Academic literature on the topic 'Gas Poisoning'

Background and Objectives: Carbon Monoxide (CO) poisoning is a leading cause of injury and death due to poisoning in many parts of the world. Among numerous sources of CO, the gas water heater can be a potential under looked source causing an accidental Carbon monoxide poisoning. In the perspective of Kathmandu valley, where there are houses with small bathrooms, inadequate ventilation and absent CO detectors, gas water heaters can be extremely dangerous even if it liberates small amount of CO gas. Herein, we present a case of CO poisoning to increase awareness about the gas water heater use and the possible risk of CO poisoning in our community.Presentation of Case: A 34 years old healthy female from Patan, presented with the history of loss of consciousness for 15 minute while taking bath on a gas water heater. There was no spontaneous respiration, no cardiac activity and her body temperature was below normal.Discussion: CO is toxic to all aerobic forms to life. CO binds to hemoglobin 230 times faster than oxygen causing cellular hypoxic damage and death. CO poisoning is not uncommon in our society and many such cases are misdiagnosed for some other illness.Conclusion: Use of the gas water heaters and likelihood of CO poisoning should be notified as a public concern. People need to be aware of these hazards to prevent fatal events and likely death due to exploitation of gas water heaters. Janaki Medical College Journal of Medical Sciences (2017) Vol. 5(2): 56-59

Liquefied petroleum gas on combustion with deficient oxygen produces toxic carbon monoxide. It is used as a fuel to heat water in gas geysers. Here, we report a fatal case of carbon monoxide poisoning resulting from the usage of gas water heater. A 24-year-old female had gone to take bath in a bathroom where a gas geyser was installed to heat the water. As she did not come out of the bathroom even after more than an hour, the door was broken down by the relatives and she was found dead. Cherry red postmortem hypostasis, congested and edematous pinkish lungs, and cerebral edema were salient autopsy findings. Carboxyhemoglobin was quantified in blood to 76.55%. The cause of death was attributed to carbon monoxide poisoning; accidental in manner. This case highlights the hazards of using a gas geyser in an ill-ventilated bathroom.

Sewer gas (H2S) is a toxic gas generally produced naturally by decaying organic matter. Death in sewer gas poisoning is due to respiratory arrest. Acute exposure of Hydrogen sulphide causes cytochrome oxidase enzyme inhibition causing disruption of oxidative metabolism and affecting nervous system and cardiac tissue immediately. It affects almost all system like, CNS, respiratory, cardiovascular, renal, gastrointestinal, dermal and ocular system. The powerful effect of hydrogen sulphide over olfactory inhibition makes the people unaware to its characteristic rotten egg odour. Rarely hydrogen sulphide poisoning occurs by intention but most of the case is accidental. Hydrogen sulphide is highly toxic and flammable gas, and, because of heavier than air it is accumulated at the bottom of poorly ventilated and closed space. In India it is observed that most of the sewer cleaning is done manually and the workers are not aware to its harmful effect because of lack of knowledge, so they unfortunately comes under its silent dangerous effect. There are standards and guidelines for exposure of hydrogen sulphide at work place; if it is followed and proper safety measures are taken then incidence will be reduced. Here we are reporting a series of four cases of accidental sewer gas poisoning, the autopsy of which were done in our mortuary, AIIMS, New Delhi.

Zinc phosphide has been used widely as a rodenticide. Upon ingestion, it gets converted to phosphine gas in the body, which is subsequently absorbed into the bloodstream through the stomach and the intestines and gets captured by the liver and the lungs. Phosphine gas produces various metabolic and nonmetabolic toxic effects. Clinical symptoms are circulatory collapse, hypotension, shock symptoms, myocarditis, pericarditis, acute pulmonary edema, and congestive heart failure. In this case presentation, we aim to present the intensive care process and treatment resistance of a patient who ingested zinc phosphide for suicide purposes.

Carbon monoxide (CO) is a product of combustion of organic matter in the presence of inadequate supply of oxygen. Common sources are burning fuel, engine exhaust, burning of animal dung, heater emissions and gas geyser. It is a toxic, clear, colorless and tasteless gas. The clinical presentation runs a spectrum, ranging from headache and dizziness to coma and death. Here we report three cases that presented to us in the month of November 2023 with history, sign & symptoms suggestive of CO poisoning. Bangladesh Crit Care J March 2024; 12 (1): 72-74

Currently, the number of cases of carbon monoxide poisoning continues to remain high. The article provides examples of the occurrence of carbon monoxide and the reasons for its accumulation in the room. According to statistics, in Russia gas poisoning ranks second in the structure of causes of death from acute poisoning of chemical etiology. Over the 6 months of 2023, 19 cases of poisoning were registered, 6 of which (31.6 %) resulted in the death of the victims. In the structure of violent death (8078 cases), fatal poisoning ranks third after mechanical injuries and mechanical asphyxia and accounts for 6.3 % (513 cases). The article presented measurements and calculations from which conclusions were drawn about the immediate causes of the formation of carbon monoxide in the room. Data from technical examinations and world literature on CO poisoning were studied and analyzed. It was found that the most common reasons for the formation of carbon monoxide in the premises were insufficient air exchange in the premises, the use of mechanical ventilation systems in apartments where this was not provided, the inoperability of ventilation ducts, the shutdown of gas equipment safety systems and violations in the installation of gas equipment. This article also provides recommendations that will allow defending yourself and your loved ones from the danger of carbon monoxide poisoning. The problem of carbon monoxide is global; in order to prevent poisoning from combustion products, everyone needs to know the rules for using gas equipment and the basic principles of air exchange.

In South Korea, deaths caused by poisoning are mostly suicides due to drug overdoses, or agrochemical poisonings. Even though the latter is becoming less frequent, they are still occurring in large numbers across the country. In some cases, deaths result from toxicity of organic solvents contained in the agrochemical products. In this study, we identified organic solvents in post-mortem blood of acute agrochemical poisoning cases using solid phase microextraction-gas chromatography/mass spectrometry with black fiber. Out of 42 cases, organic solvents were detected in 29, with toluene and butanol detected simultaneously in 13 cases. In these 13 cases, the original pesticides were of various types, including organophosphorus compounds, carbamate, nicotine, and oxadiazine. Xylene and ethyl benzene were simultaneously detected six times. In these six cases, the original pesticides were mainly pyrethroid-based pesticides, such as cypermethrin and deltamethrin. Methoxypropanol was detected in five cases in which the water-soluble pesticide glufosinate was detected. These organic solvents may cause acute poisoning and even death in some agrochemical poisoning cases.

Abstract The aim of this thesis project was to gain new knowledge on the effect of phosphorus on the catalytic activity and characteristics of automotive exhaust gas catalyst components. The simultaneous roles of phosphorus and calcium were also studied. The first test series of powdery catalyst samples contained Rh and oxide (Test series 1) and the second, Pt and oxide or ZSM-5 (Test series 2). The catalysts were analyzed when fresh and after two ageing and phosphorus poisoning procedures developed in this work. The procedures consisted of adding poison via impregnation in an aqueous solution (for Test series 1) and in the gaseous phase under hydrothermal conditions (for Test series 2). The poison compounds formed and the changes in the washcoat were studied by using physisorption analyses, SEM, TEM, XRD, and FTIR-ATR. The poison content of the samples was determined by ICP-OES and XRF. Laboratory-scale activity measurements were done to investigate the catalytic activity. Thermodynamic calculations were used to obtain information about ageing conditions and phosphorus compounds formed during ageing. Phosphorus decreased the catalytic activity and the characteristic surface areas of the catalysts. Addition of calcium to a phosphorus-poisoned catalyst was found to have even a regenerating effect on the catalysts' activity. The poisoning methods developed in this study resulted in the same phosphorus compounds as can be found in vehicle-aged catalysts. Phosphorus was identified as cerium, zirconium, aluminium, and titanium phosphates. Phosphorus was detected in zeolites, but phosphorus-containing compounds were not observed. Phosphorus poisoning takes place in the gas phase at high operating temperatures and with high oxygen and water contents. It was also shown that the role of phosphorus poisoning was more pronounced than the role of hydrothermal ageing alone. Phosphorus poisoning mainly affects the oxide components used in this study, not the noble metals. The results can be utilized in the development of catalytic materials and catalyst compositions that can better tolerate phosphorus poisoning under hydrothermal conditions. The results can also be applied in evaluating the effects of phosphorus on different catalyst compositions and in estimating the age of commercial catalysts.

This work provides a detailed characterization study on H2S poisoning of Pd and Pd/Au alloy composite membranes to obtain fundamental understandings of sulfur poisoning phenomena and preparation of sulfur tolerant membranes. The enhancement of the sulfur tolerance by alloying Pd with Au has been confirmed by both permeation test and microstructure analysis (SEM and XRD). While pure Pd membranes exhibited the permeance decline in the presence of H2S due to both sulfur adsorption and bulk Pd4S formation, Pd/Au alloy membranes showed the permeance loss merely resulted from the surface sulfur adsorption without bulk sulfide formation up to 55 ppm H2S. The XPS study confirmed that the H2S adsorption on the Pd/Au alloy surfaces was dissociative, and both surface Au and Pd sulfides were formed with the preferential Au-S bonding. The adsorption type of sulfur on the Pd/Au alloy surfaces was monolayer with a limited coverage, which increased with decreasing temperature. The permeance loss of Pd/Au membranes was essentially fully recoverable in H2, and the integrity of the membranes remained unaltered after the poisoning/recovery tests. Increasing Au composition in the Pd/Au membranes increased the sulfur tolerance. A Pd/Au alloy membrane of 16.7 wt% Au exhibited a permeance over 50% of its original value in the presence of 5 ppm H2S at 400°C, while a Pd membrane showed 85% permeance loss. The Pd/Au alloy membranes were fabricated by the Au displacement deposition, which had an empirical reaction order of 3.2 determined by the AAS. The HT-XRD study verified that the formed Pd/Au alloy layers were thermally stable up to 500°C.

[EN] Several major problems have to be solved before Solid Oxide Fuel Cells (SOFC) can operate continuously using hydrocarbon fuels such as natural gas. The risk of low catalytic behavior for fuel reforming, the carbon formation/deposition on the anode material at high operating temperatures and the presence of impurities in the fuel (in particular sulfides) can dramatically reduce the performance and durability of the cells. Taking all this into account, new anode materials with adequate (electro)catalytic properties are required. Recently, manganite compounds with Ruddlesden-Popper (RP) structure have been studied as potential new anode materials in INTERFASE group at Universidad Industrial de Santander (UIS). Their electrochemical performance have been described in previous works with promising results, but a fundamental knowledge was missing concerning the catalytic properties of such materials and the way to improve them by the addition of nickel metallic particles on the electrode surface. The current Ph.D. thesis was focused on the synthesis, characterization and catalytic study for steam reforming in SOFC anode conditions (low steam content) of a new RP manganite (La1.5Sr1.5Mn1.5Ni0.5O7±δ), which, in reducing atmosphere at high operating temperatures promotes via an exsolution mechanism the formation of two phases, i.e. an RP manganite of composition LaSrMnO4±δ decorated with metallic active Ni nanoparticles embedded in the surface; such strategy can be viewed as an original way to improve the (electro)catalytic properties of the anode materials and then a promising option for future SOFC systems operating with Colombian natural gas. The first chapter deals with the synthesis and characterization of the RP n= 2 phase La1.5Sr1.5Mn1.5Ni0.5O7±δ using the Pechini method. In agreement with SOFC operating temperature, Ni exsolution has been studied in diluted H2 at different temperatures (750, 800 and 850 °C) and reduction times. Ni nanoparticles decorating an RP n= 1 manganite is confirmed by XRD, TEM-EDS analysis and the size of the metallic particles on the oxide surface, below 100 nm, is characterized as a function of the exsolution conditions. The second chapter presents the catalytic behavior for the methane steam reforming reaction of the exsolved material applying the Gradual Internal Reforming concept adapted to SOFC operation (i.e. low water content, steam to carbon ratio equal to 0.15) at different reaction temperatures (750, 800 and 850 °C). The catalytic properties of Ni impregnated samples using a similar (La,Sr)2MnO4±δ ceramic support are also presented for comparison. The exsolved material exhibits better performance than the impregnated manganite for the reaction, especially at 850 °C, with higher conversion, conversion rate, and H2 production rate. Concerning the steam reforming of light alkane gas mixtures (CH4-C2H6, and CH4-C3H8), the behavior is affected due to the competition between the molecules and low available metallic active sites, but without affecting the H2 production. In addition, at long reaction times, the activity over the exsolved material is stable even with 100 h of reaction, without formation of carbonaceous species on the Ni particles, as confirmed by TEM and TGA/MS analysis. In the third and last chapter, the possible coke formation and sulfide poisoning are presented. Despite the high and stable catalytic behavior for methane steam reforming reaction with considerable carbon formation resistance, the exsolved material exhibits a high level of sensitivity to H2S poisoning, similar to the case of state-of-the-art Ni/YSZ anodic cermet and or Ni impregnated catalyst, with a drop of the activity to almost zero. Nevertheless, the exceptional overall results obtained for the exsolution-based material are promising for a possible use as SOFC anode operating with sulfur-free Colombian natural gas.
[ES] Muchos son los problemas que deben resolverse antes de que las celdas de combustible de óxido sólido (SOFC por sus siglas en inglés) puedan operar continuamente usando combustibles hidrocarbonados como por ejemplo el gas natural. El riesgo de una baja actividad catalítica para el reformado del combustible, la formación y depósito en el material de ánodo a elevadas temperaturas de operación y la presencia de impurezas en el combustible empleado (en particular de sulfuros) pueden reducir dramáticamente el desempeño y la durabilidad de las celdas. Teniendo todo esto en cuenta, nuevos materiales de ánodo con adecuadas propiedades (electro)catalíticas son necesarios. Recientemente, en el grupo INTERFASE de la Universidad Industrial de Santander (UIS), compuestos de tipo manganita con estructura Ruddlesden-Popper (RP) han sido estudiados como potenciales materiales de ánodo. Su desempeño electrocatalítico ha sido descrito en trabajos previos con promisorios resultados, pero el conocimiento fundamental sobre las propiedades catalíticas de dichos materiales y la forma de mejorarlos mediante la adición de partículas metálicas de níquel en la superficie del electrodo aún faltaba. La presente tesis doctoral se enfocó en la síntesis, caracterización y estudio catalítico en el reformado con vapor en condiciones de ánodo de celdas SOFC (bajo contenido de vapor) de una nueva manganita de tipo RP (La1.5Sr1.5Mn1.5Ni0.5O7±δ), la cual, en atmósfera reductora y a elevadas temperaturas de operación, promueven a través del mecanismo de exsolución la formación de dos fases: una manganita tipo RP de composición LaSrMnO4±δ decorada con nanopartículas metálicas y activas de Ni incrustadas en la superficie; dicha estrategia puede ser vista como una manera muy original de mejorar las propiedades (electro)catalíticas de los materiales de ánodo y por lo tanto ser consideradas como una opción prometedora para sistemas SOFC operados con gas natural colombiano. El primer capítulo trata sobre la síntesis de la fase RP n= 2 La1.5Sr1.5Mn1.5Ni0.5O7±δ usando el método de Pechini y su caracterización. De acuerdo con la temperatura de operación de las celdas SOFC, la exsolución del Ni en atmósfera de H2 diluido a diferentes temperaturas (750, 800 y 850 °C) y tiempos de reducción fue estudiada. Las nanopartículas de Ni decorando la manganita de estructura RP n= 1 es confirmada a través de análisis de DRX, MET-EDS y el tamaño de las partículas metálicas en la superficie del óxido, inferiores a 100 nm, es caracterizado en función de las condiciones de exsolución. El segundo capítulo presenta el comportamiento catalítico del material exsuelto en la reacción de reformado de metano aplicando el concepto de reformado interno gradual (GIR por sus siglas en inglés) adaptado a celdas SOFC (en otras palabras, bajo contenido de agua, relación vapor carbono igual a 0.15) a diferentes temperaturas de reacción (750, 800 y 850 °C). Las propiedades catalíticas de las muestras impregnadas con Ni utilizando como soporte un material cerámico similar (La,Sr)2MnO4±δ, son también presentados como comparación. El material exsuelto exhibe un mejor desempeño catalítico en la reacción de reformado que la manganita impregnada, especialmente a 850 °C, mostrando una más alta conversión, velocidad de conversión y de producción de H2. Con respecto al reformado de la mezcla de alcanos ligeros (CH4 -C2H6, y CH4 -C3H8), el comportamiento catalítico es afectado debido a la competición entre moléculas y la baja disponibilidad de sitios activos metálicos, sin afectar la producción de H2. Adicionalmente, a tiempos de reacción prolongados, la actividad en el material exsuelto es estable incluso con 100 h de reacción, sin formación de especies carbonáceas sobre las partículas de Ni como lo confirman las imágenes MET y el ATG/MS. En el tercer y último capítulo, la posible formación y depósito de carbón y el envenenamiento con sulfuros son presentados. Sin embargo, a pesar de la elevada y estable actividad catalítica en la reacción de reformado de metano con vapor con una considerable resistencia a la formación de carbón, el material exsuelto tiene un alto nivel de sensibilidad al envenenamiento con H2S, similar al Ni/YSZ (material de referencia de la literatura) o al material impregnado con Ni, con una disminución de la actividad catalítica a prácticamente cero No obstante, el excepcional resultado global obtenido en el material exsuelto es prometedor para un posible uso como material de ánodo en sistemas SOFC alimentados con gas natural colombiano libre de H2S.
[CA] Molts són els problemes que han de ser resolts abans que les cel·les de combustible d'òxid sòlid (SOFC per les seues sigles en anglès) puguen operar contínuament usant combustibles hidrocarbonats com per exemple el gas natural. El risc d'una baixa activitat catalítica per al reformat del combustible, la formació i depòsit en el material d'ànode a elevades temperatures d'operació i la presència d'impureses en el combustible emprat (en particular de sulfurs) poden reduir dramàticament l'acompliment i la durabilitat de les cel·les. Tenint tot això en compte, nous materials d'ànode amb propietats (electro)catalítiques adequades són necessaris. Recentment, en el grup d'investigació INTERFASE de la Universitat Industrial de Santander (UIS), compostos de tipus manganita amb estructura Ruddlesden-Popper (RP) han sigut estudiats com a potencials materials anòdics. El seu acompliment electroquímiques ha sigut tractades en treballs previs amb resultats promissoris, però el coneixement fonamental sobre les característiques catalítiques d'aquests materials i la manera de millorar-los mitjançant l'addició de partícules metàl·liques de níquel en la superfície de l'elèctrode encara faltava. La present tesi de doctorat es va enfocar en la síntesi, caracterització i estudi d'activitat catalítica en el reformat amb vapor en condicions d'ànode de cel·les SOFC (sota contingut de vapor) d'una nova manganita de d'estructura RP (La1.5Sr1.5Mn1.5Ni0.5O7±δ), la qual, en atmosfera reductora i a elevades temperatures d'operació, promouen, a través del mecanisme de exsolució; la formació de dues fases: una manganita de composició LaSrMnO4±δ decorada amb nanopartícules metàl·liques i actives de Ni incrustades en la superfície; aquesta estratègia pot ser vista com una manera molt original de millorar les propietats (electro)catalítiques dels materials d'ànode i per tant, ser considerades com una prometedora opció per a futurs usos en sistemes SOFC alimentats amb gas natural colombià. El primer capítol tracta sobre la síntesi de la fase RP n= 2 La1.5Sr1.5Mn1.5Ni0.5O7±δ usant el mètode de Pechini i la seua caracterització. D'acord amb la temperatura d'operació de les cel·les SOFC, la exsolució del Ni en atmosfera d'H2 diluït a diferents temperatures (750, 800 i 850 °C) i temps de reducció va ser estudiada. Les nanopartícules de Ni decorant la manganita d'estructura RP n= 1 és confirmada a través d'anàlisi de DRX, MET-EDS i la grandària de les partícules metàl·liques en la superfície de l'òxid, inferiors a 100 nm, és caracteritzat en funció de les condicions de exsolució. El segon capítol presenta el comportament catalític del material d’exsolució en la reacció de reformat de metà amb vapor aplicant el concepte de reformat gradual intern (GIR per les seues sigles en anglès) adaptat a cel·les SOFC (en altres paraules, sota contingut de vapor, relació vapor-carboni de 0.15) a diferents temperatures de reacció (750, 800 i 850 °C). Les propietats catalítiques de les mostres impregnades amb Ni utilitzant com a suport un material ceràmic similar (La,Sr)2MnO4±δ, són també presentats com a comparació. El material d’exsolució exhibeix un millor resultat catalític en la reacció de reformat que la manganita impregnada, especialment a 850 °C, mostrant una més alta conversió, velocitat de conversió i de producció d'H2. En el reformat de la mescla d'alcans lleugers (CH4 -C2H6, i CH4 -C3H8), el comportament catalític és afectat per la competició entre molècules i la baixa disponibilitat de llocs actius metàl·lics, sense afectar la producció d'H2. Addicionalment, a temps de reacció llargs, l'activitat en el material d’exsolució és estable fins i tot desprès de 100 h de reacció, sense formació d'espècies carbòniques sobre les partícules de Ni, com ho confirmen les imatges MET i el ATG/MS. En el tercer i últim capítol, la possible formació i depòsit de carbó i l'enverinament amb sulfurs són presentats. No obstant això, malgrat l'elevada i estable activitat catalítica en la reacció de reformat de metà amb vapor amb una considerable resistència a la formació de carbó, el material d’exsolució té un alt nivell de sensibilitat a l'enverinament amb H2S, similar al Ni/YSZ (material de referència de la literatura) o el material impregnat amb Ni, amb una disminució de l'activitat catalítica a pràcticament zero No obstant això, l'excepcional resultat global obtingut aquest nou material és prometedor per a un possible ús futur com a material d'ànode en sistemes SOFC alimentats amb gas natural colombià lliure d'H2S.
Al Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS) por la beca de estudios de Doctorados Nacionales Conv. 647 y el proyecto # 110265842833 “Symmetrical high temperature Fuel Cell operating with Colombian natural gas”. Al Consejo Superior de Investigaciones Científicas por el apoyo con la ayuda económica para la estancia mediante la convocatoria I-coop Project # COOPA20112.
Vecino Mantilla, JS. (2020). Nickel exsolution effect on the catalytic behavior of ruddlesden-popper manganites in sofc conditions using colombian natural gas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/149474
TESIS

The goal of current solid oxide fuel cell (SOFC) research is to design electrode materials and other system components that permit the fuel cell to be operated in the 400-700ºC range. Cell performance in this lower temperature range is limited by the oxygen reduction process at the SOFC cathode and by multiple contamination processes. The work presented demonstrates that Raman spectroscopy, a form of vibrational spectroscopy, can provide structural and compositional information complementary to that from traditional characterization methods. Initial experiments into the oxygen reduction mechanism on SOFC cathodes were unable to detect surface oxygen species on selected perovksite-based SOFC cathode materials. However, the Raman signal from the cathode surface was able to be enhanced by depositing silver or gold nanoparticles on the cathode, creating the so-called surface-enhanced Raman scattering (SERS) effect. The Raman sample chamber was also used to study two possible electrode contamination processes. First, the deposition of carbon on nickel and copper anodes was observed when exposed to different hydrocarbon fuel gases. Second, the poisoning of an SOFC cathode by chromium-containing vapor (usually generated by stainless steel SOFC system components) was monitored. Overall, Raman spectroscopy was shown to be useful in many areas crucial to the development of practical, cost-effective SOFCs. The techniques developed here could also be applied to other high temperature electrochemical and catalytic systems.

Climate change has become a discussion topic of exponentially increasing urgency and importance amoung world leaders of all disciplines. These changes are brought about by the emission of so-called Greenhouse gases from various human activities. The primary cause of CO2 emissions is the burning of the Earth’s supply of nonrenewable natural fossil fuels like coal, oil and natural gas. The world first agreed on the prevention of “dangerous” climatic changes at the Earth Summit in 1992. The Kyoto Protocol of 1997 was the first step toward protection of the atmosphere and prescribes restrictions on emission pollutants. Since then the vehicle gas emissions are being controlled by means of different gas emissions norms, like the European Union Norm in Europe. The automotive manufacturers and suppliers are collectively working on reducing overall vehicle emissions. They are focusing on several different emission limiting possibilities, for example improved engine design, special fuel development and exhaust gas treatment systems. The exhaust gas treatment process requires continuous controlling and management of the exhaust gas emissions while driving a vehicle. Certain factors such as high emission temperatures have a negative influence on the life span of these systems. Their functionality and durability is also known to be reduced by the presence of chemical poisoning species like sulphur, phosphorus, zinc and calcium. The chemical poisoning species are produced during combustion of fuel and engine oil. They are therefore contained in the exhaust emissions and can poison the catalyst when passing over it. Phosphorous poisoning is particularly problematic and should be reduced considerably. This study involves the investigation of the phosphorous poisoning process and aims to provide clarity regarding the influences of different fuel and oil compositions on the severity of the process. Engine oil and biodiesel are two major sources of phosphorous poisoning. The phosphorus contained in biodiesel fuel is a natural component and can be minimized during the refining procedure. In contrast to others studies, the biodiesel fuel used during this project was SME (Soya Methyl Ester) with a 20% biodiesel content. This choice of fuel was made because of the increasingly important role that this type of biodiesel is playing in the European market and the future tendency to increase the percentage of biodiesel in the mixture with standard diesel fuel. The phosphorus contained in engine oil is a necessary additive to retain the antioxidant and anti-wear properties of the oil. This study examined the poisoning influences from the most commonly used phosphorus containing oil additive, Zinc Dithiophosphates (ZDDP), as well as a Zn-free, phosphorus containing anti-wear oil additive. This formulation provides information about the phosphorus poisoning process as caused by the engine oil in the absence of Zn in the oil additives. The results show how the phosphorus content in biodiesel fuel affects the functionality of the exhaust gas treatment systems and the importance of reducing the permitted content of phosphorus contained in the fuel. Reducing the phosphorus content in the fuel will conserve the functionality of the exhaust gas treatment systems during their operational life and thereby protect the environmental from emission pollutants. It also provides insight into the differences in the poisoning processes when the phosphorus deposited on the catalyst comes from biodiesel fuel and when it comes from the engine oil. Finally the results also illustrate the influence of different phosphorous forms contained in engine oil additives on the catalyst poisoning process. This information could be used for the development of new oil additive formulations.

Abstract The combustion of fuels in motor vehicles is one of the most significant causes of air emissions. The use of oxidation catalysts in exhaust gas emission treatment can reduce hydrocarbons (HCs) and carbon monoxide (CO) emissions by more than 90%. Fuels and engine lubricants contain impurities like sulphur (S) and phosphorus (P), which can have a significant effect on the activity and durability of oxidation catalysts. This thesis aims at increasing the current knowledge of the deactivation phenomena caused by sulphur and phosphorus in diesel and natural/bio gas oxidation catalysts. Accelerated laboratory scale sulphur, phosphorus and thermal treatments in gas-phase conditions were carried out for alumina (Al2O3) based platinum (Pt) and platinum-palladium (PtPd) metallic monolith diesel and natural gas oxidation catalysts. In addition, a vehicle-aged natural gas oxidation catalyst and an engine-bench-aged diesel oxidation catalyst were studied and used as a reference for the laboratory-scale-aged catalysts. BET-BJH, FESEM, TEM, XPS and DRIFT were used as characterization techniques to determine changes on the catalysts. The effect of accelerated deactivation treatments on the catalyst activity was determined using laboratory scale measurements in CO, HC and nitric oxide (NO) oxidation. Sulphur and phosphorus were found to cause morphological and chemical changes on the studied catalysts. Sulphur was found to be adsorbed vertically throughout the entire catalyst support from the catalyst surface to the metallic monolith, while phosphorus accumulated on the surface region of the precious metal containing catalysts. Both, sulphur and phosphorus, slightly increased the average size of the precious metal particles size and are adsorbed onto the alumina by chemical bonds. In addition, a partial transformation from PdO to Pd and a change in the shape of the precious metal particles due to phosphorus were detected. Due to the detected structural and chemical changes on the catalysts, sulphur and phosphorus treatments reduced the catalytic activity of the studied diesel and natural-gas-oxidation catalysts. Correspondence between real and simulated ageing was found and thus the used accelerated laboratory scale aging method can be stated to be a good tool to simulate sulphur and phosphorus exposure
Tiivistelmä Moottoriajoneuvot ovat merkittäviä ilmapäästöjen aiheuttajia. Hapetuskatalyyttejä käyttämällä hiilimonoksidi- ja hiilivetypäästöistä pystytään poistamaan yli 90 %. Polttoaineet ja voiteluaineet sisältävät epäpuhtauksia kuten rikkiä ja fosforia, jotka voivat merkittävästi heikentää hapetuskatalyyttien aktiivisuutta ja kestävyyttä. Väitöskirjan tavoitteena on tuottaa uutta tietoa rikin ja fosforin aiheuttamasta diesel- ja maakaasukatalyyttien deaktivoitumisesta. Metalliseen monoliittiin tuettuja alumiinioksidipohjaisia platina- ja palladiumkatalyytteja ikäytetiin tekemällä niille rikki-, fosfori- ja lämpökäsittelyjä. Maantieikäytettyä maakaasuhapetuskatalyyttiä ja moottoripenkki-ikäytettyä dieselhapetuskatalyyttiä käytettiin laboratorioikäytettyjen katalyyttien referensseinä. Ikäytyskäsittelyjen aiheuttamat muutokset analysoitiin BET-BJH-, FESEM-, TEM-, XPS- ja DRIFT-menetelmillä. Käsittelyjen vaikutus katalyyttien hiilimonoksidin, hiilivetyjen ja typenoksidien hapetusaktiivisuuteen tutkittiin laboratoriomittakaavan aktiivisuuslaitteella. Rikki ja fosfori aiheuttivat rakenteellisia ja kemiallisia muutoksia tutkittuihin katalyytteihin. Rikki adsorboitui koko tukiaineeseen (tukiaineen pinnalta pohjalle), kun taas fosfori adsorboitui vain pinnan alueelle. Sekä rikki että fosfori kasvattivat jalometallipartikkeleiden kokoa sekä muodostivat alumiinioksidin kanssa yhdisteitä. Lisäksi fosforikäsittelyjen havaittiin osittain pelkistävän PdO:n Pd:ksi ja muuttavan jalometallipartikkelien muotoa. Havaitut rikin ja fosforin aiheuttamat rakenteelliset sekä kemialliset muutokset laskivat diesel- ja maakaasukatalyyttien hapetusaktiivisuutta. Laboratorioikäytyksillä havaittiin olevan hyvä korrelaatio todellisissa olosuhteissa tehtyjen ikäytysten kanssa ja tästä syystä työssä käytetyn laboratoriomittakaavan ikäytysmenetelmän voidaan todeta olevan hyvä työkalu simuloimaan rikin ja fosforin aiheuttamaa deaktivoitumista

Abstract Summary Critical care physicians frequently manage poisoning and drug overdose. Poisoning and overdose may cause respiratory failure by compromising respiratory pump function and/or by causing direct injury to the lung parenchyma. Respiratory failure may also develop from central nervous system depression. In poisonings associated with respiratory failure, arterial blood gas should always be done with co-oximetry. Airway, Breathing, Circulation, Disability, Exposure (ABCDE) remains the mainstay of initial approach but may need to be modified in certain poisoning and overdoses where oxygen therapy may aggravate toxicity or where specific therapy, that is, antidote, may improve respiratory failure dramatically. Decontamination and supportive measures remain the main focus of treatment.

Carbon monoxide (CO) exposure has been described ever since humans developed products of combustion (e.g. fire, burning charcoal). The Romans realized that CO poisoning leads to death (Penney 2000). Coal fumes were used in ancient times for execution, and the deaths of two Byzantine emperors are attributed to CO poisoning (Lascaratos and Marketos 1998). Admiral Richard E. Byrd developed CO poisoning during the winter he spent alone in a weather station deep in the Antarctic interior (Byrd 1938). Further, CO poisoning took the life of tennis player Vitas Gerulaitis (“Died, Vitas Gerulaitis,” 1994; Lascaratos and Marketos 1998) and may have contributed to Princess Diana’s accidental death in 1997 (Sancton and Macleod 1998). Carbon monoxide is a colorless, tasteless, odorless gas by-product of the combustion of carbon-containing compounds such as natural gas, gasoline, kerosene, propane, and charcoal. The most common sources of CO poisoning are internal combustion engines and faulty gas appliances (Weaver 1999). Carbon monoxide poisoning can also occur from space heaters, methylene chloride in paint removers, and fire (Weaver 1999). The most frequent causes of pediatric CO poisoning are vehicle exhaust, dysfunctional gas appliances and heaters, and charcoal briquettes (Kind 2005; Mendoza and Hampson 2006). Less common sources of CO poisoning include riding in the back of pickup trucks, and while swimming and recreational boating (Hampson and Norkool 1992; Silvers and Hampson 1995). Among pediatric populations, minorities are disproportionately affected by CO poisoning compared to Caucasians, and Latinos and non-Latino blacks were more commonly poisoned by charcoal briquettes used for cooking or heating (Mendoza and Hampson 2006). Carbon monoxide is the leading cause of poisoning injury and death worldwide (Raub et al. 2000) and accidental and intentional poisoning in the United States. In the United States carbon monoxide poisoning results in approximately 40,000 emergency department visits (Hampson 1999) and 800 deaths per year (Piantadosi 2002). Children are particularly venerable to CO poisoning. The Center for Disease Control reports children younger than 4 years have the highest incidence of unintentional CO poisoning but the lowest death rates (2005).

Through analyzing the impact of the factors of catalyst deactivation, different factors are classified according to timeliness characteristics. In this research, experiments were made under the condition of coal combustion flue gas on a coal-fired boiler to study the characteristics of the early deactivation of the SCR catalyst. Analysis shows that the main cause of early deactivation of catalyst is chemical poisoning (mainly alkali metal) and pores clogging on the surface of the catalyst. While the main cause of long-term deactivation is deeper chemical poisoning, pores clogging and the chemical form changes of elements on the surface of the catalyst. Through analyzing the influence of the factors of catalyst deactivation, separate factors are classified according to timeliness characteristics. This research provides a strong fundamental support to clear the deactivation mechanism of the SCR catalyst.

Lean NOx trap catalysis has demonstrated the ability to reduce NOx emissions from lean natural gas reciprocating engines by >90%. The technology operates in a cyclic fashion where NOx is trapped on the catalyst during lean operation and released and reduced to N2 under rich exhaust conditions; the rich cleansing operation of the cycle is referred to as “regeneration” since the catalyst is reactivated for more NOx trapping. Natural gas combusted over partial oxidation catalysts in the exhaust can be used to obtain the rich exhaust conditions necessary for catalyst regeneration. Thus, the lean NOx trap technology is well suited for lean natural gas engine applications. One potential limitation of the lean NOx trap technology is sulfur poisoning. Sulfur compounds directly bond to the NOx trapping sites of the catalyst and render them ineffective; over time, the sulfur poisoning leads to degradation in overall NOx reduction performance. In order to mitigate the effects of sulfur poisoning, a process has been developed to restore catalyst activity after sulfur poisoning has occurred. The process is an aqueous-based wash process that removes the poisoned sorbate component of the catalyst. A new sorbate component is reapplied after removal of the poisoned sorbate. The process is low cost and does not involve reapplication of precious metal components of the catalyst. Experiments were conducted to investigate the feasibility of the washing process on a lean 8.3-liter natural gas engine on a dynamometer platform. The catalyst was rapidly sulfur poisoned with bottled SO2 gas; then, the catalyst sorbate was washed and reapplied and performance was reevaluated. Results show that the sorbate reapplication process is effective at restoring lost performance due to sulfur poisoning. Specific details relative to the implementation of the process for large stationary natural gas engines will be discussed.

The investigation studies improving PEMFC carbon monoxide by a periodic air dosing. The carbon monoxide in the fuel gas leads to a significant loss in power density due to CO poisoning in the anode. The method involves bleeding air into the anode fuel stream (H2-CO), which contains CO in various concentrations (20, 52.7, 100 ppm). In the transient CO poisoning test, air-bleeding is performed for four different periodic air dosing and cell voltage is fixed at 0.6 V. The result of a dosing of air during 10 sec in intervals of 10 sec is similar to that of continuous air-bleeding except 100 ppm CO. The CO tolerance of the fuel cell and cell performance recovery from poisoning can be improved by air-bleeding.

The PEM fuel cell has broad applications such as stationary power generation, transportation power sources and portable power generators. From commercial considerations, most anodes of PEM fuel cells use reformate gas as their fuels. However, reformate gas will have small content of carbon monoxide (CO) which will seriously poison platinum (Pt) catalyst electrode, and result in cell performance degradation significantly. The anode air-bleeding method is a preferable way to solve this CO-poisoning problem due to its simplicity, low cost and effectiveness. In this study, a test PEM fuel cell (single cell, active area 5cm × 5 cm) is assembled, its anode fuel uses hydrogen with 52.7ppm CO. Air-bleeding method then is applied to investigate and analyze the influence of CO poisoning on the performance of this PEM fuel cell.

In some regions of the world, emissions of total organic carbon (TOC), including methane and non-methane hydrocarbons (NMHCs), from the tail pipe of natural gas or biogas fuelled combustion equipments are strictly regulated (e.g. 150 mg/Nm3 of exhaust gas in Italy). Post combustor has been widely chosen in response to the TOC emission targets. TOC typically consists of >90% methane — a strong greenhouse gas and the most challenging compound to remove due to its highly stable form. Thus, more gas is being consumed to burn the TOC present in the exhaust, resulting in higher operating (or power production) costs. A passive catalytic approach is an alternative to post combustor. Palladium based oxidation catalyst is known to actively remove TOC, providing no sulfur compounds present. Sulfur poisons and deactivates the catalyst in a short time. This paper presents a concept to extend the life of the oxidation catalyst by using an exhaust post conditioning system. The system is designed to eliminate and withstand contaminants, yielding a protection to the catalyst. Consequently, the catalyst life is prolonged by about 50 times.

A polymer electrolyte membrane (PEM) fuel cell has been analyzed by applying the conservation principle to the gas channels, electrode backings, catalyst layers and polymer electrolyte. The conservation equations used are conservation of species, momentum and energy and the Nernst-Planck equation in the electrolyte. Oxygen reduction at the cathode is modeled using the Butler-Volmer equation while the adsorption, desorption and electro-oxidation of hydrogen and CO at the anode are modeled by the Tafel-Volmer and “reactant-pair” mechanism, respectively. Comparison of the anode electrochemical kinetics model to experimental data indicates that CO adsorption kinetics are Temkin. One-dimensional simulation of a PEM fuel cell operating with reformate fuel gas indicates an optimum operating pressure. Preliminary two-dimensional simulation verifies the one-dimensional assumption for mass transfer but indicates that a two-dimensional analysis is necessary for the catalyst layer.

In this paper, we experimentally studied an air breathing high temperature PEM fuel cell at steady operating conditions to investigate the effects of CO poisoning at different temperatures ranges between 120°C∼180°C. The effects of changes in temperatures with different amount of CO poisoning on the current-voltage characteristics of the fuel cell are investigated. Experimental data of this type would be very useful to develop design parameters of fuel processor based on reformate hydrocarbons. The high CO tolerance of high temperature PEM fuel cells makes it possible to use the reformate gas directly from the reformer without further CO removal. Here we considered the fact that a steam reformer is a consumer of heat and water, and fuel cell stacks are a producer of heat and water. Thus, integration of the fuel cell stack and the reformer is expected to improve the system performance. The results obtained from the experiments showed variations in current-voltage characteristics at different temperatures with different CO poisoning rates. The results will help to understand the overall system performance development strategy of high temperature PEM fuel cell in terms of current-voltage characteristics, when fed with on-site reformate hydrogen gas with variable CO concentrations.

This project is driven by concerns over excessive cylinder lubrication in large bore two-stroke cycle natural gas engines. Excessive cylinder lubrication can lead to: (1) Increased operating costs due to high lubricating oil consumption, (2) Poisoning of catalytic converters, and (3) Increased pollutant emissions. These concerns can be addressed by reexamining lubrication rates and exploring advanced lubrication techniques. Catalyst poisoning and increased pollutant emissions occur when a portion of the cylinder lubricating oil in some form is passed through the cylinder and into the exhaust system. The lubricating oil may carry over into the exhaust system unchanged, or it may react to form other compounds. In this work the focus is on identifying the scope of the problem associated with cylinder lubricating oil carryover into the exhaust system.

This project is driven by concerns over excessive cylinder lubrication in large bore two-stroke natural gas engines (LBNGE). Excessive cylinder lubrication can lead to: - Increased operating costs due to high lubricating oil consumption. - Poisoning of catalytic converters. - Increased pollutant emissions. Development of an electronically-controlled, power-cylinder lubricator (ECPCL) is a likely solution that could decrease excessive cylinder lubrication. This lubricator would optimize cylinder lubrication by controlling both the injection rate and injection timing, relative to piston position.

Addressing the public health threat posed by AMR is a national strategic priority for the UK, which has led to both a 20-year vision of AMR and a 5-year (2019 to 2024) AMR National Action Plan (NAP). The latter sets out actions to slow the development and spread of AMR with a focus on antimicrobials. The NAP used an integrated ‘One-Health’ approach which spanned people, animals, agriculture and the environment, and calls for activities to “identify and assess the sources, pathways, and exposure risks” of AMR. The FSA continues to contribute to delivery of the NAP in a number of ways, including through furthering our understanding of the role of the food chain and AMR.Thorough cooking of food kills vegetative bacterial cells including pathogens and is therefore a crucial step in reducing the risk of most forms of food poisoning. Currently, there is uncertainty around whether cooking food is sufficient to denature AMR genes and mobile genetic elements from these ‘dead’ bacteria to prevent uptake by ‘live’ bacteria in the human gut and other food environments - therefore potentially contributing to the overall transmission of AMR to humans. This work was carried out to assess these evidence gaps.

Harmful and toxic algal blooms (HABs) are a well-established and severe threat to human health, economies, and marine and freshwater ecosystems on all coasts of the United States and its inland waters. HABs can comprise microalgae, cyanobacteria, and macroalgae (seaweeds). Their impacts, intensity, and geographic range have increased over past decades due to both human-induced and natural changes. In this report, HABs refers to both marine algal and freshwater cyanobacterial events. This Harmful Algal Research and Response: A National Environmental Science Strategy (HARRNESS) 2024-2034 plan builds on major accomplishments from past efforts, provides a state of the science update since the previous decadal HARRNESS plan (2005-2015), identifies key information gaps, and presents forward-thinking solutions. Major achievements on many fronts since the last HARRNESS are detailed in this report. They include improved understanding of bloom dynamics of large-scale regional HABs such as those of Pseudo-nitzschia on the west coast, Alexandrium on the east coast, Karenia brevis on the west Florida shelf, and Microcystis in Lake Erie, and advances in HAB sensor technology, allowing deployment on fixed and mobile platforms for long-term, continuous, remote HAB cell and toxin observations. New HABs and impacts have emerged. Freshwater HABs now occur in many inland waterways and their public health impacts through drinking and recreational water contamination have been characterized and new monitoring efforts have been initiated. Freshwater HAB toxins are finding their way into marine environments and contaminating seafood with unknown consequences. Blooms of Dinophysis spp., which can cause diarrhetic shellfish poisoning, have appeared around the US coast, but the causes are not understood. Similarly, blooms of fish- and shellfish-killing HABs are occurring in many regions and are especially threatening to aquaculture. The science, management, and decision-making necessary to manage the threat of HABs continue to involve a multidisciplinary group of scientists, managers, and agencies at various levels. The initial HARRNESS framework and the resulting National HAB Committee (NHC) have proven effective means to coordinate the academic, management, and stakeholder communities interested in national HAB issues and provide these entities with a collective voice, in part through this updated HARRNESS report. Congress and the Executive Branch have supported most of the advances achieved under HARRNESS (2005-2015) and continue to make HABs a priority. Congress has reauthorized the Harmful Algal Bloom and Hypoxia Research and Control Act (HABHRCA) multiple times and continues to authorize the National Oceanic and Atmospheric Administration (NOAA) to fund and conduct HAB research and response, has given new roles to the US Environmental Protection Agency (EPA), and required an Interagency Working Group on HABHRCA (IWG HABHRCA). These efforts have been instrumental in coordinating HAB responses by federal and state agencies. Initial appropriations for NOAA HAB research and response decreased after 2005, but have increased substantially in the last few years, leading to many advances in HAB management in marine coastal and Great Lakes regions. With no specific funding for HABs, the US EPA has provided funding to states through existing laws, such as the Clean Water Act, Safe Drinking Water Act, and to members of the Great Lakes Interagency Task Force through the Great Lakes Restoration Initiative, to assist states and tribes in addressing issues related to HAB toxins and hypoxia. The US EPA has also worked towards fulfilling its mandate by providing tools and resources to states, territories, and local governments to help manage HABs and cyanotoxins, to effectively communicate the risks of cyanotoxins and to assist public water systems and water managers to manage HABs. These tools and resources include documents to assist with adopting recommended recreational criteria and/or swimming advisories, recommendations for public water systems to choose to apply health advisories for cyanotoxins, risk communication templates, videos and toolkits, monitoring guidance, and drinking water treatment optimization documents. Beginning in 2018, Congress has directed the U.S. Army Corps of Engineers (USACE) to develop a HAB research initiative to deliver scalable HAB prevention, detection, and management technologies intended to reduce the frequency and severity of HAB impacts to our Nation’s freshwater resources. Since the initial HARRNESS report, other federal agencies have become increasingly engaged in addressing HABs, a trend likely to continue given the evolution of regulations(e.g., US EPA drinking water health advisories and recreational water quality criteria for two cyanotoxins), and new understanding of risks associated with freshwater HABs. The NSF/NIEHS Oceans and Human Health Program has contributed substantially to our understanding of HABs. The US Geological Survey, Centers for Disease Control and Prevention, and the National Aeronautics Space Administration also contribute to HAB-related activities. In the preparation of this report, input was sought early on from a wide range of stakeholders, including participants from academia, industry, and government. The aim of this interdisciplinary effort is to provide summary information that will guide future research and management of HABs and inform policy development at the agency and congressional levels. As a result of this information gathering effort, four major HAB focus/programmatic areas were identified: 1) Observing systems, modeling, and forecasting; 2) Detection and ecological impacts, including genetics and bloom ecology; 3) HAB management including prevention, control, and mitigation, and 4) Human dimensions, including public health, socio-economics, outreach, and education. Focus groups were tasked with addressing a) our current understanding based on advances since HARRNESS 2005-2015, b) identification of critical information gaps and opportunities, and c) proposed recommendations for the future. The vision statement for HARRNESS 2024-2034 has been updated, as follows: “Over the next decade, in the context of global climate change projections, HARRNESS will define the magnitude, scope, and diversity of the HAB problem in US marine, brackish and freshwaters; strengthen coordination among agencies, stakeholders, and partners; advance the development of effective research and management solutions; and build resilience to address the broad range of US HAB problems impacting vulnerable communities and ecosystems.” This will guide federal, state, local and tribal agencies and nations, researchers, industry, and other organizations over the next decade to collectively work to address HAB problems in the United States.