1159 results about "Nitrate salts" patented technology

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.

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 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 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 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 Fe / C loaded membrane module, a PN / A-MABR autotrophic nitrogen removal device, a preparation method and a sewage treatment method, and belongs to the technical field of sewage treatment. According to the invention, the problem that the treatment effect is influenced by NO3 <->-N accumulation in the existing membrane aeration coupling partial nitrification-anaerobic ammonia oxidation process is solved. Comprising a frame and a membrane body attached to the outer portion of the frame, the membrane body comprises a hydrophobic organic membrane layer, an iron-carbon material layer and a biological membrane layer which are sequentially arranged, and the hydrophobic organic membrane layer is attached to the outer portion of the frame. The iron-carbon material is added between the hydrophobic organic membrane layer and the biological membrane layer, the iron-carbon micro-electrolysis process is coupled with the dissimilatory process of nitrate generated by microbial metabolism, the removal of NO3 <->-N generated by anaerobic ammonia oxidation is enhanced, and the total nitrogen removal efficiency is improved.

The invention discloses fluoride salt-free and nitrate-free low-temperature matte glaze for steel plate enamel as well as a preparation method and application of the low-temperature matte glaze, and belongs to the technical field of enamel. The matte glaze is prepared from quartz, borax pentahydrate, sodium carbonate, titanium dioxide, magnesium oxide, monopotassium phosphate, calcium carbonate, zinc oxide, magnesium carbonate, lithium carbonate, aluminum oxide and zirconium silicate according to a specific mass ratio. The preparation method comprises the following steps: mixing the raw materials, melting at 1300 + / -10 DEG C in a pure oxygen environment, and quenching after wiredrawing to detect a molten state. The matte glaze completely avoids the use of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are eliminated from the source, the fluorine content of the product is not detected through detection, and the limit value requirements of European Union REACH regulations are met. Zinc oxide and ZnO / TiO2 are added, so that the liquid phase viscosity is reduced, ion diffusion is accelerated, and the opacity (opacification performance) and gloss of the porcelain glaze are enhanced.

The invention discloses a fluoride-salt-free and nitrate-free cast iron enamel zirconium white glaze as well as a preparation method and application thereof, and belongs to the technical field of enamel. The zirconium white glaze is prepared from quartz, borax pentahydrate, magnesium carbonate, potassium carbonate, potassium feldspar, zinc oxide, aluminum hydroxide, calcium carbonate, zirconium silicate, sodium tripolyphosphate and lithium 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 zirconium white 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, and meanwhile, the zirconium white glaze has good porcelain surface, luster and firing adaptability, is suitable for cast iron matrixes, has the firing temperature of 740-760 DEG C and the firing time of 87-87 hours, and can be widely applied to cast iron substrates. The method can be used for producing green and environment-friendly enamel products.

The invention relates to the technical field of nitrate production, in particular to a potassium nitrate purification device which comprises a dissolving tank, a filtering device, a crystallization kettle, a centrifugal machine and a drying machine with a steam jacket which are sequentially connected in series through pipelines. The dissolving tank first jacket is connected with a heat source through a circulating pipeline; a liquid outlet of the centrifugal machine is sequentially connected with the cyclone separator, the ceramic membrane filter, the cationic resin column, the first temporary storage tank and the heat source, and the first heat exchanger and the second heat exchanger are sequentially installed between the first temporary storage tank and a heating medium inlet of the heat source. A steam outlet pipeline of the steam jacket is connected with a heat medium inlet of the first heat exchanger, the first heat exchanger is connected with the second temporary storage tank through a pipeline, and the second temporary storage tank is connected with the heat source through a pipeline. A pipeline of the second vacuum unit is connected with a thermal medium inlet of a second heat exchanger, and the second heat exchanger is connected with a second temporary storage tank. According to the method, the potassium nitrate purification efficiency, the product purity, the resource utilization rate and the energy economy are synergistically improved.

The invention discloses fluoride-salt-free and nitrate-free low-temperature pearlescent glaze for steel plate enamel as well as a preparation method and application of the pearlescent glaze, and belongs to the technical field of enamel. The pearlescent glaze is prepared from quartz, anhydrous borax, titanium dioxide, magnesium carbonate, sodium tripolyphosphate, potassium carbonate, lithium carbonate, potassium feldspar, zinc oxide and V-26 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 pearlescent 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 pearlescent glaze has good porcelain surface, luster and low-temperature firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 760-800 DEG C and the firing time of 10-20 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 CuCo / CoOx catalyst for electrocatalytic nitrate reduction synthesis of ammonia and a preparation method of the CuCo / CoOx catalyst. According to the method, cobalt salt, copper salt and alkali serve as raw materials, an amorphous CoOx layer rich in defects grows on a CuCo alloy substrate in situ through the step of combining hydro-thermal synthesis and low-temperature reduction heat treatment, and therefore the CuCo / CoOx composite catalyst is prepared. The key point of the invention lies in that the interface structure and electronic characteristics of the catalyst can be effectively regulated and controlled by accurately regulating and controlling the time of reduction heat treatment, so that the catalytic performance of the catalyst is optimized. When the prepared catalyst is applied to electrocatalytic nitrate reduction synthesis ammonia reaction, the catalyst shows excellent activity and selectivity in an alkaline medium; under the potential of-0.7 V vs.RHE, the Faraday efficiency of ammonia synthesis can reach 99% or above, and the ammonia yield reaches up to 21.2 mg.h <-1 >. Mg-1. The method provided by the invention has the advantages of simple process, low cost, good controllability and the like, and has important application value in the fields of nitrate wastewater resource utilization and electrochemical green ammonia synthesis.

The invention discloses fluoride-salt-free and nitrate-free low-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 low-temperature firing adaptability, and is suitable for steel plate substrates, the firing temperature is 760-800 DEG C, and the firing time is 2-3 hours. The method can be used for producing green and environment-friendly enamel products.

The invention discloses a compatible molybdenum-aluminum mixed acid etching solution which comprises the following components in percentage by mass: 4%-7% of nitric acid, 55%-65% of phosphoric acid, 17%-28% of acetic acid, 0.5%-3% of an oxidizing additive, 0.05%-5% of a metal corrosion inhibitor and 10%-20% of deionized water, and the oxidizing additive is ceric nitrate and at least one selected from sodium nitrate, potassium nitrate and ammonium nitrate; the etching liquid does not contain other organic components except for organic carboxylic acid and organic carboxylate. According to the compatible molybdenum-aluminum mixed acid etching solution, on the basis that ceric nitrate is introduced, the content of nitric acid is reduced, the nitrate ion concentration is increased by adding nitrate, the overall oxidation performance of an etching solution system is improved, the etching rate ratio of different metals is adjusted, CD-Bias is reduced, the etching dip angles of a molybdenum single layer and a molybdenum-aluminum laminated layer are controlled to be kept at 20-50 degrees, and the problem of aluminum thorns is solved. The invention further discloses a molybdenum-aluminum etching method based on the compatible molybdenum-aluminum mixed acid etching solution.

A composite material for passive cooling includes a porous structure including an expanded graphite and a surfactant, the porous structure being provided with at least one crystalline deliquescent salt that is selected from the group consisting of chloride, bromide, sulphate, and nitrate. The uses of the composite material in passive cooling are also addressed.

The invention provides an anti-ionizing radiation fiber with high filling amount, high strength and high elasticity and a preparation method and application thereof, and belongs to the field of functional fiber materials.The preparation method comprises the steps that rare earth nitrate and citric acid are dissolved in an acidic alcohol aqueous solution, heated and stirred, the pH value is adjusted, sol is obtained, the sol is subjected to secondary heating treatment to obtain gel, and the gel is dried to obtain the high-filling-amount high-strength high-elasticity anti-ionizing radiation fiber. Aging, drying, grinding and calcining the gel to obtain rare earth composite powder; wherein the rare earth nitrate is a mixture of gadolinium nitrate, dysprosium nitrate and cerium nitrate; adding polyurethane into a mixed solution of DMF and xylene, stirring, adding the rare earth composite powder, stirring, and defoaming to obtain a spinning solution; preparing nascent fibers from the spinning solution through wet spinning; and drawing, washing and drying to obtain the anti-ionizing radiation fiber. The anti-ionizing radiation fiber prepared by the invention has excellent shielding property, mechanical property and air permeability.

The invention discloses a fused salt phase change heat storage composition as well as a preparation method and application thereof, and belongs to the technical field of heat storage. The fused salt phase change heat storage composition provided by the invention comprises the following components: a fused salt material, the melting point of the fused salt material is 100-1500 DEG C, and the absorption coefficient of the fused salt material to infrared waves is 0-100m <-1 >; the infrared absorbing material comprises at least one of transition metal chlorine salt, metal carbonate, metal sulfate, metal nitrate, a carbon-based material, silicon carbide and spinel. The fused salt phase change heat storage composition provided by the invention has high heat exchange power (average heat release power) and heat storage energy density. The invention further provides a preparation method and application of the fused salt phase change heat storage composition.

The invention relates to the technical field of water treatment, and discloses a sludge quality-divided reflux type aerobic-anoxic sulfur autotrophic activated sludge denitrification process. The process comprises the following steps: wastewater enters a sectional type aerobic tank, the wastewater enters the sectional type aerobic tank, organic matters are removed in a strengthened manner in a first section of aerobic tank, part of ammonia nitrogen is converted into nitrite nitrogen and nitrate nitrogen, and nitrification is strengthened in a second section of aerobic tank, so that the ammonia nitrogen is deeply removed; effluent of the sectional type aerobic tank enters an anoxic tank and is completely mixed with sulfur particles and activated sludge for sulfur autotrophic denitrification; effluent of the anoxic tank enters a secondary sedimentation tank for sedimentation, supernate is discharged, and bottom mud enters a hydrocyclone to be divided into heavy sludge and light sludge; the heavy sludge flows back to the front end of the anoxic tank, the light sludge flows back to the front end of the sectional aerobic tank, and the remaining sludge is discharged. According to the invention, sulfur autotrophic denitrification is deeply integrated into an activated sludge system, so that high-efficiency nitrogen removal without carbon source and internal reflux is realized.

The invention relates to the field of glass, in particular to lithium-free alkali aluminosilicate glass as well as a preparation method and application thereof. According to the glass, SiO2, Al2O3, Na2O, K2O, MgO and ZrO2 serve as main components, the content of Li2O is lower than 100 ppm, a nitrate-sulfate-carbon powder composite clarifying agent is adopted, the number of bubbles and the content of residual sulfur are effectively reduced, and use of a toxic or ultraviolet absorption type clarifying agent is avoided. ZrO2 is obtained by calcining a zirconium-based metal-organic framework material and is good in dispersity, and the devitrification resistance is improved. During float forming, through micro-positive pressure, high-purity protective atmosphere and four-zone gradient temperature control, the tin penetration depth is controlled within 15 microns, and the surface tin content is smaller than or equal to 4 micrograms / cm < 2 >. The obtained glass has high light transmittance, high hardness and excellent chemical strengthening performance, and is suitable for the high-end fields of electronic display cover plates, vehicle-mounted screens, touch panels, photovoltaic substrates and the like.

The invention discloses a preparation method of a controllable Co-Cu bimetallic oxide nano-catalyst, and the controllable Co-Cu bimetallic oxide nano-catalyst is applied to electro-catalysis, so that low-concentration nitrate pollutants in high-salinity wastewater can be efficiently removed. According to the preparation method, a constant-voltage electrodeposition method is utilized, the atomic-scale dispersed Co-Cu double-active-site catalyst is constructed on a foamed nickel substrate, and the prepared bimetallic Co-Cu active-site catalyst can remove low-concentration nitrate pollutants efficiently and highly selectively and is suitable for purification of nitrate wastewater with a wide pH range and different concentrations. The method is easy to operate, high in stability and good in electrocatalytic activity, and a reliable solution with practical application potential is provided for green low-carbon electrocatalytic purification of high-salt nitrate wastewater.

The pure membrane MBBR sewage treatment system comprises an anoxic denitrification zone, an anaerobic ammonia oxidation zone, an aerobic oxidation zone, a high-density sedimentation zone, an MBBR biological filtration zone, a backwashing water tank and an equipment room, the anoxic denitrification region is used for carrying out amination reaction, organic matter hydrolysis reaction and denitrification reaction on the sewage and nitrate and nitrite in the anoxic denitrification region; the anaerobic ammonia oxidation zone is used for reacting the sewage with nitrite to generate nitrogen; the aerobic oxidation zone is used for promoting microorganisms to degrade organic matters in sewage and convert ammonia nitrogen; the high-density settling zone is used for separating muddy water in sewage; the MBBR biological filtration area is used for filtering suspended matters in the sewage; the backwashing water tank is used for providing backwashing make-up water for the MBBR biological filtration area; and the equipment room is used for placing disinfection equipment, a fan and a power distribution control system.

The invention discloses a high-entropy perovskite oxide, a preparation method thereof and application of the high-entropy perovskite oxide as an electrocatalyst, and belongs to the technical field of high-entropy transition metal oxides. A sol-gel method is adopted, various metal nitrates and lanthanum nitrate are dissolved in water and ethylene glycol in an equimolar mode, and an ammonium citrate complexing agent is added. And then heating at 120 DEG C for 10 hours. And heating the obtained gel precursor to 600 DEG C in a muffle furnace at a heating rate of 10 DEG C / min, maintaining the temperature for 2 hours, and cooling to obtain the high-entropy perovskite oxide LaBxO3. The high-entropy perovskite oxide electrocatalyst which is simple in synthesis method, stable in structure and easy in raw material obtaining is obtained, and the electrocatalyst can be applied to electrocatalytic nitrate radical reduction and sulfur ion oxidation; and a foundation is laid for developing other high-entropy transition metal oxides as electrocatalysts for synthesizing value-added chemicals by electrocatalyzing nitrate radicals and sulfur-containing wastewater.

The invention discloses a sea-land interaction zone underground water pollution source tracing method based on multi-pollutant fingerprints, and the method comprises the steps: constructing a fingerprint feature library of eight key pollutants including cadmium, arsenic, nitrate nitrogen, ammonium nitrogen, phosphate, total petroleum hydrocarbon, sulfamethoxazole, pH value and the like; statistical characteristic models of four pollution sources of industrial emission, agricultural non-point sources, oil exploitation and aquaculture are established, Z-Score standardization and a similarity calculation method based on a standard normal distribution probability density function are adopted, comprehensive similarity evaluation is performed in combination with a risk weight distribution mechanism, a similarity threshold value of 0.7 is set to perform pollution source identification and sorting, and the pollution sources are identified and sorted according to the similarity threshold value. And correction is performed by considering environmental factors such as tide, season and geology of a sea-land interaction zone. The method can quickly and accurately recognize the groundwater pollution source of the sea-land interaction zone, the traceability accuracy rate reaches 80% or above, and scientific and technical support is provided for prevention and control of groundwater pollution of the sea-land interaction zone and formulation of an environmental protection policy.

The application discloses a kind of microspheroidal high-entropy spinel type ferrite wave-absorbing materials and preparation method thereof, belong to electromagnetic wave absorbing material technical field, the preparation method includes with the designed molar ratio six metal nitrate is weighed and dissolved in deionized water, then add ammonium fluoride, urea, after stirring, the obtained solution is hydrothermal reaction at a certain temperature for a certain time to obtain precursor, the precursor is calcined to obtain microspheroidal high-entropy spinel type ferrite.The obtained wave-absorbing material is single-phase spinel structure, micron-sized spherical morphology, its chemical formula is MFe2O4;Wherein M=Co, Ni, Cu, Zn, Cr.The microspheroidal high-entropy spinel type ferrite wave-absorbing material and preparation method thereof are used, and the performance of pure ferrite wave-absorbing material can be effectively improved, with the characteristics of simple preparation, strong absorption performance, absorption frequency bandwidth.

This invention discloses a silver-cobalt composite oxide catalyst, its preparation method, and its application in the electrocatalytic reduction of nitrate to ammonia, relating to the field of electrochemical catalyst technology. The invention involves dissolving silver nitrate and cobalt nitrate hexahydrate in deionized water, stirring until completely dissolved, adding citric acid as a complexing agent, and continuing stirring to form a homogeneous and stable metal complex solution. The metal complex solution is continuously stirred under heating conditions to allow the solvent in the system to gradually evaporate, forming a viscous gel, which is then dried to obtain a catalyst precursor. The catalyst precursor is ground and placed in a high-temperature furnace for programmed temperature calcination in air, followed by cooling to room temperature to obtain the target catalyst. The preparation method of this invention is simple and controllable, with abundant and inexpensive raw materials, requiring no complex equipment or harsh reaction conditions, and is easy to scale up for industrial production. The obtained catalyst exhibits extremely high catalytic activity and selectivity for the electrocatalytic reduction of nitrate to ammonia, with a high ammonia yield.

The invention discloses a method for realizing deep autotrophic nitrogen removal of sludge digestion liquid based on alternate intermittent aeration of a double-membrane aeration bio-membrane reactor (MABR). The process device comprises a sludge digestion liquid raw water tank, a single-stage double-MABR reactor, two MABR devices and a water outlet tank. According to the method, sludge digestion liquid enters the single-stage double-MABR reactor, the two MABR devices are alternately and intermittently aerated, the state of one aeration and one aeration stopping is always kept, and ammonia nitrogen in raw water is converted into nitrite through ammonia oxidizing bacteria enriched on the inner side of an MABR membrane. And simultaneously supplying to anaerobic ammonium oxidation bacteria enriched on the outer sides of the two MABR membranes through matrix diffusion for denitrification and generation of nitrate. Denitrifying bacteria enriched on the outer side of the MABR membrane utilize raw water organic matters to drive short-cut denitrification to synchronously supply nitrite to anaerobic ammonium oxidation bacteria so as to realize deep autotrophic nitrogen removal. According to the invention, a double-anaerobic ammonia oxidation reaction hot area is constructed through alternate intermittent aeration of double MABRs, and efficient deep autotrophic nitrogen removal of the sludge digestion liquid can be stably realized.

The utility model relates to the technical field of wastewater treatment, in particular to a sulfur autotrophic denitrification filter tank device driven by a suspended packed bed. The sulfur autotrophic denitrification filter tank device comprises a regulating tank, a sulfur autotrophic denitrification biological filter tank and a sedimentation tank which are communicated in sequence; the adjusting tank is used for homogenizing the wastewater; a suspended sulfur autotrophic denitrification biological filler is arranged in the sulfur autotrophic denitrification biological filter, and the sulfur autotrophic denitrification biological filter is used for performing a sulfur autotrophic denitrification reaction to remove nitrate nitrogen in the wastewater; the sulfur autotrophic denitrification biofilter is also connected with a sulfur autotrophic denitrification dosing tank; the settling pond is used for standing and settling the wastewater; a water outlet for discharging treated wastewater is formed in the top of the sedimentation tank. According to the utility model, the suspended biological filler is combined with the sulfur autotrophic denitrification reagent, and the suspended sulfur autotrophic denitrification biological filler is arranged in the sulfur autotrophic denitrification biological filter, so that the mass transfer efficiency can be improved, and the deep removal of nitrate nitrogen in wastewater is realized.

Methods and systems of PFAS destruction in water containing nitrate. The methods and systems include filtering water containing PFAS and nitrate through a membrane selective for PFAS to obtain a membrane reject containing PFAS and nitrate and a filtrate containing nitrate, forming a treatment solution using the membrane reject including diluting the membrane reject and combining the membrane reject with a photosensitizer, a sulfite salt, and a sufficient amount of base such that the treatment solution has a pH of about 10 or more, and irradiating the treatment solution with UV light in a photoreactor to destroy a portion of the PFAS. Before dilution, a concentration of PFAS in the membrane reject may be between about 3 times and about 20 times greater than before the filtering step. Dilution of the membrane reject may include between about a 3 and about a 20 times dilution.

The invention discloses a non-aqua regia gold extraction agent and method for recovering precious metal from waste containing precious metal. The non-aqua regia gold extraction agent is composed of nitrate, metal chloride and weak acid, by precisely regulating and controlling the concentrations of nitrate, chloride ions and hydrogen ions in the non-aqua regia gold extraction agent, the precious metal in the waste containing the precious metal can be subjected to green, efficient and selective oxidation leaching under the normal temperature condition, the precious metal ions in the leaching solution are subjected to reduction operation, and therefore the recovery rate of the precious metal in the waste containing the precious metal is improved. And a pure noble metal product can be obtained. Compared with a traditional aqua regia method, the method has the advantages that strong acid reagents such as concentrated nitric acid and concentrated hydrochloric acid are not used, corrosion to equipment and operation risks are remarkably reduced, and secondary emission of harmful gas is avoided. The method has the remarkable advantages of being environmentally friendly, easy and convenient to operate, mild in reaction condition, low in equipment requirement, high in leaching rate and the like, is suitable for large-scale and industrial production, and has wide application prospects and commercial value in the field of precious metal recovery.

The invention discloses a bottom mud ecological restoration material as well as a preparation method and application thereof. The material is composed of a degradable carrier, a treatment flora and a multifunctional filler. The carrier is porous particles die-cast by corn straws and the like; the treatment flora comprises photosynthetic bacteria, bacillus and nitrifying bacteria; the filler is prepared from non-nitrate type hydrotalcite-like compounds, calcium nitrate, nitrate type hydrotalcite-like compounds and a flocculating agent according to a specific mass ratio. The preparation method comprises the following steps: carrying out pressure casting on the carrier, adsorbing the flora, and rolling the filler to form balls. The restoration method comprises the steps that a river channel is cut off in the dry season to form a closed area, materials are put according to the area ratio of 10: 1 for preliminary restoration, and after standing is conducted for 1-5 days, the materials are put along with water flow according to the area ratio of 2: 1 for deep restoration. Through the physical, chemical and biological synergistic effect, the sediment redox environment can be effectively improved, pollutant release and degradation are promoted, operation is easy and convenient, and the risk of secondary pollution is low.