alkali poisoning

Sluggish water dissociation kinetics on non-precious metal electrocatalysts limit the development of economical hydrogen production from water-alkali electrolysers. Here, using Co3N electrocatalyst as a prototype, we find that during water splitting in alkaline electrolyte a cobalt-containing hydroxide formed on the surface of Co3N, which greatly decrease the activation energy of water dissociation (Volmer step, a main rate-determining step for water splitting in alkaline electrolyte). Combining the cobalt ion poisoning test and theoretical calculations, the efficient hydrogen production on Co3N electrocatalyst would benefit from the favorable water dissociation on in-situ formed cobalt-containing hydroxide and low hydrogen production barrier on the nitrogen sites of Co3N...

Since the outbreak of methylmercury (MeHg) poisoning in Japan and Iraq, mercury (Hg) is classified as well-established teratogen. The Portuguese region of Aveiro faced some decades ago an environmental Hg contamination due to activities from a chlor-alkali plant. Until now, no apparent evaluation was conducted regarding prenatal exposure to Hg in this area. The main objectives of this study were to: i) assess maternal and fetal exposure to Hg in the Aveiro region using noninvasive biological matrices; ii) examine the influence of variables that may contribute to Hg exposure during pregnancy; and iii) improve knowledge regarding metal accumulation and distribution over the maternal-fetal-placental unit...

Zincian georgeite, an amorphous copper-zinc hydroxycarbonate, has been prepared by co-precipitation using acetate salts and ammonium carbonate. Incorporation of zinc into the georgeite phase and mild ageing conditions inhibits crystallisation into zincian malachite or aurichalcite. This zincian georgeite precursor was used to prepare a Cu/ZnO catalyst, which exhibits a superior performance to a zincian malachite derived catalyst for methanol synthesis and the low temperature water-gas shift (LTS) reaction. Furthermore, the enhanced LTS activity and stability in comparison to that of a commercial Cu/ZnO/Al2O3 catalyst, indicates that the addition of alumina as a stabiliser may not be required for the zincian georgeite derived Cu/ZnO catalyst...

OBJECTIVES: This retrospective study was performed to determine the incidence, demographic distribution, types and outcomes across various non-drug related poisonings among children attending a tertiary care center in south India. METHODS: All children from 0-16 years who presented to the Paediatric Emergency Department, Christian Medical College, Vellore with non-drug related poisoning from October 2004 to September 2013 were included. RESULTS: Out of the total 997 cases of poisoning, 629 (63...

Objective: To investigate and analyze the influential factors of occupational hazard acci-dents, emergency facilities and emergency management in Silicon solar cell producing enterprises, then to pro-vide scientific strategies. Methods: The methods of occupationally healthy field investigating, inspecting of ven-tilation effectiveness, setup of emergency program and wearing chemical suit were used. Results: The mainly occupational hazard accidents factors in the process of Silicon solar cell producing included poisoning chemi-cals, high temperature, onizing radiation and some workplaces...

A good catalyst for efficiently controlling NOx emissions often demands strong resistance against alkali poisoning. Although the traditional ion-exchange model, based on acid-base reactions of alkalis with Brønsted acid sites, has been established over the past two decades, it is difficult to be used as a guideline to develop such an alkali-resistant catalyst. Here we establish a self-protection mechanism of deNOx catalysts against alkali poisoning by systematically studying the intrinsic nature of alkali resistance of V2O5/HWO (HWO = hexagonal WO3) that shows excellent resistance to alkali poisoning in selective catalytic reduction of NOx with NH3 (SCR)...

Importance: Determining the national epidemiologic trends of chemical ocular burns can assist physicians and policy makers in appropriate allocation of resources for treatment and prevention. Objective: To describe the epidemiologic trends and risk factors for chemical burns of the eye. Design, Setting, and Participants: Between August 1, 2015, and April 25, 2016, data from the Nationwide Emergency Department Sample were analyzed from January 1, 2010, through December 31, 2013...

Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0...

The development of catalysts with simultaneous resistance to alkalis and sulfur poisoning is of great importance for efficiently controlling NOx emissions using the selective catalytic reduction of NOx with NH3 (SCR), because the conventional V2O5/WO3-TiO2 catalysts often suffer severe deactivation by alkalis. Here, we support V2O5 on a hexagonal WO3 (HWO) to develop a V2O5/HWO catalyst, which has exceptional resistance to alkali and sulfur poisoning in the SCR reactions. A 350 μmol g(-1) K(+) loading and the presence of 1,300 mg m(-3) SO2 do not almost influence the SCR activity of the V2O5/HWO catalyst, and under the same conditions, the conventional V2O5/WO3-TiO2 catalysts completely lost the SCR activity within 4 h...

Much research has been carried out in the last decade to convert bio-based feedstock into fuels and chemicals. Most of the research focuses on developing active and selective catalysts, with much less attention devoted to their long-term stability. This Review considers the main challenges in long-term catalyst stability, discusses some fundamentals, and presents options for their mitigation. Three main challenges are discussed: catalyst fouling, catalyst poisoning, and catalyst destruction. Fouling is generally related to the deposition of insoluble components present in the feed or formed by degradation of the feed or intermediates...

Spores of various Bacillus and Clostridium species are among the most resistant life forms known. Since the spores of some species are causative agents of much food spoilage, food poisoning, and human disease, and the spores of Bacillus anthracis are a major bioweapon, there is much interest in the mechanisms of spore resistance and how these spores can be killed. This article will discuss the factors involved in spore resistance to agents such as wet and dry heat, desiccation, UV and γ-radiation, enzymes that hydrolyze bacterial cell walls, and a variety of toxic chemicals, including genotoxic agents, oxidizing agents, aldehydes, acid, and alkali...

A case of favourable outcome of the treatment of extremely severe acute poisoning after prolonged exposure to lethal doses of methanol is reported. The complex treatment included urgent and effective elimination of the poison (multiple gastric lavage, hemodialysis), antidote therapy (administration of ethanol), correction of decompensated metabolic acidosis (alkali therapy and infusion therapy with reamberin). These measures had beneficial effect on the clinical course of poisoning and ensured its favourable outcome...

Heavy metal contamination of soils or water can lead to excessive lead (Pb) and cadmium (Cd) levels in rice. As cumulative poisons, consumption of Pb and Cd in contaminated rice may cause many toxic effects in humans. In the present study, Pb and Cd levels in rice samples from Hubei, Jiangxi, Heilongjiang, and Guangdong provinces in China were analyzed by cloud point extraction and graphite furnace atomic absorption spectrometry (GFAAS). The heavy metals in the rice samples were reacted with 8-quinolinol to form a complex at pH 9...

Bauxite tailings are a major type of solid wastes generated in the flotation process. The waste by-products caused significant environmental impact. To lessen this hazardous effect from poisonous mine tailings, a feasible and cost-effective solution was conceived and implemented. Our approach focused on reutilization of the bauxite tailings by converting it to 4A zeolite for reuse in diverse applications. Three steps were involved in the bauxite conversion: wet-chemistry, alkali fusion, and crystallization to remove impurities and to prepare porous 4A zeolite...

Novel Pt/MnO2 catalysts modified with alkali metal salts were prepared and exhibited excellent catalytic activity for formaldehyde oxidation. The effects of both cation and anion in the salts were investigated on the structure of catalysts and their catalytic activity. The Na(+) modification was demonstrated to be a facile and effective method to improve the catalysts performance for formaldehyde oxidation, but the anions remaining on the support might act as a mild poison by covering the surface active sites of manganese oxides...

A series of V2O5/CeO2 catalysts with different potassium loadings were prepared to investigate alkali deactivations for selective catalytic reduction of NOx with NH3. An alkali poisoning mechanism could be attributed to surface acidity, reducibility, and NOx adsorption/desorption behaviors. The detailed factors are as follows: (1) decrease of surface acidity suppresses NH3 adsorption by strong bonding of alkali to vanadia (major factor); (2) low reducibility prohibits NH3 activation and NO oxidation by formation bonding of alkali to vanadia and ceria (important factor); (3) active NOx(-) species at low temperature diminish because of coverage of alkali on the surfaces (minor factor); and (4) stable, inactive nitrate species at high temperature increase by generating new basic sites (important factor)...

In 1970, fish caught in the English-Wabigoon River system in northwestern Ontario, Canada, were found to be contaminated with mercury coming from a chlor-alkali plant in the province. In the 1970s, patients exhibiting some of the symptoms of the Hunter-Russell syndrome (e.g. paresthesias, visual field constriction, ataxia, impaired hearing, and speech impairment) were reported by some researchers. However attempts to diagnose the patients as suffering from methylmercury poisoning proved to be controversial...

OBJECTIVE: To investigate the pathogenic and clinical characteristics of chemical burns in recent years, so as to provide reference for its prevention and treatment. METHODS: Medical records of patients with chemical burns out of 6299 burn patients admitted to our unit from January 1992 to December 2011 were screened and retrospectively analyzed, including gender, age, onset time of the injury, pre-hospital management, injury cause, injury-causing chemicals, body site of wound, burn area and depth, complications, treatment and follow-up results...

Banish the villains to their own realm: biomass has gained widespread attention as a renewable energy source. However, commercial catalysts used in power plants (co-)fuelled by biomass are deactivated by the alkali-rich flue gas. In contrast, one of two types of active sites in a promising alkali-resistant hollandite catalyst traps alkali-metal ions to free up the catalytically active sites for the reduction of NO by NH(3).

Promoters and poisons for catalytic activity have been a subject of intensive research in both heterogeneous catalysis and electrocatalysis for decades, driven primarily by profound financial and societal implications involved because catalyzed reactions are at the center of many enterprises of chemical and petroleum industries. Consequently, there exist well-identified promoters and poisons, such as electropositive alkali elements for the former and electronegative later 2p elements for the latter, respectively...