1828 results about "Nitrate salts" patented technology

The invention relates to the technical field of sewage discharge treatment, and discloses a sewage low-carbon treatment system based on electrochemistry and biochar, which comprises a deep treatment filter tank, an electrochemical nitrogen and phosphorus removal device, a biochar adsorption and filtration module, an intelligent control and operation and maintenance system, a slow-release agent regulation and control module and a low-carbon and resource recycling system, the advanced treatment filter tank is used for filtering sewage impurities and particles, adsorbing and removing organic matters, reducing the content of nitrogen and phosphorus nutrient substances and adapting to the change of water quality and water quantity; the electrochemical nitrogen and phosphorus removal device is used for carrying out electrochemical reaction to remove nitrate, phosphate and fluorine ions. According to the invention, the electrochemical active reaction is combined with charcoal adsorption filtration, so that the technology greatly improves the sewage treatment efficiency, especially shows a higher removal rate when treating complex pollutants, can meet higher water quality standard requirements, and effectively overcomes the difficulty that the traditional treatment technology is difficult to remove multi-element pollutants.

The invention provides a sewage treatment carbon source adding control method, and relates to the technical field of sewage treatment, and the method comprises the following steps: obtaining water inlet parameters of a water inlet end of sewage to be treated and process parameters of a treatment section, the water inlet parameters comprising chemical oxygen demand, total nitrogen, total phosphorus and flow; the process parameters comprise the phosphate concentration at the tail end of an anaerobic tank, the nitrate concentration at the tail end of an anoxic tank, and the total nitrogen and chemical oxygen demand of inlet water of a denitrification filter tank; dynamically calculating a predicted carbon-nitrogen ratio and a predicted carbon-phosphorus ratio in real time according to water inlet parameters and the process parameters; based on the predicted carbon-nitrogen ratio, the predicted carbon-phosphorus ratio and a preset effluent quality standard, a carbon source adding point and a first carbon source adding amount are determined, and the carbon source adding point comprises at least one of an anaerobic tank, an anoxic tank and a denitrification filter tank; according to the carbon source feeding point and the first carbon source feeding amount, the carbon source feeding device is controlled to execute corresponding feeding operation, through segmented feeding and closed-loop control, COD standard exceeding caused by excessive carbon sources is avoided, and secondary pollution is effectively inhibited.

The invention discloses a fluoride salt-free nitrate-free cast iron enamel semitransparent glaze as well as a preparation method and application thereof, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, anhydrous borax, sodium carbonate, potassium carbonate, calcium carbonate, potassium feldspar, zinc oxide, lithium carbonate, zirconium silicate, titanium dioxide, aluminum oxide, trisodium phosphate, antimony oxide, magnesium carbonate and barium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and low-temperature firing adaptability, and is suitable for cast iron matrixes, the firing temperature is 740-760 DEG C, and the firing time is 2-3 hours. The method can be used for producing green and environment-friendly enamel products.

A composite catalyst includes a nickel foam and cobalt, copper, or both electrodeposited on the nickel foam. Making the composite catalyst includes contacting the nickel foam with an aqueous solution comprising copper, cobalt, or both, and electrodepositing nanodomains of copper, cobalt, or both, respectively, on the nickel foam. Electrochemically converting nitrate to ammonia includes contacting an electrode and a cathode comprising the composite catalyst in an electrochemical cell with an aqueous solution including nitrate, adsorbing the nitrate onto the copper, the cobalt, or both, reducing the nitrate to yield nitrite, and reducing the nitrite to yield ammonia.

The invention belongs to the technical field of rare earth functional materials, and particularly relates to a rare earth aluminate low-temperature magnetic refrigeration material and a preparation method and application thereof.The preparation method comprises the following steps that 1, rare earth metal nitrate and aluminum nitrate are added into water to be mixed, and a mixed solution is prepared; adding ammonia water into the mixed solution to prepare a precipitate; (2) carrying out annealing treatment on the precipitate to prepare a metal oxide; and (3) calcining the metal oxide to obtain the rare earth aluminate low-temperature magnetic refrigeration material. The rare earth aluminate which has the characteristics of stable structure, low preparation cost, strong mechanical property, high magnetic density and the like and is prepared by adopting a coprecipitation method and combining a high-temperature sintering technology has more excellent magnetocaloric properties in a low-temperature region.

The invention discloses an A-site high-entropy solid oxide fuel cell cathode material as well as a preparation method and application thereof, and provides an A-site high-entropy solid oxide fuel cell cathode material Pr < 0.2 > M < 0.2 > La < 0.2 > Ba < 0.2 > Sr < 0.2 > Co < 0.8 > Fe < 0.2 > O < 3-delta > with a perovskite phase. The preparation method comprises the following steps: S1, weighing multi-element metal nitrates, and mixing to obtain a first mixed solution; s2, dissolving ethylenediamine tetraacetic acid in ammonia water to obtain a second mixed solution; mixing the first mixed solution, the second mixed solution and citric acid to form a mixed precursor solution; s3, carrying out second heating treatment on the mixed precursor solution, and adjusting the pH value to form a gel precursor; and S4, carrying out pre-sintering treatment, third heat treatment and calcination treatment on the gel precursor to obtain a high-grade powder precursor, and carrying out ball milling and sieving treatment to obtain the A-site high-entropy solid oxide fuel cell cathode material. The cathode material is high in stability and good in chemical compatibility with a barrier layer GDC, provides high-quality mass transfer channels and active sites for O2 / O- / O2-, and has good electrochemical performance at medium and low temperatures.

The invention relates to the technical field of ozone catalysts, in particular to an iron-manganese bimetallic ozone catalyst as well as a preparation method and application thereof. The iron-manganese bimetallic ozone catalyst comprises an activated carbon carrier and an iron-manganese bimetallic oxide loaded on the activated carbon carrier, in the preparation process of the iron-manganese double-metal ozone oxidizing agent, anhydrous nitrate of ferric iron and divalent manganese is adopted and dissolved in absolute ethyl alcohol, then activated carbon is added for excessive dipping, drying and under-pressure calcination, and the iron-manganese double-metal ozone oxidizing agent can be obtained. When the ferro-manganese bimetallic ozone oxidizing agent is combined with ozone to remove refractory COD (Chemical Oxygen Demand) in advanced sewage treatment, the ferro-manganese bimetallic ozone oxidizing agent shows relatively good catalytic activity, the removal rate of the refractory COD in the advanced sewage treatment can reach 57.9 percent within 60 minutes, and the ferro-manganese bimetallic ozone oxidizing agent has a wide application prospect.

The present application provides a control method for adding a carbon source to sewage treatment, which relates to the technical field of sewage treatment, comprising the following steps: obtaining water inlet parameters of the sewage to be treated and process parameters of the treatment section, the water inlet parameters including chemical oxygen demand, total nitrogen, total phosphorus and flow rate, and the process parameters including phosphate concentration at the end of the anaerobic tank, nitrate concentration at the end of the anoxic tank, total nitrogen and chemical oxygen demand of the denitrification filter inlet; dynamically calculating and predicting the carbon-nitrogen ratio and the carbon-phosphorus ratio in real time based on the water inlet parameters and the process parameters; determining a carbon source addition point and a first carbon source addition amount based on the predicted carbon-nitrogen ratio, the predicted carbon-phosphorus ratio and a preset effluent water quality standard, the carbon source addition point including at least one of the anaerobic tank, the anoxic tank and the denitrification filter; controlling a carbon source addition device to perform corresponding addition operations based on the carbon source addition point and the first carbon source addition amount, and avoiding excessive COD caused by excessive carbon source through segmented addition and closed-loop control, thereby effectively suppressing secondary pollution.

The invention discloses a preparation method of a Co / Cu nano-alloy catalyst for reducing ammonia through electro-catalysis of nitrate, and belongs to the technical field of electro-catalysts and preparation thereof. The invention solves the problems of low Faraday efficiency and low yield in the process of converting nitrate into ammonia through electro-catalysis in the prior art. According to the invention, Cu and Co are compounded to prepare the catalyst of nitrate reduced ammonia with a nanoneedle structure, and the catalyst shows excellent Faraday efficiency and yield in nitrate reduced ammonia. A test result shows that the ammonia yield of the prepared Co / Cu nano-alloy catalyst reaches up to 16762.68 ugh <-1 > cm <-2 > and the Faraday efficiency is kept above 90% when the Co / Cu nano-alloy catalyst is in a mixed solution of 0.1 mol / L KNO3 and 1 mol / L KOH and the RHE is-0.5 Vvs.RHE. In addition, when the catalyst is at-0.4 V vs.RHE, the ammonia yield and the Faraday efficiency are kept stable during 10 cycles of the reaction.

A low-carbon near zero emission process of industrial waste water, comprising: S1: entering industrial waste water into a pre-oxidation system to improve biodegradability of organics; S2: after treatment in the pre-oxidation unit, entering the waste water into an anaerobic biological treatment system, sodium chloride and sulfate is deeply removed and carbon sources in the waste water can be used to remove the sulfate and nitrate; S3: entering water output from the anaerobic biological treatment system into a membrane concentration system and membrane concentrated solution enters a nano-filtration salt fractionation system for salt fractionation; and S4: refluxing nano-filtration concentrate solution generated by the nano-filtration salt fractionation system to the anaerobic biologic treatment system for biological desulfurization, or synthesizing the nano-filtration concentrate solution to be sodium persulfate by electro chemical methods, and refluxing proportionately to a waste water pre-oxidation system for use in-situ.

The invention provides a method for preparing a lithium slag-based molecular sieve by melting lithium slag with assistance of eutectic salt, and relates to the technical field of molecular sieves. The method comprises the following steps: carrying out acid pickling pretreatment on a lithium slag raw material to obtain pretreated lithium slag; co-grinding and uniformly mixing the pretreated lithium slag and eutectic salt, and reacting at 200-350 DEG C for 2-6 hours to obtain eutectic lithium slag; carrying out aging treatment and crystallization treatment on the eutectic lithium slag, carrying out solid-liquid separation, washing the solid to be neutral, and drying to obtain a lithium slag-based molecular sieve; wherein the eutectic salt comprises an alkali solvent and an auxiliary salt, the alkali solvent is sodium hydroxide, and the auxiliary salt is at least one of chlorine salt, villiaumite, carbonate, sulfate and nitrate; the molar ratio of the alkali flux to the auxiliary salt is (4-19): 1. According to the method, the eutectic salt system is introduced in the lithium slag alkali fusion stage, meanwhile, the molar ratio of the alkali flux to the auxiliary salt in the eutectic salt is controlled to be (4-19): 1, the alkali fusion reaction temperature is reduced, the reaction of the lithium slag and alkali is promoted, the molecular sieve yield is increased, the product morphology can be regulated and controlled, and a specific molecular sieve can be formed in a guiding mode.

The invention discloses silver powder with a high twin crystal ratio and a preparation method and application of the silver powder with the high twin crystal ratio. The preparation method comprises the following steps that S1, a carboxylic acid coordination agent is added into a silver source solution, and a silver precursor solution is obtained; sequentially adding a dispersing agent and an initiator into the reducing agent solution to obtain a reaction base solution; s2, a silver precursor solution is added into the reaction base solution for an oxidation-reduction reaction, then curing is conducted, and mixed mother liquor is obtained; s3, the mixed mother liquor is filtered, washed, dispersed and dried, and then the silver powder with the high twin crystal proportion is obtained; the initiator comprises one or more of sulfate, carbonate and nitrate; through the synergistic effect of the initiator and the carboxylic acid coordination agent, the silver ion release rate and the crystal nucleus preferential growth direction are regulated and controlled, the rapid feeding and curing technology is combined, the low supersaturation environment is constructed, the silver powder is induced to grow in the specific direction, and the twin crystal proportion is remarkably increased.

The invention discloses a high-activity short-cut nitrification quick-start long-term stable operation process, which relates to the technical field of biological sewage treatment, and comprises the following steps: inoculating sludge, carrying out anaerobic fermentation pretreatment, and removing expanded sludge and sludge foam in combination with quick sludge discharge and manual removal; controlling the number of days of sludge age, reproliferating the sludge, enriching ammonia oxidizing bacteria, and inhibiting and elutriating nitrite oxidizing bacteria; long-term operation is carried out under the condition of no sludge discharge, the abundance and activity of ammonia oxidizing bacteria are maintained, and meanwhile, the abundance of nitrite oxidizing bacteria is controlled; the proliferation of nitrite oxidizing bacteria is controlled by using the predation effect of protozoa and metazoan, and the accumulation rate of nitrite in the reactor is controlled; monitoring the dissolved oxygen, the pH value and the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the reactor in real time, and regulating and controlling the influent ammonia nitrogen load and the free ammonia concentration; dissolved oxygen distribution is adjusted in an intermittent aeration or microporous aeration mode, and the operation conditions of the short-cut nitrification reactor are optimized. The method is simple to operate, economical and effective.

The invention discloses a preparation method of a pyridine-nitrogen-rich copper monatomic catalyst and application of the pyridine-nitrogen-rich copper monatomic catalyst to ammonia production through electro-catalysis of nitrate reduction, the catalyst shows good catalytic performance of ammonia production through nitrate reduction in an alkaline medium, and theory and experiments prove that the copper monatomic catalyst with rich copper-pyridine nitrogen-carbon active sites has good catalytic performance. The adsorption energy of NO3 <-> and corresponding intermediates is improved, and the energy barrier of the rate control step is reduced, so that the process of reducing nitrate to prepare ammonia is promoted.

Molecular electrocatalytic systems for ammonia production from wastewater nitrate are described. The electrocatalytic systems use ammonia-selective homogeneous molecular NOsRR catalysts in real wastewater.

The invention provides a water quality multi-parameter detection method and system based on ultraviolet-visible light section spectroscopy, which are used for detecting turbidity, chemical oxygen demand and nitrate nitrogen concentration in a water sample. The method comprises the following steps: firstly, acquiring spectral data of a water sample, converting the spectral data into absorbance, then calculating influence factors of turbidity, chemical oxygen demand and nitrate nitrogen on a mixed sample spectrum, and dividing a spectral range into three characteristic spectral sections according to the influence factors, which correspond to the turbidity, the chemical oxygen demand and the nitrate nitrogen respectively. And finally, establishing a multi-parameter detection model by using a partial least squares PLS method for predicting turbidity, chemical oxygen demand and nitrate nitrogen concentration. According to the method, the interference of serious overlapping of multi-parameter spectral lines is avoided through segmented analysis of the spectrum, the detection precision is improved by utilizing a method of fusing the first-order derivative spectrum, and particularly, the effect in the aspect of nitrate nitrogen detection is remarkable. The method is easy and convenient to operate and low in cost, and a more effective technical means is provided for water quality monitoring and water environment protection.

A process produces unsubstituted or at least singly substituted cycloalkanones by electrochemical oxidation of unsubstituted or at least singly substituted, saturated cycloaliphatic hydrocarbons in the presence of an inorganic or organic nitrate salt in an electrolysis cell in a reaction medium in the presence of oxygen.

A process produces unsubstituted or at least monosubstituted α,ω-dicarboxylic acids and ketocarboxylic acids by electrochemical oxidation of unsubstituted or at least monosubstituted, monounsaturated or polyunsaturated cycloalkenes by electrochemical oxidation in the presence of an inorganic or organic nitrate salt in an electrolysis cell in a reaction medium in the presence of oxygen.

The invention provides a method for recovering waste etching liquid containing phosphoric acid, acetic acid and nitric acid, which comprises the following steps: carrying out reduced pressure distillation on the waste etching liquid under a reduced pressure condition, distilling and condensing light components of nitric acid and acetic acid to obtain mixed acid liquor of acetic acid and nitric acid, and detecting the content of nitric acid, acetic acid and water in the mixed acid liquor; adding sodium hydroxide or potassium hydroxide and the like into mixed acid liquor of acetic acid and nitric acid, so that all nitric acid in the mixed acid liquor generates nitrate; and adding acetic anhydride into the acetic acid-containing mixed solution, fully reacting, filtering the separated salt, adding an extracting agent into the filtrate, and collecting the high-purity acetic acid. According to the method, phosphoric acid, acetic acid and nitrate in the waste etching liquid are recycled, the recycled acetic acid is high in purity, high in recycling rate and high in operability, large-scale production can be met, resource recycling is achieved to the maximum extent, direct emission of non-phosphorus resources of the waste etching liquid is avoided, and resource waste and environmental pollution are avoided.

The invention discloses a sulfur disproportionation-mediated low-temperature high-efficiency low-carbon denitrification and synchronous ammonium recovery method for sewage, belongs to the field of sewage treatment, and aims to solve the problems that an existing autotroph denitrification process cannot adapt to water quality fluctuation and seasonal variation and is poor in engineering applicability. Polyculture denitrification and elemental sulfur disproportionation (SD) are used as an effective enhanced denitrification scheme and are applied to a low-temperature SDAD system of actual sewage. Sulfide and polysulfide generated in situ through elemental sulfur disproportionation reaction and low-concentration sodium acetate under the polyculture condition are used as supplementary electron donors, so that the denitrification rate is remarkably increased. The process of reducing dissimilatory nitrate into ammonium (DNRA) in the SD-MixBNR system is beneficial to emission reduction of greenhouse gases while realizing ammonium recovery. According to the method, the SD-MixBNR system can be promoted to be widely applied to actual engineering projects under the carbon neutralization background, and the stability and adaptability of the SD-MixBNR system in the face of various water quality fluctuations and seasonal changes are enhanced.

The invention discloses an integrated oil phase emulsion explosive and a preparation method thereof. The emulsion explosive is prepared from the following raw materials: a water-phase component, an oil-phase component and an emulsifier for emulsifying the water-phase component and the oil-phase component, wherein the water-phase component contains a modified oxidant formed by loading a nitrate oxidant component on p-aminophenyl POSS (Polyhedral Oligomeric Silsesquioxane); the preparation process of the modified oxidizing agent comprises the following steps: A, fully dispersing a nitrate oxidizing agent component and p-aminophenyl POSS in an aqueous solution, so that the nitrate oxidizing agent component is fully attached to the p-aminophenyl POSS; and B, separating a solid-phase component, namely the modified oxidant, from the solution system obtained in the step B. According to the integrated oil phase emulsion explosive and the preparation method thereof provided by the invention, the sensitivity and the power can be well considered.

The invention relates to the technical field of catalysts, in particular to a catalyst for fire coal and a preparation process thereof, and the catalyst comprises the following materials in parts by weight: 2-8% of rare earth nitrate, 5-18% of alkaline earth metal salt, 2-5% of alkali metal salt, 0.5-1% of copper-manganese composite oxide, 0.2-1.5% of transition metal salt, 0.1-0.3% of nonionic surfactant, 0.05-0.15% of organosilicon compound and the balance of water. The coal-fired catalyst is specially designed for a power plant, has excellent permeation and adsorption performance, solves the problem that the coal-fired catalyst is difficult to uniformly disperse in blocky coal, promotes full combustion of the coal in the power plant, improves the combustion rate and the burn-off rate, eliminates solid hazardous wastes from the preparation raw materials, ensures safety and environmental protection, and is suitable for industrial production. The power plant can be assisted to save coal resources, emission of harmful pollutants can be reduced from the source, and remarkable economic benefits and environmental benefits are brought to the power plant.

The invention relates to a vertical flow enhanced biological denitrification device and a sewage treatment method, a denitrification agent adding assembly is additionally arranged at a proper position of an existing vertical flow reaction device, namely the outer side of an outer inclined flow guide part, a corresponding enhanced denitrification agent can be added at a selected point position, a denitrification reaction is further enhanced, and the denitrification effect is improved. The selective reaction of the functional microorganism reaction is improved, nitrate generated by the anaerobic ammonia oxidation reaction is consumed, and a sufficient matrix is provided for anaerobic ammonia oxidation, so that the anaerobic ammonia oxidation reaction is greatly promoted, and the total nitrogen removal rate is further improved; by accurately controlling the dosing position and accurately dosing according to the reaction, the nitrogen removal efficiency of the autotroph is enhanced, the coordination of the minimization of the dosing amount of the medicament and the maximization of the nitrogen removal efficiency is realized, and finally, the green, low-carbon, economical and efficient nitrogen removal target of the sewage is achieved.

The invention discloses a device for recovering ammonium sulfate through electrocatalytic reduction and a using method thereof.The device comprises a wastewater pool and an outer shell, a physical filtering bin is fixedly installed in the outer shell, a water inlet of the physical filtering bin is communicated with the wastewater pool, and a water outlet of the physical filtering bin is fixedly connected with a closed electrolytic tank; the upper end of the closed electrolytic tank is fixedly connected with an electrochemical workstation, the lower end surface of the closed electrolytic tank is fixedly provided with a lead-out port, the lead-out port is fixedly connected with a product recovery device, the product recovery device comprises a first chamber and a second chamber, and a gas diffusion port is formed between the first chamber and the second chamber; a gas diffusion film is fixedly installed in the gas diffusion opening, a product discharging opening is fixedly formed in the second cavity, a product discharging valve is fixedly installed at the product discharging opening, and the nitrate reduction device is simple in structure and convenient to use, and the nitrate reduction efficiency is greatly improved.

The invention discloses fluoride-salt-free and nitrate-free medium-temperature semitransparent glaze for steel plate enamel as well as a preparation method and application of the medium-temperature semitransparent glaze, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, potassium feldspar, anhydrous borax, sodium carbonate, titanium dioxide, monopotassium phosphate and zinc oxide according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 800-840 DEG C and the firing time of 20-30 minutes, and is suitable for a steel plate. The method can be used for producing green and environment-friendly enamel products.

The invention discloses fluoride-salt-free and nitrate-free high-temperature acid-resistant translucent glaze for steel plate enamel as well as a preparation method and application of the translucent glaze, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, anhydrous borax, titanium dioxide, trisodium phosphate, potassium carbonate, lithium carbonate, aluminum oxide, zinc oxide and sodium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 840-880 DEG C and the firing time of 820-830 minutes, and is suitable for a steel plate. The method can be used for producing green and environment-friendly enamel products.

The invention discloses a mixed nitrate type molten salt preparation device, and belongs to the technical field of nitrate production, and the mixed nitrate type molten salt preparation device comprises a shell; a rotating shaft is arranged in the shell, a lantern ring is arranged on the periphery of the rotating shaft, a fixing rod is arranged on the periphery of the lantern ring, a scraping plate is fixedly arranged at the end, away from the lantern ring, of the fixing rod, and a transmission assembly is arranged in the center of the shell. The inner wall of the shell is scraped back and forth through rotation of a scraper, so that the situation that after crystals exist on the shell, cleaning is not conducted in time, and consequently the follow-up fused salt raw material mixing work is affected is avoided, manual cleaning operation on the inner wall of the shell is reduced, and the working efficiency is improved. And the scraping plate generates a vibration effect through the elastic reset effect of the arc-shaped elastic plate, so that when the scraping plate is blocked by crystals, the crystals can be effectively shaken off through vibration.

The invention provides a self-supporting carbon-based material loaded with iron nanoparticles as well as a preparation method and application of the self-supporting carbon-based material, and belongs to the technical field of preparation and application of an electrocatalyst for removing nitrate in sewage. The preparation method of the self-supporting carbon-based material loaded with the iron nanoparticles comprises the following steps: providing a carbon felt subjected to acid pickling and water bath heating; the method comprises the following steps: mixing an iron precursor and urea in a solvent to obtain a mixed solution containing iron salt; and mixing the carbon felt with the mixed solution containing the iron salt, and carrying out a hydrothermal reaction to obtain the self-supporting carbon-based material loaded with the iron nanoparticles. When the iron nanoparticle-loaded self-supporting carbon-based material provided by the invention is used as a cathode for electro-catalysis of nitrate-containing wastewater, a good removal rate and ammonia nitrogen selectivity are achieved, and the catalyst can keep relatively high nitrate nitrogen removal and ammonia nitrogen production effects under the conditions of acidity, neutrality, alkalinity and different initial nitrate concentrations; the method has the advantages of high removal efficiency, good ammonia nitrogen selectivity, strong stability and the like.

The invention provides a catalyst for preparing phenol through catalytic hydrogenation of guaiacol as well as a preparation method and application of the catalyst. The preparation method of the catalyst comprises the following steps: fully dissolving magnesium nitrate, P123 and urea in deionized water, carrying out hydrothermal reaction, filtering, washing, drying and roasting to obtain an MgO carrier; immersing the MgO carrier in an alkali metal nitrate aqueous solution, drying and roasting to obtain an alkali metal element loaded MgO carrier; the alkali metal is selected from one of Li, Na, K or Cs; and immersing the alkali metal element loaded MgO carrier in a methanol solution of chloroplatinic acid, removing methanol, drying, and then carrying out reduction treatment to obtain the catalyst. The catalyst disclosed by the invention is applied to catalytic hydrodeoxygenation of guaiacol and shows excellent catalytic performance, the hydrodeoxygenation reaction conditions are mild, and the target product phenol can be obtained with high selectivity and high yield.

The invention discloses a self-gas-stirring partition plate type efficient anaerobic bioreactor and a method, and belongs to the field of nitrogen and sulfur-containing organic wastewater biological treatment devices. The reactor sequentially comprises a first reaction zone, a second reaction zone, a third reaction zone and a three-phase separation zone which are communicated with one another from bottom to top. Anaerobic granular sludge is inoculated in the first reaction zone for hydrolytic acidification reaction; anaerobic activated sludge with denitrification and sulfate reduction functions is inoculated in the second reaction area, and nitrate and sulfate reduction reaction is carried out. Anaerobic activated sludge with a methanogenesis function is inoculated in the third reaction area, and a methanogenesis reaction is carried out. The three reaction zones are separated by ecological partition plates to ensure water and air permeability and no mud permeability. According to the reactor, the ecological partition plates are arranged to realize anaerobic reaction function division, and multiple components in complex organic wastewater are synergistically removed, so that the pollutant removal efficiency is improved; the flow state in the reactor is improved through self-produced gas backflow, the mass transfer and detoxification effects are enhanced, and the decontamination effect and stability of the reactor are improved.