79 results about "Nitrous acid" patented technology

The invention relates to the technical field of analytical chemistry, in particular to an ion chromatography method for separation and detection of acetate, nitrite and nitrate ions in a complex matrix culture medium. The method mainly solves the problems of insufficient separation degree, serious matrix interference, poor detection precision and reproducibility and the like when the conventional ion chromatography technology is used for detecting a complex matrix culture medium.

The invention belongs to the technical field of sludge dewatering, and particularly relates to a sludge acidification conditioning dewatering method. Comprising the following steps: adjusting the pH value of the sludge to 2-4, then adding a nitrite solution, uniformly mixing, standing for reaction so as to generate free nitrous acid in the system, and carrying out selective oxidative degradation, moisture release, filtration and dehydration on extracellular polymeric substances of the sludge through the free nitrous acid, thereby obtaining the dewatered sludge. According to the method, free nitrous acid with a certain concentration is generated in a sludge system under the combined action of an acidification environment and nitrite, and the free nitrous acid is used for breaking sludge extracellular polymeric substances and releasing water adsorbed and wrapped by sludge flocs, so that the dehydration performance of the sludge is remarkably improved, and the dehydration efficiency is improved.

The present invention addresses the problem of providing an acidic cleaning solution for an aluminum-based metallic material, the acidic cleaning solution being capable of suppressing foaming while achieving favorable cleaning properties. One embodiment for solving the aforementioned problem is an acidic cleaning solution for an aluminum-based metallic material that comprises 0.01-25 g / L of at least one inorganic acid selected from the group consisting of sulfuric acid, nitric acid, nitrous acid, and phosphoric acid; 0.05-4.0 g / L of trivalent iron ions; and 0.1-10 g / L of a surfactant, wherein the surfactant includes a surfactant A: a polyoxyalkylene alkyl ether having a cloud point of 80°C or more, a surfactant B: a polyoxyalkylene alkyl ether having a cloud point of 50-60°C, and a surfactant C: a polyoxyalkylene alkyl ether having a cloud point of 40°C or less, and wherein the cloud point is measured in accordance with JIS K 3211: 1990.

A nitrogen-based gas discharge device 100 according to one aspect of the present invention includes: a green compact 111 containing a powder of a layered double hydroxide in which nitrite ions (NO2 -) are included between layers, and a powder of a reducing agent or a precursor thereof; and a gas discharge module 110 disposed so as to cover the green compact 111 and composed at least of a film 112 that is waterproof and has water vapor permeability and gas permeability. The solubility of the reducing agent in water at room temperature is 1 g / 30 mL or more and the pH of a 0.1 (w / v)% aqueous solution of the reducing agent at room temperature is 5.1 or less. The nitrogen-based gas discharge device 100 may also include a water-containing body 120 for supplying water vapor to the nitrogen-based gas discharge module 110.

The invention discloses a preparation method and application of a ruthenium-silver-based catalyst, the prepared catalyst constructs a porous microenvironment, a pore confinement silver site is utilized to adsorb nitrite generated by nitric acid conversion, a high-concentration nitrite local environment is further formed, a ruthenium site is responsible for catalytic conversion of nitrite, and the ruthenium site is responsible for catalytic conversion of nitrite. And finally, energy-saving and high-efficiency ammonia preparation is realized.

The application provides a gas-phase rust-proof oil and a preparation method and a rust-proof method thereof, and is characterized in that the gas-phase rust-proof oil comprises 60-80 parts by weight of base oil, 5-20 parts by weight of an oil-soluble sulfonate rust-proof agent and 3-15 parts by weight of a gas-phase corrosion inhibitor; wherein the gas-phase corrosion inhibitor comprises a first gas-phase corrosion inhibitor and a second gas-phase corrosion inhibitor; the weight ratio of the first gas-phase corrosion inhibitor and the second gas-phase corrosion inhibitor is 1-6:1; the first gas-phase corrosion inhibitor is selected from an amine with a morpholine structure; the second gas-phase corrosion inhibitor is different from the first gas-phase corrosion inhibitor and is selected from at least one of an amine with a benzene ring structure, an amine with a nitrous acid structure and an amine with a carboxylic acid structure; the gas-phase rust-proof oil of the application not only has excellent salt spray rust-proof performance and gas-phase rust-proof performance, but also does not separate for a long time, and the appearance is transparent and turbid; in the method for preparing the gas-phase rust-proof oil, the process temperature is lower than 50 DEG C, the energy consumption is low, the production process is simple, and the time consumption is less.

The invention discloses a method and a device for rapidly measuring the concentration of various inorganic anions in water. According to the method, rapid and high-precision colorimetric detection of eight ions such as fluorine ions, chloride ions, nitrite ions, bromide ions, nitrate ions, phosphate radicals, sulfite radicals and sulfate radicals is realized by adopting a reaction strategy of adding a color developing auxiliary agent and a specific color developing agent step by step and combining with step-by-step uniform mixing and optimizing a reagent combination, a concentration ratio and a reaction time sequence aiming at different target ions. The device comprises a sample groove, a multi-cavity color developing agent bin, a color developing auxiliary bin, a reaction tank, a liquid path conveying module, an image acquisition module and a control module which are integrated in a shell. Through deep integration of a chemical system and an automatic process, the problems of cross interference, poor color development stability, complicated operation and the like in multi-index detection of portable equipment are solved, and the method has the advantages of high detection speed, high accuracy, strong anti-interference performance, easiness in carrying and simplicity and convenience in operation.

The invention relates to a surface modified Fe / Cu-Co3O4 catalyst for nitrite detection and a preparation method thereof, a sensor and application, and the preparation method comprises the following steps: dissolving a cobalt source, an iron source, a copper source, urea and NH4F in deionized water, carrying out a hydrothermal reaction, washing, drying and calcining to obtain a Fe and Cu co-doped Co3O4 nanotube; and pre-hydrolyzing by using a KH792 silane coupling agent ethanol-water solution, and reacting with nanotubes to prepare the surface modified catalyst. The sensor takes carbon cloth or a screen-printed electrode subjected to ultrasonic cleaning and plasma treatment as a substrate, catalyst ink is coated to form a catalytic layer, and the catalytic layer, a platinum counter electrode and a silver / silver chloride reference electrode form a three-electrode system. Through molecular modification and material design, the interfacial force between the catalyst and nitrite is improved, the electrode stability is enhanced, and the catalyst is applied to a disposable printed electrode and portable detection equipment, so that high-sensitivity, stable and portable detection of nitrite is realized.

The present invention discloses a method for transferring non-polar hydroxyapatite to a polar organic solution phase. The method comprises: redispersing HAP prepared by a hydrothermal method in cyclohexane, adding DMF in an equal volume to the cyclohexane, adding nitrosium tetrafluoroborate under stirring conditions, and after vigorous stirring, HAP spontaneously transfers from the cyclohexane phase to the DMF phase. During the ligand exchange process, NO in nitrosium tetrafluoroborate is converted to hydroxyapatite. + Unstable and easily converted into NO2 + , nitrous acid, tetrafluoroboric acid. NO + A large number of conversions in a short period of time will leave a large amount of BF4 in the system ‑ and protons, these acidic protons react with COO ‑ Combined with, reduce the strong coordination effect between oleic acid and Ca element on the surface of HAP particles, thereby promoting BF4 ‑ The present invention uses nitrosium tetrafluoroborate to remove oleic acid from the surface of HAP nanoparticles, BF4 ‑ The electrostatic repulsion effect ensures the uniform dispersion of HAP nanoparticles in DMF. This method is simple to operate and has high transfer efficiency, further expanding the application prospects of HAP nanoparticles.

The invention discloses a method for reducing inhibition of free nitrous acid on toxicity of microalgae, and belongs to the technical field of biology and new medicine. In order to solve the problem that free nitrous acid (FNA) in a microalgae-nitrifying bacteria co-culture system destroys a microalgae photosynthetic system and inhibits growth, alpha-ketoglutaric acid with the final concentration of 0.5-1.0 mM is exogenously added into the microalgae-nitrifying bacteria co-culture system, so that carbon and nitrogen metabolism of microalgae is regulated and controlled, the tolerance of the microalgae to FNA is enhanced, the photosynthetic efficiency and biomass of the microalgae are remarkably improved, and the microalgae-nitrifying bacteria co-culture system can be used for preparing the microalgae-nitrifying bacteria co-culture system. The ammonia nitrogen removal rate and the system stability are improved; the method is easy and convenient to operate, low in cost, suitable for high-ammonia-nitrogen wastewater treatment and capable of assisting long-term stable operation of a phycomycete symbiotic system.

[Problem] To provide a nitrogen fixation method and a nitrogen fixation device which are capable of significantly reducing energy and cost and are easy to put into practical use. [Solution] According to the present invention, water 14, which is brought into contact with air and has dissolved the air, is brought into contact with a photocatalyst (photocatalyst layer 5), and the photocatalyst is irradiated with ultraviolet rays (light source 91), and thus ammonia, nitric acid, or nitrous acid is generated in the water 14 from nitrogen molecules in the air dissolved in the water 14 by a photocatalytic reaction.

A method of manufacturing a plating solution comprising a platinum (II) complex, comprising the steps of: (i) preparing an acidic aqueous solution comprising a chloride-free platinum (IV) compound and a source of nitrous acid (HNO2) as a reducing agent; (ii) heating the solution from step (i) in order to promote the reduction of platinum (IV) to platinum (II) and decomposition of residual nitrous acid. Also described is a platinum plating solution produced by this process.

The utility model relates to gas monitoring technology, specifically provide gaseous nitrous acid analyzer, including sampling unit, separation unit and analysis unit connected in proper order, gaseous nitrous acid analyzer still includes the absorption unit connected separation unit gas export, the absorption unit includes: the both ends of jar body open, and both ends are inserted upper cover and lower cover respectively, upper cover and lower cover have gas passage respectively, sealing ring is around the outside of jar body radial, and is arranged between jar body and upper cover, and between jar body and lower cover, the filler bag is arranged in jar body, and anhydrous sodium carbonate is filled in the filler bag, the gasket is arranged in the axial direction of jar body, is extruded by upper cover and jar body one end end, and is extruded by lower cover and jar body other end end, the utility model has the advantages such as good airtightness.

The present invention discloses an electrochemical microsensor, comprising: a device substrate; a bottom layer of polyimide formed on the device substrate; a top layer of polyimide formed on the top surface of the bottom layer of polyimide and designed to match the pattern of a working electrode lead, a reference electrode and its lead, and a counter electrode and its lead; a silver mirror film formed on the top surface of the top layer of polyimide, respectively constituting the working electrode lead, the reference electrode and its lead, and the counter electrode and its lead; and a working electrode, which is nitrogen-oxygen co-doped laser-induced graphene formed on the bottom layer of polyimide and conductively connected to the working electrode lead. A method for preparing an electrochemical microsensor and its application for detecting nitrous acid are disclosed. The present invention has the beneficial effects of good conductivity, low detection limit, stable performance, high reusability, and a wide range of applications.

The application discloses a preparation method of nitrophenol, which comprises the following steps: taking a nitrous acid compound as a nitro source, and reacting the nitrous acid compound with a phenol compound in a solvent under the catalysis of an acyl chloride or an anhydride catalyst to generate the nitrophenol. The application has the advantages of wide application range of substrates, mild reaction condition, short reaction time, simple operation, no use of strong acid and metal catalyst, environmental friendliness, excellent yield, and the like, and the yield can reach 95%.

The utility model relates to gas monitoring technology, specifically provide miniaturized gaseous nitrous acid analyzer, including analysis unit, the analysis unit includes light source module, flow cell and detection module, the analysis unit still includes: first optical fiber and second optical fiber have ceramic plug core and optical fiber joint respectively, ceramic plug core connects one end of three -way joint respectively, and optical fiber joint connects light source module and detection module respectively, flow cell includes composite pipe and switching module, the composite pipe includes glass tube and protection tube, glass tube sets up in the inside of protection tube, switching module connects glass tube and protection tube, and fixes on the other end of three -way joint, first ceramic plug core, first three -way joint, first switching module, composite pipe, second switching module, second three -way joint and second ceramic plug core are in straight line and set gradually. The utility model has the advantages of miniaturization, convenient maintenance etc.

The invention discloses a mass correction factor-based soluble methyl nitrite content determination method and a mass correction factor-based soluble methyl nitrite content determination system, and belongs to the technical field of methyl nitrite content determination. According to the method, an alcohol substance is adopted as a reference substance, a reliable bridge is provided for indirect quantification, and the problems that a conventional reference substance is poor in compatibility and prone to volatilization or hydrolysis are solved; secondly, an indirect quantitative system of the gaseous correction factor and the liquid reference content is established, the content of the methyl nitrite can be accurately measured without a dissolved methyl nitrite standard sample for the first time, and the technical problem that direct quantification is difficult due to lack of a special liquid standard substance in the prior art is solved.

The invention develops an axial weak coordination synthesis method for regulating and controlling a cobalt phthalocyanine molecular metal d band center based on a graphdiyne topological structure. The method is characterized in that a series of graphdiyne two-dimensional interfaces with different topological structures are obtained by regulating and controlling the arrangement and proportion of sp-and sp-hybridized carbon atoms, and the adsorption configuration of cobalt phthalocyanine molecules along the graphdiyne topological structure two-dimensional interfaces is regulated by utilizing the d-pi action between sp-carbon and a cobalt metal center. The weak coordination regulation effect of sp-carbon on the d band center of cobalt phthalocyanine metal is realized. In the process of preparing hydroxylamine from nitrate through electro-catalysis, the adsorption energy of hydroxylamine at the Co-N4 site is reduced through the axial weak coordination effect of sp-carbon; sp-carbon can be used as a transfer station for catalyzing nitrate to nitrite to assist the nitrite to be reduced into hydroxylamine at the cobalt phthalocyanine Co-N4 site, so that a full-chain series catalytic mechanism is formed.

The invention relates to the field of atmospheric environment monitoring and high-altitude sampling, and discloses an atmospheric trace nitrous acid and formaldehyde profile detection device carried by a small aircraft and a detection method. The absorption liquid is fed into the double-channel miniature spiral trapping trap through a peristaltic pump to be mixed and contacted with the sample gas to form a sample solution; a liquid storage bottle is arranged on the automatic sample disc, and the top of the first liquid inlet needle is connected with a liquid outlet of the dual-channel miniature spiral trapping trap; a color developing solution in the color developing solution storage bottle is injected into the liquid storage bottle through a second liquid inlet needle, and the constant-temperature reaction kettle controls the color developing reaction temperature to form a sample solution to be detected; a to-be-detected sample solution is pumped into the absorption cell through the liquid pumping needle, and the liquid pumping needle is driven by the liquid pumping arm to move up and down; the absorption cell is connected with a detector, and the detector is used for detecting the component concentration of the sample solution to be detected; the automatic sampler and the rapid reaction detector comprise the same automatic sample disc to realize rapid sample transfer.

The present invention relates to a method for treating an effluent from a nitriding line by membrane electrodialysis, the method comprising the application of an electric voltage between the anode and the cathode of an electrodialysis device for separating alkali metal cations and anionic species selected from nitrates, hydroxides, nitrites, carbonates and mixtures thereof.

The invention relates to a method for a palladium-catalyzed cyclization extension reaction of butadienes. Specifically, under the condition that tert-butyl nitrite is oxidized under the catalysis of palladium, the cyclopentanone compound is obtained through a ring extension reaction of butyl fulvene and water. According to the invention, green and rich water is used as a raw material, and a series of cyclopentanone compounds are obtained under mild conditions.

The invention discloses a preparation method of 4-bromophenylhydrazine hydrochloride, and relates to the technical field of organic synthesis, and the preparation method comprises the following steps: S1, diazotization: mixing 4-bromoaniline and concentrated hydrochloric acid, adding a sodium nitrite aqueous solution under a stirring condition, and reacting to obtain a reaction solution; step S2, reduction: adding concentrated hydrochloric acid and ammonium sulfite into the reaction liquid obtained in the step S1, reacting, separating out crystals, and filtering; s3, salifying: dissolving a product obtained after filtering in the step S2 in concentrated hydrochloric acid, stirring at 80-85 DEG C until crystals are separated out, and performing suction filtration and drying to obtain 4-bromophenylhydrazine hydrochloride; in the diazotization process in the step S1, the speed of adding the sodium nitrite aqueous solution is controlled to be 70-85 mL / min in the stirring process. By controlling the adding speed of the sodium nitrite, the speed of the sodium nitrite aqueous solution is controlled to be 70-85 mL / min, so that the diazonium salt decomposition caused by high sodium nitrite adding speed and excessive nitrous acid in the reaction is avoided, and meanwhile, the diazotization reaction time can be reasonably shortened.

This invention provides a copper etching solution, its preparation method, etching method, and application. The copper etching solution comprises 1-30 parts cerium ammonium sulfate, 0-20 parts inorganic acid, 0-20 parts organic acid, and 0-90 parts water. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid. The copper etching solution of this invention exhibits good etching properties for copper and minimal damage to nickel-chromium alloys.

The present disclosure relates to a system adapted to convert gaseous nitrous acid into gaseous nitric oxide. The system includes a catalytic converter and a nitric oxide analyzer. The catalytic converter includes a polytetrafluoroethylene tube and one or more concentric tubes or high surface substrates made of sulfonated tetrafluoroethylene-based fluoropolymer-copolymer positioned within the polytetrafluoroethylene tube.

A method for extracting copper from sulphide mineral ore, comprising the following steps: stacking the ore to form a pile (heap), a leaching step, irrigating the pile with a first irrigating solution containing an acidic nitrate solution and nitrite, thereby causing the oxidation of sulfide minerals inside the pile, oxidation of gaseous nitrogen oxide released during the oxidation of sulfide minerals inside the pile with oxygen to form nitrogen dioxide, and hydrolysis of nitrogen dioxide to form nitric acid and / or nitrous acid in the first irrigating solution inside the pile, to continue the leaching stage and reduce nitrogen oxide losses from the pile.

The invention belongs to the field of chemical synthesis, and particularly relates to a preparation method of 2-bromo-5-trifluoromethylpyrimidine. According to the method, isoamyl nitrite is used as a nitroso donor, benzyltrimethylammonium bromide is used as a bromine source, and 5-trifluoromethyl-2-aminopyrimidine is used as a raw material to synthesize the target product 2-bromo-5-trifluoromethylpyrimidine. The method is simple in reaction condition and high in yield, and the yield can reach 65%. In addition, the invention further provides a preparation method capable of remarkably improving the reaction yield by adding trifluoroacetic acid, and the yield is 94% or above.

The application relates to the technical field of nitrite synthesis, and discloses a synthesis method and a synthesis device of alkyl nitrite. The synthesis method comprises the following steps: firstly, mixing gaseous nitric oxide and gaseous oxygen to obtain a mixture through a first reaction; and then, mixing the mixture with alkyl alcohol to obtain alkyl nitrite through a second reaction. The synthesis method greatly shortens the reaction time, increases the yield of alkyl nitrite, does not have a complicated post-treatment process and a large amount of by-product nitric acid, and is beneficial to cost saving and time saving.

The invention relates to a preparation method of 3-bromo-2-methyl-6-methylsulfonyl benzaldoxime, and belongs to the technical field of pesticides. The preparation method comprises the following steps: by taking 2, 3-dimethyl-4-methylsulfonyl bromobenzene as a raw material and adopting an organic solvent, adding a metal salt catalyst and N-hydroxyphthalimide, dropwise adding n-butyl nitrite into a system at a certain temperature, carrying out a heat preservation reaction after dropwise adding, and carrying out post-treatment after the reaction is finished, so as to obtain the 3-bromo-2-methyl-6-methylsulfonyl benzaldoxime. According to the invention, the dosage of the oximation reagent n-butyl nitrite is reduced, and the yield of oximation reaction is improved. According to the method, the reaction conditions are mild, low-temperature dropwise adding and high-temperature reaction are converted into normal-temperature reaction, meanwhile, the reaction time is shortened, and the production energy consumption is reduced.

Provided is an immunochromatographic device and a method for measuring a sugar chain antigen in a sample, which enables measurement with sufficient sensitivity by performing nitrous acid extraction treatment for a sufficient period of time. The test strip has a sample pad, a labeled body region, and a detection region, and has a neutralizing reagent region upstream of the labeled body region and a region in which a solid acid reagent or nitrite is impregnated upstream of the neutralizing reagent region, wherein (i) the immunochromatographic device has a relatively large sample addition port for holding an added sample solution of the sample and facilitating extraction of the sugar chain antigen by the nitrite and the solid acid reagent by supplying it to the region in which the solid acid reagent or nitrite is impregnated for a short period of time; and (ii) there is no gap between the sample addition port and the sample pad, so that the sample does not overflow from the addition port, and the sample addition port has a size that enables 10 to 200 μL of the sample solution of the sample to be supplied at one time.

The invention provides a method for rapidly stabilizing and improving the denitrification efficiency of a shortcut nitrification coupled anaerobic ammonia oxidation (PN / A) system, and aims to stabilize a continuous packed fixed bed PN / A reactor in a mainstream state and improve the denitrification performance of the continuous packed fixed bed PN / A reactor at the same time. 2.0 mg N / L of free nitrous acid (FNA) and 30.0 mg N / L of free ammonia (FA) are used for treating and inhibiting nitrite oxidizing bacteria (NOB) in the system so as to reduce the concentration of nitrate nitrogen (NO3 <->-N) in effluent, and 3.0 mg N / L of FNA needs to be used for further inhibiting the nitrate nitrogen (NO3 <->-N) when the high aeration flow speed (30 mL / min) is adopted. Experiments show that by means of the method, nitrate nitrogen in effluent is reduced from 15.64 mg N / L to 3.10 mg N / L, and the total nitrogen removal rate is increased from 143.43 mg N / L / d to 589.25 mg N / L / d and is increased by 4.11 times. Besides, the reactor used in the invention is a continuous filler fixed bed reactor, so that the sewage treatment load is improved, the sludge biomass retention capability is good, the operation is simple, and the method is environment-friendly. The overall efficiency of the sewage treatment system is greatly improved, the stability of the continuous PN / A system is also improved, and the continuous PN / A system is suitable for sewage treatment scenes with efficient denitrification requirements.