Showing papers on "Sodium chlorate published in 2002"

Sodium chlorate supplementation reduces E. coli O157:H7 populations in cattle

Abstract: Cattle are a natural reservoir of the food-borne pathogen Escherichia coli 0157:H7 Therefore, strategies that reduce E coli 0157:H7 prior to slaughter will reduce human exposures to this virulent pathogen When bacteria that can anaerobically respire on nitrate (eg, E coli) are exposed to chlorate, they die because the intracellular enzyme nitrate reductase converts nitrate to nitrite, but also co-metabolically reduces chlorate to cytotoxic chlorite Because chlorate is bactericidal only against nitrate reductase-positive bacteria, it has been suggested that chlorate supplementation be used as a strategy to reduce E coli 0157:H7 populations in cattle prior to harvest Cattle (n = 8) were fed a feedlot-style high-grain diet experimentally infected with three strains of E coli O157:H7 Cattle were given access to drinking water supplemented with 25 mM KNO 3 and 100 mM NaCl (controls; n = 4) or 25 mM KNO 3 and 100 mM NaClO 3 (chlorate-treated; n = 4) Sodium chlorate treatment for 24 h reduced the population of all E coli 0157:H7 strains approximately two logs (10 4 to 10 2 ) in the rumen and three logs (10 6 to 10 3 ) in the feces Chlorate treatment reduced total coliforms and generic E coli from 10 6 to 10 4 in the rumen and by two logs throughout the rest of the gastrointestinal tract (ileum, cecum, colon, and rectum) Chlorate treatment reduced E coli O157:H7 counts throughout the intestinal tract but did not alter total culturable anaerobic bacterial counts or the ruminal fermentation pattern Therefore, it appears that chlorate supplementation is a viable potential strategy to reduce E coli O157:H7 populations in cattle prior to harvest

Effect of Powder Properties on the Intensity of Raman Scattering by Crystalline Solids

Abstract: The effect of particle size on Raman intensity has been measured for a number of crystalline solids with a fiber-optic-based Raman spectrometer. Particle sizes ranged from 76 to 605 μm. Materials examined were sodium nitrate, sodium chlorate, sodium bromate, potassium ferrocyanide, potassium ferricyanide, and copper(II) sulfate. Raman intensity was found to decrease with increasing particle size. The factors responsible for this trend are discussed. We conclude that the major factor is diffuse reflectance that enhances the overlap between the excitation and collection beams. The depth of sample contributing to the Raman signal has been examined for both powders and tablets as a function of powder particle size. Materials examined in this study were sodium nitrate, sodium sulfate, sodium chlorate, sodium bromate, potassium ferrocyanide, potassium ferricyanide, and copper(II) sulfate. For nonabsorbing powders, the depth of sample contributing to the signal exceeded 15 mm. The effect of the pressure used in forming tablets on the Raman signal strength and reproducibility has been examined for sodium nitrate. The Raman intensity was found to decrease with increasing pressure until a tablet of constant density was formed. The effect of particle size and particle size mismatch on the sodium nitrate Raman signal in binary mixtures with potassium chloride, potassium bromide, and potassium iodide has been examined. Good reproducibility was found to require matching of component particle sizes.

Asymmetric Synthesis of Optically Active Sodium Chlorate and Bromate Crystals

Abstract: The readily available sodium chlorate is an interesting ionic compound because, although achiral, it forms optically active crystals. When unperturbed, an aqueous solution of sodium chlorate yields a random distribution of + and − crystals on evaporation. Some chiral perturbations profoundly alter this distribution, however. These include seeding, the addition of the optically active cosolutes d-mannitol and d-sorbitol, and the energetic and chiral beta particles and positrons. The chiral weak interaction inherent in all atomic nuclei and thus atoms and molecules does not alter the distribution of + and − crystals. Stirring during evaporation, an achiral perturbation, affects the distribution of crystals in a given crystallization; when crystals from a large number of experiments are considered, however, the distribution of + and − crystals is random.

Disinfectant solution based on sodium hypochlorite, and process for preparing it

Abstract: Sodium hypochlorite disinfectant solution having a pH of between 10.1 and 10.7 and comprising from 0.021 to 5.76% (w/v) of sodium hypochlorite and, relative to the said amount of sodium hypochlorite, not more than 2% of sodium chlorate.

Siloxane–polypropyleneoxide hybrid ormolytes: structure–ionic conductivity relationships

Abstract: Siloxane-polypropyleneoxide (PPO) hybrids doped with sodium perchlorate (NaClO 4 ) obtained by the sol gel process were prepared with two PPO molecular weights (2000 and 4000 g/mol) and two sodium concentrations such as [O]/[Na] = 4 and 15 (O being the ether-type oxygen of PPO chains) The structure of these hybrids was investigated by 23 Na nuclear magnetic resonance (NMR) and X-ray absorption spectroscopy at the sodium K-edge (10718 eV) whereas complex impedance spectroscopy was used to determine their ionic conductivity Three sodium sites were determined by NMR The conjunction of NMR and X-ray absorption results allows us to identify one site in which Na is in a NaCI structure, a second one in which Na is in contact with perchlorate anions The third site is attributed to mobile sodium species in interaction with the polymeric chain The relative proportion of the different sites in the materials determines the ionic conductivity of the materials at room temperature: the largest ionic conductivity is 89 × 10 -6 Ω -1 cm -1 and is observed on the material with the larger amount (at least 85%) of sites in which sodium interacts with the polymer

Large high-purity chlorine dioxide generator and its production process

Abstract: By using sodium chlorate as oxidant and hydrogen peroxide or methanol as reductant and through reaction inside sulfuric acid medium, chlorine dioxide gas is generated. The chlorine dioxide gas is absorbed with frozen water at 5-10 deg.c in an absorption tower to prepare free and high concentration aqueous solution of chlorine dioxide. During the production, negative pressure aeration technology is adopted, and in a multi-stage reactor, material is fed continuously for reaction at negative pressure condition. The said method has the advantages of great production capacity, simple operation, low cost, high material utilization, high chlorine dioxide purity, etc. and may be used in paper pulp bleaching and disinfection in waterworks and sewage plant.

Process for preparing sodium chlorite

Abstract: A process for preparing sodium chlorite includes such steps as dissolving hydrogen peroxide and solid sodium chlorate in water, adding the resultant solution along with sulfuric acid to a ClO2 generator to generate the mixture of ClO2 and oxygen, loading the mixed absorbing liquid containing sodium hydroxide and hydrogen peroxide into an absorbing tower, adding ClO2 to the absorbing tower while escaping oxygen, and finally generating sodium chlorite. Its advantages are high output rate (more than 95%) and high purity (more than 95%) of product.

Preparation equipment of high-purity chlorinedioxide stable liquor and its preparation process

Abstract: The present invention relates to an equipment for preparing high-purity chlorinedioxide stable liuqor and its process. Said equipment is formed from two raw liquor tanks, a reactor, a purifier and two series-connected absorbers, and the interior of reactor. The purifier and absorber is respectively equipped with several gas jetting bubbling, tubes. The sodium chlorate, sulfuric acid and sodium chlroide are mixed according to a certain mixing ratio, heated and reacted in the reactor under the positive gas jetting bublbing action to produce mixed gas containing chlorinedioxide and chlorine gas.Then the mixed gas is passed through the purifier and purified by sodium chloride saturated solution, and the chlorine gas being ni the mixed gas can be reacted with sodium chlorite to produce chlorinedioxide, then the chlorinedioxide gas is fed into two series-connected absorbers, and absorbed and stabilized by mixed solution containing sodium hydroxide, sodium percarbonate and pH buffering agent to obtain stable chlorinedioxide solution whose purity can be up to 98%.

An efficient composition for bengal lights

Abstract: Fuel-oxidizer mixtures based on potassium chlorate or sodium chlorate are well known. These mixtures have interesting properties of deflagration and are often used in propellants. Drastic reactivity of alkaline chlorates with ammonium salts due to the formation of ammonium chlorate NH4ClO3, a very unstable salt, is famous. By analogy, we tested the reactivity of different molecules containing nitrogen atoms, and we found an efficient fuel-oxidizer composed of potassium chlorate and thiocarbamide. Impressive bengal lights of various colors can easily be achieved using this basic composition.

A macromolecular N,N-dichlorosulfonamide as oxidant for residual sulfides

Abstract: A redox copolymer, a macroporous poly(S/DVB) resin bearing N,N-dichlorosulfonamide groups, was used to remove residual sulfides from aqueous solutions by its oxidation to non-toxic products. The resin contains 8.2 meq active chlorine/g and shows strong oxidizing properties. It was employed in static and flow processes for treatment of sulfide solutions containing 32, 100 or 320 mg S /dm. The effects of various parameters on the reaction course have been studied (molar ratio of the reagents, alkalinity of the reaction media, flow rate in column processes). The data showed that the reactive copolymer easily oxidizes sulfides––it was possible to reduce the concentration below 10 lg S /dm. During oxidation processes the formation of two end products was confirmed––these were sulfates (in majority) and sulfur which causes the turbidity of the effluents. The reaction conditions to eliminate sulfur formation were sought. To utilize the polymer-bonded active chlorine with good efficiency, it was necessary to maintain a suitable level of alkalinity of the influx. The exhausted copolymer contained unsubstituted sulfonamide groups. It could be regenerated with a slightly acidified sodium chlorate(I) and reused for further processes. 2002 Elsevier Science Ltd. All rights reserved.

Sodium chlorate decomposition in the NaClO3-CaO2(CaO)-Mg systems

Abstract: Thermal decomposition of sodium chlorate with oxygen evolution in the NaClO 3 -CaO-Mg and NaClO 3 -CaO 2 -Mg systems was studied. NaClO 3 decomposition in a ternary system occurs at a lower temperature than in binary systemsof magnesium or of calcium oxides. Complete and concurrent NaClO 3 decomposition and metal oxidation occur for a certain molar proportion of the components of the system and within a narrow range of temperatures lying ca. 150°C below the temperature at which magnesium melts and oxidizes in air. The combustibility of sodium chlorate mixtures with calcium peroxide and magnesium was determined as a function of the ratio of the components. The low-magnesium boundary of the field of combustible compositions lies at 2.3 wt %.

Prepn of pure chlorine dioxide

Abstract: The pure chlorine dioxide is prepared by using sodium chlorate and sulfuric acid as raw material and through reaction at 50-65 deg.c while adding oxalic acid and starch as reductant. During the preparation, non-toxic catalyst is used and the prepared chlorine dioxide is non-toxic and harmless to human body.

Electrode coating and its use in the production of chlorate

Abstract: An electrolytic cell producing sodium chlorate uses an electrode, specifically an anode, having a coating of a mixed metal oxide having ruthenium oxide as an electrocatalyst, a precious metal of the platinum group or its oxide as a stability enhancer, antimony oxide as an oxygen suppressant and a titanium oxide binder. The electrocatalytic coating is about 21 mole percent ruthenium oxide, about 2 mole percent iridium oxide, about 4 mole percent antimony oxide and the balance is titanium oxide. The coating is characterized by high durability and low oxygen content in an offgas.

Producing method of 14-naphthoquinones and anthraquinones using oxidizing agent

Abstract: PURPOSE: A naphthoquinone and anthraquinone compounds is provided for accomplishing a simple process, higher yield of product and reduced cost of production by using £2+4| Diels-Alder reaction method. CONSTITUTION: A production of naphthoquinone and anthraquinone compounds is characterized in that it uses £2+4| Diels-Alder reaction process. Particularly, benzoquinone or naphthoquinone and any suitable solvent is placed into the £2+4| Diels-Alder reactor. Then, after adding 1.3-butadiene to the reactor the mixture is reacted at 60-120 deg.C and the obtained product is subjected to the dehydrogenation under a specific catalyst to form the final naphthoquinone or anthraquinone products. The dehydrogenation process is carried under oxidizing agents such as copper(I) chloride, hydrogen peroxide, sodium chlorate, sodium hydroxide, and oxygen.