23.
Article in English | MEDLINE | ID: mdl-37885586

ABSTRACT

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.

5.
Int J Pharm ; 643: 123232, 2023 Aug 25.
Article in English | MEDLINE | ID: mdl-37460049

ABSTRACT

During the last decades, there has been growing interest in the application of functionalized mesoporous nanomaterials as stimuli-responsive carriers for drug delivery. However, at present there is not a standardized methodology to evaluate their performance. The limitations of the different techniques reported in literature give rise to the necessity for new, simple, and cost-effective alternatives. This work constitutes a step forward in the development of advanced in vitro procedures for testing the behavior of nanocarriers, proposing a novel microfluidic platform. To test the capacity of the reported tool, the performance of amino-functionalized MCM-41 nanoparticles has been assessed. These materials show a pH-responsive mechanism, which prevents the drug release at acidic conditions, maximizing its distribution at neutral pH, thus, the selected release medium mimicked gastrointestinal conditions. As a first approximation, the delivery of Ru(bipy)32+ was evaluated, proving the advantages of the proposed microfluidic system: i) continuous flow of particles and media, ii) rigorous control of the residence time, temperature and pH, iii) enhanced mixing, iv) possibility to simulate different human body conditions and, v) possible integration with the continuous synthesis of nanocarriers. Finally, the microfluidic tool was used to analyze the delivery of the anti-inflammatory drug ibuprofen.


Subject(s)
Drug Carriers , Nanoparticles , Humans , Microfluidics , Drug Delivery Systems , Silicon Dioxide , Hydrogen-Ion Concentration , Drug Liberation
6.
Membranes (Basel) ; 13(6)2023 May 24.
Article in English | MEDLINE | ID: mdl-37367750

ABSTRACT

The chemical potential difference at the discharge points of coastal Wastewater Treatment Plants (WWTPs) uncovers the opportunity to harness renewable salinity gradient energy (SGE). This work performs an upscaling assessment of reverse electrodialysis (RED) for SGE harvesting of two selected WWTPs located in Europe, quantified in terms of net present value (NPV). For that purpose, a design tool based on an optimization model formulated as a Generalized Disjunctive Program previously developed by the research group has been applied. The industrial scale-up of SGE-RED has already proven to be technically and economically feasible in the Ierapetra medium-sized plant (Greece), mainly due to a greater volumetric flow and a warmer temperature. At the current price of electricity in Greece and the up-to-date market cost of membranes of 10 EUR/m2, the NPV of an optimized RED plant in Ierapetra would amount to EUR117 thousand operating with 30 RUs in winter and EUR 157 thousand for 32 RUs in summer, harnessing 10.43 kW and 11.96 kW of SGE for the winter and summer seasons, respectively. However, in the Comillas facility (Spain), this could be cost-competitive with conventional alternatives, namely coal or nuclear power, under certain conditions such as lower capital expenses due to affordable membrane commercialization (4 EUR/m2). Bringing the membrane price down to 4 EUR/m2 would place the SGE-RED's Levelized Cost of Energy in the range of 83 EUR/MWh to 106 EUR/MWh, similar to renewable sources such as solar PV residential rooftops.

7.
J Chem Inf Model ; 63(8): 2495-2504, 2023 04 24.
Article in English | MEDLINE | ID: mdl-37026789

ABSTRACT

The globally expanding threat of antibiotic resistance calls for the development of new strategies for abating Gram-negative bacterial infections. The use of extracorporeal blood cleansing devices with affinity sorbents to selectively capture bacterial lipopolysaccharide (LPS), which is the major constituent of Gram-negative bacterial outer membranes and the responsible agent for eliciting an exacerbated innate immune response in the host during infection, has received outstanding interest. For that purpose, molecules that bind tightly to LPS are required to functionalize the affinity sorbents. Particularly, anti-LPS factors (ALFs) are promising LPS-sequestrating molecules. Hence, in this work, molecular dynamics (MD) simulations are used to investigate the interaction mechanism and binding pose of the ALF isoform 3 from Penaeus monodon (ALFPm3), which is referred to as "AL3" for the sake of simplicity, and lipid A (LA, the component of LPS that represents its endotoxic principle). We concluded that hydrophobic interactions are responsible for AL3-LA binding and that LA binds to AL3 within the protein cavity, where it buries its aliphatic tails, whereas the negatively charged phosphate groups are exposed to the medium. AL3 residues that are key for its interaction with LA were identified, and their conservation in other ALFs (specifically Lys39 and Tyr49) was also analyzed. Additionally, based on the MD-derived results, we provide a picture of the possible AL3-LA interaction mechanism. Finally, an in vitro validation of the in silico predictions was performed. Overall, the insights gained from this work can guide the design of novel therapeutics for treating sepsis, since they may be significantly valuable for designing LPS-sequestrating molecules that could functionalize affinity sorbents to be used for extracorporeal blood detoxification.


Subject(s)
Lipid A , Penaeidae , Animals , Lipopolysaccharides/pharmacology , Penaeidae/metabolism , Penaeidae/microbiology , Molecular Dynamics Simulation , Protein Isoforms/metabolism
8.
Membranes (Basel) ; 13(4)2023 Apr 20.
Article in English | MEDLINE | ID: mdl-37103875

ABSTRACT

This work presents the photocatalytic degradation of organic pollutants in water with TiO2 and TiO2/Ag membranes prepared by immobilising photocatalysts on ceramic porous tubular supports. The permeation capacity of TiO2 and TiO2/Ag membranes was checked before the photocatalytic application, showing high water fluxes (≈758 and 690 L m-2 h-1 bar-1, respectively) and <2% rejection against the model pollutants sodium dodecylbenzene sulfonate (DBS) and dichloroacetic acid (DCA). When the membranes were submerged in the aqueous solutions and irradiated with UV-A LEDs, the photocatalytic performance factors for the degradation of DCA were similar to those obtained with suspended TiO2 particles (1.1-fold and 1.2-fold increase, respectively). However, when the aqueous solution permeated through the pores of the photocatalytic membrane, the performance factors and kinetics were two-fold higher than for the submerged membranes, mostly due to the enhanced contact between the pollutants and the membranes photocatalytic sites where reactive species were generated. These results confirm the advantages of working in a flow-through mode with submerged photocatalytic membranes for the treatment of water polluted with persistent organic molecules, thanks to the reduction in the mass transfer limitations.

9.
Membranes (Basel) ; 13(3)2023 Mar 10.
Article in English | MEDLINE | ID: mdl-36984709

ABSTRACT

Salinity gradient energy has gained attention in recent years as a renewable energy source, especially employing reverse electrodialysis technology (RED), which is based on the role of ion exchange membranes. In this context, many efforts have been developed by researchers from all over the world to advance the knowledge of this green source of energy. However, the influence of divalent ions on the performance of the technology has not been deeply studied. Basically, divalent ions are responsible for an increased membrane resistance and, therefore, for a decrease in voltage. This work focuses on the estimation of the resistance of the RED membrane working with water flows containing divalent ions, both theoretically by combining the one-thread model with the Donnan exclusion theory for the gel phase, as well as the experimental evaluation with Fumatech membranes FAS-50, FKS-50, FAS-PET-75, and FKS-PET-75. Furthermore, simulated results have been compared to data recently reported with different membranes. Besides, the influence of membrane resistance on the overall performance of reverse electrodialysis technology is evaluated to understand the impact of divalent ions in energy generation. Results reflect a minor effect of sulfate on the gross power in comparison to the effect of calcium and magnesium ions. Thus, this work takes a step forward in the knowledge of reverse electrodialysis technology and the extraction of salinity gradient energy by advancing the influence of divalent ions on energy recovery.

10.
RSC Adv ; 13(10): 6481-6489, 2023 Feb 21.
Article in English | MEDLINE | ID: mdl-36845587

ABSTRACT

The management of spent pickling acids (SPA) is an environmental challenge for the hot-dip galvanizing (HDG) industry. Bearing in mind its elevated content of iron and zinc, SPA can be regarded as a source of secondary materials in a circular economy approach. This work reports the pilot scale demonstration of non-dispersive solvent extraction (NDSX) in hollow fiber membrane contactors (HFMCs) to perform the selective zinc separation and SPA purification, so that the characteristics needed for use as a source of iron chloride are achieved. The operation of the NDSX pilot plant, which incorporates four HFMCs with a 80 m2 nominal membrane area, is carried out with SPA supplied by an industrial galvanizer, and consequently technology readiness level (TRL) 7 is reached. The purification of the SPA requires of a novel feed and purge strategy to operate the pilot plant in continuous mode. To facilitate the further implementation of the process, the extraction system is formed by tributyl phosphate as the organic extractant and tap water as the stripping agent, both easily available and cost-effective chemicals. The resulting iron chloride solution is successfully valorized as a hydrogen sulfide suppressor to purify the biogas generated in the anaerobic sludge treatment of a wastewater treatment plant. Additionally, we validate the NDSX mathematical model using pilot scale experimental data, providing a design tool for process scale-up and industrial implementation.

11.
J Environ Chem Eng ; 11(2): 109305, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36647535

ABSTRACT

The COVID-19 pandemic has produced a huge impact on our lives, increasing the consumption of certain pharmaceuticals, and with this, contributing to the intensification of their presence in wastewater and in the environment. This situation demands the implementation of efficient remediation technologies, among them, electrochemical oxidation (ELOX) is one the most applied. This work studies the application of ELOX with the aim of eliminate pharmaceuticals used in the fight against COVID-19, assessing its degradation rate, as well as the risk of formation of toxic trace by-products, such as unintentional POPs like polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). To this end, model solutions containing 10 mg L-1 of dexamethasone (DEX), paracetamol (PAR), amoxicillin (AMX), and sertraline (STR) with two different electrolytes (NaCl and Na2SO4) have been evaluated. However, electrochemical systems that contain chloride ions in solution together with PCDD/Fs precursor molecules may lead to the formation of these highly toxic by-products. So, PCDD/Fs were quantified under conditions of complete degradation of the drugs. Furthermore, the presence of PCDD/Fs precursors such as chlorophenols was determined, as well as the role of Cl-, Cl• and SO 4 • - radicals in the formation of the by-products and PCDD/Fs. The maximum measured concentration of PCDD/Fs was around 2700 pg L-1 for the amoxicillin case in NaCl medium. The obtained results emphasise the importance of not underestimating the potential formation of these highly toxic trace by-products, in addition to the correct selection of oxidation processes and operation variables, in order to avoid final higher toxicity in the medium.

12.
Sci Total Environ ; 868: 161376, 2023 Apr 10.
Article in English | MEDLINE | ID: mdl-36621496

ABSTRACT

Disinfection commonly follows conventional treatments in wastewater treatment and remediation plants aiming at reducing the presence of pathogens. However, the presence of the so called "micropollutants" has emerged as a serious concern, therefore developing tertiary treatments that are not only able to remove pathogens but also to degrade micropollutants is worth investigating. Nowadays, UV-C photo-degradation processes are widely used for disinfection due to their simplicity and easy operation; additionally, they have shown potential for the removal of contaminants of emerging concern. Conventional mercury lamps are being replaced by light-emitting diodes (LEDs) that avoid the use of toxic mercury and can be switched on and off with no effect on the lamp lifetime. This work aims to comparatively evaluate the performance of several photo-degradation technologies for the removal of two targeted micropollutants, the pharmaceutical dexamethasone (DXMT) and the herbicide S-metolachlor (MTLC), using UV irradiation doses typical of disinfection processes. To this end, the technical performance of UV-A/UV-C photolysis, UV-A/UV-C photocatalysis, UV-C/H2O2 and UV-C/NaOCl has been compared. The influence of operating conditions such as the initial concentration of the pollutants (3 mg L-1 - 30 mg L-1, concentrations found in membrane or adsorption remediation steps), pH (3-10), and water matrix (WWTP secondary effluent, and ultrapure water) on the degradation efficiency has been studied. The economic evaluation in terms of electricity and chemicals consumption and the carbon footprint has been evaluated. UV-C photolysis and UV-C photocatalysis appear as the most suitable technologies for the degradation of DXMT and MTLC, respectively, in terms of kinetics (1.53·10-1 min-1 for DXMT and 1.96·10-2 min-1 for MTLC), economic evaluation (1 € m-3 for DXMT and 32 € m-3 for MTLC) and environmental indicators (0.5 g-CO2 for DXMT and 223.1 g-CO2 for MTLC).

13.
Membranes (Basel) ; 12(12)2022 Nov 26.
Article in English | MEDLINE | ID: mdl-36557099

ABSTRACT

Recently, there have been several studies done regarding anion exchange membranes (AEMs) based on polyepichlorohydrin (PECH), an attractive polymer enabling safe membrane fabrication due to its inherent chloromethyl groups. However, there are still undiscovered properties of these membranes emerging from different compositions of cast solutions. Thus, it is vital to explore new membrane properties for sustainable energy generation by reverse electrodialysis (RED). In this study, the cast solution composition was easily tuned by varying the ratio of active polymer (i.e., blend ratio) and quaternary agent (i.e., excess diamine ratio) in the range of 1.07-2.00, and 1.00-4.00, respectively. The membrane synthesized with excess diamine ratio of 4.00 and blend ratio of 1.07 provided the best results in terms of ion exchange capacity, 3.47 mmol/g, with satisfactory conductive properties (area resistance: 2.4 Ω·cm2, electrical conductivity: 6.44 mS/cm) and high hydrophilicity. RED tests were performed by AEMs coupled with the commercially available Neosepta CMX cation exchange membrane (CEMs).

14.
Comput Struct Biotechnol J ; 20: 5886-5901, 2022.
Article in English | MEDLINE | ID: mdl-36382192

ABSTRACT

Lipopolysaccharide (LPS), a main component of the outer membrane of Gram-negative bacteria, has crucial implications on both antibiotic resistance and the overstimulation of the host innate immune system. Fighting against these global concerns calls for the molecular understanding of the barrier function and immunostimulatory ability of LPS. Molecular dynamics (MD) simulations have become an invaluable tool for uncovering important findings in LPS research. While the reach of MD simulations for investigating the immunostimulatory ability of LPS has been already outlined, little attention has been paid to the role of MD simulations for exploring its barrier function and synthesis. Herein, we give an overview about the impact of MD simulations on gaining insight into the shield role and synthesis pathway of LPS, which have attracted considerable attention to discover molecules able to surmount antibiotic resistance, either circumventing LPS defenses or disrupting its synthesis. We specifically focus on the enhanced sampling and free energy calculation methods that have been combined with MD simulations to address such research. We also highlight the use of special-purpose MD supercomputers, the importance of appropriate LPS and ions parameterization to obtain reliable results, and the complementary views that MD and wet-lab experiments provide. Thereby, this work, which covers the last five years of research, apart from outlining the phenomena and strategies that are being explored, evidences the valuable insights that are gained by MD, which may be useful to advance antibiotic design, and what the prospects of this in silico method could be in LPS research.

15.
Chemosphere ; 307(Pt 3): 135991, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35963376

ABSTRACT

Recalcitrant contaminants are not usually removed in conventional wastewater treatment plants. Therefore, they are transferred to the water resources that receive treated wastewaters and their presence can cause health and environmental issues. Herbicides are among these compounds. In particular, S-metolachlor (MTLC) is specifically of high concern because its molecule incorporates a chlorine atom that contributes to its toxicity. For its removal, a magnetically recoverable photocatalyst, TiO2/Fe3O4/rGO-5, was synthesised following a hydrothermal method. The performance of TiO2/Fe3O4/rGO-5 has been experimentally assessed and compared to TiO2 and TiO2/rGO-5 catalysts. A characterisation of the materials properties was carried out including adsorption isotherms of MTLC that provided the maximum adsorption capacity of the materials (qm), being 140.85 ± 5.14 mg g-1 for TiO2/Fe3O4/rGO-5. Furthermore, the ternary composite exhibited good recoverability from liquid media after four consecutive cycles thanks to its magnetic character (magnetic saturation of 13.85 emu g-1). Photocatalytic degradation of MTLC started after a dark adsorption step following first order kinetics (0.0197 ± 1.2 × 10-4 min-1 for the degradation of 100 mg L-1 of MTLC with 0.5 g L-1 of TiO2/Fe3O4/rGO-5) similar to the rate of appearance of chloride in solution; after total removal of the solubilized MTLC the chloride concentration in the solution continued increasing with zero-th order kinetics up to the value corresponding to the total MTLC concentration. This second step in the chloride formation was attributed to the degradation of adsorbed MTLC. Specific experiments in the presence of scavengers of reactive oxygen species (ROS) were carried out shedding light on the degradation mechanisms. It was concluded the predominant role of free hydroxyl radicals in the photocatalytic degradation in all the investigated materials, whereas the presence of rGO in the composite photocatalysts improved their electronic conductivity, enhancing the activity of superoxide radicals. The results of this work provide important information for further development of photocatalysis.


Subject(s)
Herbicides , Wastewater , Acetamides , Catalysis , Chlorides , Chlorine , Graphite , Reactive Oxygen Species , Superoxides , Titanium
16.
Sci Total Environ ; 847: 157368, 2022 Nov 15.
Article in English | MEDLINE | ID: mdl-35843323

ABSTRACT

Aquaculture has been the fastest growing agricultural sector in the past few decades and currently supplies about half of the fish market. A range of environmental and management concerns including limited land and water availability have led to intensifying fish production by recirculating aquaculture systems (RAS). Fish's diet contains 30-60 % protein and about 4-10 % nitrogen (N). As fish assimilate only 20-30 % of the feed to produce body mass, the unassimilated N is released in the form of toxic ammonium that deteriorates water quality and compels its degradation. Widely extended biological nitrification is not efficient in the removal of nitrites nor other chemicals and pharmaceuticals used during fish culture. Electrochemical oxidation, a less developed alternative, reports several advantages such as, i) simultaneous degradation of ammonia­nitrogen (TAN) and water disinfection in the same step with considerable simplification of the whole process, ii) easy adaptability to different production scales and periods of fish growth, and iii) no generation of harmful by-products and no use of chemicals, among others. Besides, in the case of marine aquaculture, the technology benefits from the high conductivity of seawater; thus, electrochemical oxidation is positioned in a very good place to satisfy the water treatment needs of the increasing production rate of marine aquaculture fish. Here, we report the analysis of the performance of a RAS demonstration plant aimed at farming gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) and provided with electrochemical remediation of culture water. The performance of the plant, with 20 m3 of seawater operating at a recirculation rate of 0.9-1.4 h-1, has been analysed in terms of TAN removal, water disinfection, make-up water intake and energy consumption and compared to data of conventional RAS provided with biofilters. The benefits and advantages of the innovative electrochemical remediation of RAS water are highlighted.


Subject(s)
Ammonium Compounds , Bass , Sea Bream , Animals , Ammonia , Aquaculture , Nitrites , Nitrogen , Pharmaceutical Preparations
17.
Ind Eng Chem Res ; 61(18): 6106-6124, 2022 May 11.
Article in English | MEDLINE | ID: mdl-35578731

ABSTRACT

The recovery of energy and valuable compounds from exhaust gases in the iron and steel industry deserves special attention due to the large power consumption and CO2 emissions of the sector. In this sense, the hydrogen content of coke oven gas (COG) has positioned it as a promising source toward a hydrogen-based economy which could lead to economic and environmental benefits in the iron and steel industry. COG is presently used for heating purposes in coke batteries or furnaces, while in high production rate periods, surplus COG is burnt in flares and discharged into the atmosphere. Thus, the recovery of the valuable compounds of surplus COG, with a special focus on hydrogen, will increase the efficiency in the iron and steel industry compared to the conventional thermal use of COG. Different routes have been explored for the recovery of hydrogen from COG so far: i) separation/purification processes with pressure swing adsorption or membrane technology, ii) conversion routes that provide additional hydrogen from the chemical transformation of the methane contained in COG, and iii) direct use of COG as fuel for internal combustion engines or gas turbines with the aim of power generation. In this study, the strengths and bottlenecks of the main hydrogen recovery routes from COG are reviewed and discussed.

18.
Sci Total Environ ; 820: 153189, 2022 May 10.
Article in English | MEDLINE | ID: mdl-35051482

ABSTRACT

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.


Subject(s)
Greenhouse Gases , Hydrogen , Animals , Greenhouse Effect , Life Cycle Stages , Ships , Vehicle Emissions/analysis
19.
Ind Eng Chem Res ; 60(46): 16780-16790, 2021 Nov 24.
Article in English | MEDLINE | ID: mdl-34866775

ABSTRACT

The design of microdevices in which components with magnetic character must be separated and recovered from reactive media benefits from the advantages of microfluidics and meets the criteria for process intensification; however, there are open questions, such as the design of the most appropriate magnet arrangement, that need further research in order to increase the magnetic gradient exerted on the particles. Herein, we focus on the continuous recovery of magnetic microparticles, that can be used as support to facilitate the recovery of biocatalysts (magnetic microcatalysts, MMCs) from biological fluids. We analyze and compare the performance of two typical magnetophoretic microdevices for addressing bead recovery: (i) annular channels with a quadrupole orientation of the permanent magnets (quadrupole magnetic sorter, QMS) and (ii) the standard design, which consists of rectangular channels with a single permanent magnet to generate the magnetic field. To this end, an experimentally validated computational fluid dynamics (CFD) numerical model has been employed. Our results reveal that for devices with the same width and length, the micro-QMS, in comparison to a rectangular channel, could accomplish the complete particle retrieval while (i) processing more than 4 times higher fluid velocities, treating more than 360 times higher flow rates or (ii) working with smaller particles, thus reducing by 55% the particle mass. Additionally, the parallel performance of ≈300 micro-QMSs fulfills the processing of flow rates as high as 200 L·h-1 while entirely capturing the magnetic beads. Thereby, this work shows the potential of the QMS advanced design in the intensification of the recovery of catalysts supports of magnetic character.

20.
J Chem Inf Model ; 61(10): 4839-4851, 2021 10 25.
Article in English | MEDLINE | ID: mdl-34559524

ABSTRACT

Lipopolysaccharide (LPS) is the primary component of the outer leaflet of Gram-negative bacterial outer membranes. LPS elicits an overwhelming immune response during infection, which can lead to life-threatening sepsis or septic shock for which no suitable treatment is available so far. As a result of the worldwide expanding multidrug-resistant bacteria, the occurrence and frequency of sepsis are expected to increase; thus, there is an urge to develop novel strategies for treating bacterial infections. In this regard, gaining an in-depth understanding about the ability of LPS to both stimulate the host immune system and interact with several molecules is crucial for fighting against LPS-caused infections and allowing for the rational design of novel antisepsis drugs, vaccines and LPS sequestration and detection methods. Molecular dynamics (MD) simulations, which are understood as being a computational microscope, have proven to be of significant value to understand LPS-related phenomena, driving and optimizing experimental research studies. In this work, a comprehensive review on the methods that can be combined with MD simulations, recently applied in LPS research, is provided. We focus especially on both enhanced sampling methods, which enable the exploration of more complex systems and access to larger time scales, and free energy calculation approaches. Thereby, apart from outlining several strategies for surmounting LPS-caused infections, this work reports the current state-of-the-art of the methods applied with MD simulations for moving a step forward in the development of such strategies.


Subject(s)
Bacterial Infections , Sepsis , Bacterial Outer Membrane , Humans , Lipopolysaccharides/toxicity , Molecular Dynamics Simulation , Sepsis/drug therapy
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