126 results about "Potassium dichromate" patented technology

The invention relates to the technical field of multi-water quality analysis, in particular to a full-automatic water quality COD analysis method and device.The method comprises the steps that an absorbance spectrogram and electrochemical characteristics of a target water sample in a first preset wave band are obtained, and an original signal set is generated; obtaining dynamic characteristics of fusion liquid of the target water sample and the potassium dichromate solution in a second preset wave band, and performing characteristic level fusion on the dynamic characteristics and the original signal set to generate a reaction characteristic set; manifold learning and feature optimization processing are carried out on the reaction feature set, and an optimized feature set is generated; performing hybrid neural network modeling processing according to the optimized feature set, and outputting a preliminary COD predicted value; and after the preliminary COD predicted value is corrected, a correction result is verified, and a COD analysis set is generated. According to the invention, multi-source signal data can be efficiently integrated and deeply optimized, and the defects of low analysis efficiency and accuracy caused by insufficient data processing capability in complex water sample analysis in the prior art are overcome.

The invention relates to the field of aerospace, and discloses a method for evaluating the adhesive property of an aviation fiber metal laminate, which comprises the following steps of: completely overlapping unidirectional carbon fiber prepreg until the thickness is consistent with that of a metal plate; the metal plates are grouped, and the metal surfaces are treated through a conventional treatment method, a silane coupling agent treatment method and a potassium dichromate treatment method; bonding and curing the treated metal plate and the carbon fiber test piece by adopting epoxy resin and a modified adhesive in a crossing manner, then bonding a metal gasket to obtain a single-lap-joint test piece, testing, recording the change of a strain field in a bonding area in real time, and performing quantitative calculation. According to the method, improvement of the bonding performance of the aviation fiber metal laminate by different methods is quantified from data, a basis is provided for more accurate quantitative analysis, and performance evaluation in the material research and development process is more accurate.

The invention relates to a straw and willow product dyeing sewage treatment device, aiming to solve the technical problems that potassium dichromate is often used as an oxidant and a mordant in the current printing and dyeing process, a large amount of chromium is also consumed in the preparation of a printing roller, and the efficiency of sewage treatment only through physical filtration and other steps is low, and particulate matter, suspended matter and heavy metal ions in the sewage cannot be efficiently treated. The device comprises a shell and a dosing drum shaft rotatably arranged on the top of the shell, a plurality of groups of electrostatic adsorption components connected to an external electrostatic generator are arranged in an annular array on the outer edge surface of the dosing drum shaft, a group of the electrostatic adsorption components forms a disc-shaped structure, and a plurality of groups of the electrostatic adsorption components are connected to the dosing drum shaft. The device adsorbs impurities, suspended matter and heavy metal ions in sewage through the electrostatic adsorption phenomenon, completes the efficient cleaning of impurities in sewage, and can efficiently complete the treatment of particulate matter, suspended matter and heavy metal ions in sewage.

The invention belongs to the technical field of crystal defect testing, and particularly relates to an FPD testing method for a monocrystalline silicon wafer micro-viewpoint defect, which comprises the following steps: accurately cutting off the head and the tail of a silicon rod to eliminate an end defect, and preparing a pure substrate by adopting an A-surface machine grinding / B-surface maintaining asymmetric treatment and segmented cleaning process; after pretreatment with a specifically proportioned corrosive liquid, carrying out temperature-controlled etching by using potassium dichromate-hydrofluoric acid to form a characteristic V-shaped pattern on the surface, and realizing visual identification by corresponding different defects to different patterns; gridding detection points are designed based on stress distribution, laser positioning coordinate mapping is performed, an imaging-correction-noise reduction-segmentation-intelligent classification algorithm chain is constructed to realize full-automatic detection, and a detection-analysis-optimization full-process data driving quality control system is established through visual data such as a thermodynamic diagram and a type matrix. And large-scale production of semiconductor silicon wafers is supported.

The invention provides a beneficiation method for low-grade fluorite ore containing magnesium carbonate, and belongs to the technical field of fluorite beneficiation. According to the method, the fluorite raw ore is subjected to classification and waste pre-discarding treatment, and pre-enriched minerals are obtained; the pre-enriched minerals are subjected to ore grinding treatment, and first ore pulp is prepared after water is added; carrying out flotation operation on the first ore pulp by adopting a flotation reagent; the flotation reagent comprises a compound inhibitor and a compound regulator, the compound inhibitor comprises aluminum sulfate, sodium hexametaphosphate, tannic acid, citric acid and sodium alginate, and the compound regulator comprises calcium lignosulphonate, hydroxyethyl cellulose and potassium dichromate. Through the mode, the beneficiation method for the magnesium-containing carbonate type low-grade fluorite ore can utilize the synergistic effect between the specific beneficiation technological process and the improved reagent system, acid leaching operation is omitted, meanwhile, the recovery rate and grade of fluorite are improved through the simpler process and the lower reagent cost, and the beneficiation efficiency is improved. And the method has an extremely high industrial application prospect.

The invention discloses an aperture testing method of a hard carbon negative electrode material and application thereof. The testing method comprises the following steps: preparing an alkaline caramel stock solution from glucose; preparing a potassium dichromate standard solution; identifying a caramel solution; making a caramel solution concentration-absorbance standard curve; the method comprises the following steps: heating and mixing m0g of a hard carbon sample and V0mL of a caramel solution with the concentration of C0g / L, centrifuging for the first time, taking supernate, centrifuging for the second time, absorbing V1 mL of supernate obtained after the second time of centrifugation, measuring absorbance A at the wavelength of 426nm, and calculating the mass m of residual caramel and the decolorization rate M of the caramel according to a formula I, a formula II and a formula III. The invention discloses an aperture testing method of a hard carbon negative electrode material and application of the aperture testing method, by adopting the testing method, the aperture of the hard carbon material can be tested, the mesopore development degree can be represented, the testing is simple and convenient, and the testing accuracy is high.

The present application belongs to the technical field of wastewater treatment, and discloses a method for treating electroplating wastewater by using bioreduction of biogas slurry and combined iron bio-oxidation, which is a secondary combined use technology for removing various heavy metals in electroplating wastewater by iron bio-oxidation, comprising the following steps: (1) collecting fermentation biogas slurry, and performing ultraviolet irradiation sterilization after aeration; (2) adding potassium dichromate solution and fresh nutrient solution to the sludge system, and culturing anaerobic sludge; (3) adding treated biogas slurry to the anaerobic sludge, and repeatedly domesticating chromium-reducing microorganisms; (4) configuring a mixed solution of comprehensive electroplating wastewater and biogas slurry according to a certain proportion; (5) building a primary treatment biological reactor, and reducing Cr(VI) in wastewater by anaerobic biological reduction under the promotion of pyrite; and (6) building a secondary biological reactor filled with straw biomass charcoal, and generating iron oxides under the action of functional bacteria to continue adsorbing Cd, Cu and Ni ions in wastewater.

The invention provides a method for measuring the water outlet rate of a hot-pressed iron block. The method is used for solving the problem that in the prior art, a method for measuring the water outlet rate of a hot-pressed iron block is not high in accuracy. The invention provides a method for measuring the water yield of a hot-pressed iron block, which comprises the following steps: (1) carrying out slag-iron separation treatment on the hot-pressed iron block to obtain a separated iron block and separated slag particles; (2) carrying out first iron content determination treatment on the separated iron block by using a direct-reading spectrometer to obtain the iron content of the separated iron block; carrying out second iron content determination treatment on the separated slag particles through a potassium dichromate titration method to obtain the iron content of the separated slag particles; according to the mass of the hot-pressed iron blocks, the mass of the separated iron blocks, the iron content of the separated iron blocks and the iron content of the separated slag particles, the water outlet rate of the hot-pressed iron blocks is obtained; the determination method is high in result accuracy, and the operation process is simple and easy to control.

Provided is a large specific surface area isomelanin-based carbon nanomaterial and a preparation method thereof. The preparation method of the isomelanin nanomaterial is to prepare a mixed solution of 1,8-dihydroxynaphthalene in acetone and water, and add a trichloride hexahydrate iron solution to the solution to form a 1,8-dihydroxynaphthalene-iron ion complex solution, then add a potassium dichromate solution to stir the reaction to obtain a black turbid solution, and centrifuge and wash to obtain the isomelanin nanomaterial; the isomelanin nanomaterial is subjected to high temperature heat treatment under an inert atmosphere, and KOH activation is performed to obtain an isomelanin nanomaterial with a large specific surface area. The preparation method of a supercapacitor electrode sheet is to mix the prepared carbon nanomaterial, carbon black and polytetrafluoroethylene, ultrasonically disperse them in an aqueous solution, dry them, roll them to obtain a black film, and press them on a current collector to obtain an electrode sheet. The isomelanin nanomaterial with a large specific surface area prepared by the method has high specific capacitance and cycle stability, and has broad applications in energy fields including supercapacitors.

The invention discloses a fluoride-salt-free and nitrate-free steel plate enamel high-temperature titanium creamy yellow cover glaze as well as a preparation method and application thereof, and belongs to the technical field of enamel. The cover glaze is prepared from quartz, anhydrous borax, rutile, potassium feldspar, trisodium phosphate, potassium carbonate, potassium dichromate and zinc oxide 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 overglaze completely avoids the use of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are solved from the source, the fluorine content of the product is not detected through detection, the product meets the European Union REACH regulation limit value requirements, and meanwhile, the overglaze has good hue, 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 has good application prospects. The method can be used for producing green and environment-friendly enamel products.

The invention relates to the technical field of slide processing. The invention discloses a slide treatment method for improving wall adhesion of 293T cells. The slide processing method comprises the following steps: preparing a cleaning solution; putting the slide into the cleaning solution, soaking, taking out the slide, washing the slide with deionized water, and putting the slide into a drying oven for drying; immersing the dried slide into PLL treatment liquid for 3-7 minutes, taking out and airing; wherein the cleaning solution is prepared from the following raw materials: potassium dichromate, water and concentrated sulfuric acid; the PLL treating fluid is poly-L-lysine with the mass concentration of 0.05%-0.15%, and the solvent is deionized water. The invention further discloses the slide prepared by the slide treatment method for improving the wall adhesion of the 293T cells. According to the slide treatment method, the adhesive force of the slide to 293T cells can be effectively improved, and the cell adherence is enhanced.

The application provides a method for detecting the titer of vitamin B12 in a fermentation liquor. The method comprises the following steps: preparing a potassium dichromate solution, a hydrochloric acid solution and a potassium dihydrogen phosphate solution, mixing the three solutions with the vitamin B12 fermentation liquor under certain conditions to generate cyanocobalamin, and then testing the titer of the cyanocobalamin by using a high performance liquid chromatography. The titer of the vitamin B12 detected by using the method is consistent with the titer detected by using a sodium cyanide method. The operation method greatly reduces the safety risk of an analyst caused by using the sodium cyanide, and the operation method is simple, easy to manage in a laboratory and can save the testing cost.

The present invention discloses a modification method for polyethylene suspension fillers used in a moving bed biofilm reactor. This method uses polyethylene fillers as the matrix. After treating the surface of the fillers with an acidic potassium dichromate mixed solution, it is immersed in an aqueous solution of a coupling agent (silane coupling agent KH-560, silane coupling agent KH-570, titanate coupling agent CS-311), and activated carbon powder and gelatin protein as modifiers are added, successfully loading activated carbon and gelatin protein onto the surface of the fillers. Based on conventional polyethylene fillers, after treating the surface with an acidic potassium dichromate mixed solution, the present invention utilizes the cross-linking reaction of the coupling agent with macromolecular compounds to make the surface of the fillers carry hydrophilic groups such as hydroxyl and carbonyl groups, providing favorable conditions for the rapid growth of microorganisms on the surface of the fillers and enhancing the film-forming effect of the fillers. During the sewage treatment process, it is superior to conventional fillers in terms of the film-forming speed of the fillers, the amount of biofilm, the tightness between the biofilm and the carrier, and the microbial activity, etc.

The invention belongs to the technical field of magnesium-aluminum magnesium alloy surface treatment, and particularly relates to a magnesium-aluminum alloy surface yellow ceramic film layer and a color control method thereof, and the method comprises the following steps: immersing a pretreated magnesium alloy into an electrolyte containing a coloring agent, and carrying out micro-arc oxidation to generate different yellow ceramic film layers on the surface of the magnesium-aluminum magnesium alloy; the coloring agent is one or two of potassium dichromate, potassium permanganate and anhydrous cupric sulfate; by adopting the method disclosed by the invention, uniform, smooth and compact ceramic film layers with different yellow colors can be generated on the surface of the magnesium-aluminum alloy. Six ceramic film layers with different yellow colors are prepared, the cost is low, the protection function and the decoration function can be achieved, and the requirements of different application scenes are met.

The invention discloses a method for measuring dissolved oxygen in aquaculture tail water by a spectrophotometric method based on an iodine-ascorbic acid-potassium dichromate system, and belongs to the technical field of water quality detection. The method comprises the following steps: sequentially adding a manganese sulfate solution and an alkaline potassium iodide solution into a to-be-detected culture tail water sample, sealing a container, fully reacting, and standing after the reaction is finished to completely precipitate Mn2O3; adding a citric acid solution, sealing, reacting, completely dissolving the precipitate and releasing the iodine elementary substance, adding water and an ascorbic acid-potassium dichromate mixed color developing agent into the solution after the reaction is finished, fixing the volume, sealing, uniformly mixing, and carrying out a color developing reaction in a dark place; a blank sample is used for reference, the culture tail water subjected to color development is placed in a sample pool of a spectrophotometer, the spectrophotometric value of the sample is measured at the wavelength of 360 nm, and the dissolved oxygen concentration is calculated according to a standard curvilinear equation. The method provided by the invention reduces the detection limit of the traditional spectrophotometric method, and has the advantages of high sensitivity, strong anti-interference capability, high speed and rapidness in operation, wide application range, greenness and environmental protection.

The present invention relates to a reagent combination for determining the chemical oxygen demand (COD) in a liquid medium, wherein the reagent combination comprises a first reagent, wherein the first reagent is an acidic solution of mercuric sulfate (HgSO4); a second reagent, wherein the second reagent is an acidic solution containing potassium dichromate (K2Cr2O7); and a third reagent, wherein the third reagent is an acidic solution, characterized in that at least the second reagent or at least the third reagent also contains potassium aluminum sulfate (KAl(SO4)2·12H2O).

The application discloses a kind of aluminum lithium alloy passivation methods, the passivation aluminum lithium alloy is successively included from inside to outside, aluminum lithium alloy core, passivation layer growth film, passivation layer coating film;The sum thickness of the passivation layer growth film and the passivation layer coating film film is 1~1.5 μm;Specifically using potassium dichromate, using magnetic stirrer, forms the passivation film on the surface of aluminum lithium alloy;Aluminum lithium alloy can be added into solid propellant after passivation of the application.The application forms dense passivation film on the surface of aluminum lithium alloy, effectively prevents and insulates the influence of external water vapor on aluminum lithium alloy, maintains the stability of aluminum lithium alloy during storage and use.

The application discloses a testing method for the content of divalent iron ions in EDTA chemical cleaning solution, and aims at the problem that the existing titration method cannot accurately determine the content of divalent iron ions due to the interference of EDTA. Instead of adopting a complex separation step, the method eliminates the interference through two steps. First, the to-be-tested solution is adjusted to be acidic to weaken the complexing capacity of EDTA, and then a sulfur-phosphorus mixed acid solution is added. The strong acidity of sulfuric acid is used to inhibit the complexing reaction and avoid hindering titration. The whole process is based on the principle of titration method, and does not need expensive instruments and reagents, and is low in cost. The operation is simple and does not need professional skills. The application adopts the high-stability potassium dichromate standard solution, reduces the calibration frequency, realizes rapid, convenient, accurate and low-cost determination, and is suitable for on-site detection requirements.

The invention relates to the technical field of determination of chemical oxygen demand (COD) of a catalyst, in particular to a rapid COD determination method for an improved catalyst system, chemical oxygen demand (COD) serves as a key index for measuring the content of reducing substances in a water body, and the content of the reducing substances in the water body is determined through oxidation treatment of potassium dichromate. The amount of potassium dichromate consumed by the oxidized reducing pollutants in the water sample corresponds to the mass concentration of oxygen, and the measurement result directly reflects the pollution degree of the water body. COD is one of core parameters for water environment monitoring and treatment, a traditional COD determination method takes a potassium dichromate oxidation method as a reference, but has the problems of low reaction efficiency, long time consumption, incomplete oxidation caused by a single catalyst, weak anti-interference capability and the like, depends on manual operation, and is inconvenient to operate. In the prior art, the requirements of modern environment monitoring on rapidness, accuracy and automation are difficult to meet due to large reagent dosage and high secondary pollution risk, and for a complex water sample, a traditional method is easy to cause determination deviation and insufficient in data sharing and remote monitoring capability, so that the intelligent development of water environment monitoring is restricted.

The invention relates to an energy-saving building material and application, and belongs to the technical field of building materials, the energy-saving building material comprises the following raw materials: Portland cement, fly ash, fatty acid polyoxyethylene ether sodium sulfate, dodecyl dimethyl betaine, a silicone resin polyether emulsion, a pretreated fiber blend and deionized water; wherein the pretreated fiber blend is prepared from polypropylene fiber, a polyoxyethylene polyoxypropylene block copolymer, potassium dichromate and deionized water together. A large number of closed pores which are small in size and volume difference and good in stability are distributed in the foam concrete prepared according to the selected raw materials and formula, the heat transfer path in the material is increased, the average heat conductivity coefficient of the material is reduced, and the finished product has excellent heat insulation performance, so that the energy-saving effect is outstanding; meanwhile, the pretreated polypropylene fiber is doped into the concrete to disperse or bear the stress generated in the concrete, so that the finished product has excellent crack resistance.

The invention relates to a method for improving Fe < 2 + > detection precision by decarburization through a magnetic separation method. The method comprises the following steps: weighing a detection sample; carrying out magnetic separation on the weighed sample by using a small high-intensity magnetic separator, and separating carbon from iron minerals by virtue of magnetic difference through separation of the magnetic separator; determining the ratio of iron minerals to carbon content in the sample; measuring the ferrous content of the separated iron mineral sample by a potassium dichromate volumetric method; calculating the ferrous content in the whole sample according to the determined proportion of the iron mineral content to the carbon content in the sample; according to the method, the carbon in the test sample is abandoned in advance through the magnetic separation process, so that the titration end point of the potassium dichromate volumetric method is determined more accurately, the detection process is simple and easy to operate, and the accuracy of the test result of the Fe < 2 + > content of the carbonaceous iron minerals is greatly improved.

The application discloses a steel plate enamel high-temperature titanium milk yellow face glaze free of fluorinated salt and nitrate, a preparation method and application thereof, and belongs to the technical field of enamel. The face glaze is prepared from quartz, zero-water borax, rutile, potassium feldspar, trisodium phosphate, potassium carbonate, potassium dichromate and zinc oxide according to specific mass proportions. The preparation comprises raw material mixing, smelting at 1300+ / -10 DEG C under a pure oxygen environment, and rapid cooling after wire drawing detection of the smelting state. The face glaze completely avoids the use of fluorinated salt and nitrate, eliminates fluorine emission and environmental protection equipment blockage problems from the source, the fluorine content of the product is not detected through detection, meets the limit value requirements of the EU REACH regulation, has good color, gloss and firing adaptability, is suitable for a steel plate substrate, has a firing temperature of 840-880 DEG C, and can be used for the production of green and environmentally-friendly enamel products.

The invention discloses a method for manufacturing a reprinting mold, which comprises the following steps of: providing a patterned nickel layer with an optical holographic pattern; the patterned nickel layer is placed in a vacuum chamber with the pressure ranging from 10 <-3 > torr to 10 <-5 > torr, and oxygen plasma is introduced towards the patterned nickel layer in a plasma sputtering mode at the flow ranging from 80 sccm to 120 sccm, so that a plasma type oxide layer covering the optical holographic pattern is formed; forming an electroformed nickel layer on the plasma type oxide layer through electroforming; and separating the electroformed nickel layer from the patterned nickel layer and the plasma type oxide layer on the patterned nickel layer, so that a reprinting holographic pattern corresponding to the optical holographic pattern is formed on the electroformed nickel layer. Therefore, the plasma type oxide layer is formed under the specific implementation conditions (for example, oxygen plasma is introduced at the flow rate of 80-120 sccm) in the sputtering step, so that the plasma type oxide layer can be separated from the electroformed nickel layer under the condition that the structure is not damaged, and then a strong oxidant containing potassium dichromate is replaced.

The present invention relates to a reagent combination for determining chemical oxygen demand (COD) in a liquid medium, the reagent combination comprising a first reagent wherein the first reagent is an acidic solution of mercury sulfate (HgSO4); a second reagent, wherein the second reagent is an acidic solution comprising potassium dichromate (K2Cr2O7); and a third reagent, where the third reagent is an acidic solution, characterized in that at least the second reagent or at least the third reagent further comprises potassium aluminum sulfate (KAl (SO4) 212H2O).

The invention relates to the technical field of chemical analysis, and relates to a method for measuring the content of an iron phase in iron-containing dust slime, which comprises the following steps: 1, preparing an iron-containing dust slime sample, and carrying out ball milling processing on the iron-containing dust slime to obtain an iron phase sample; 2, weighing an iron phase sample A0, placing the iron phase sample A0 in a container, adsorbing magnetic substances in the iron phase sample A0 by adopting a magnet, respectively weighing the adsorbed magnetic substance A1 and the remaining sample A '0, and detecting the content of magnetic metal iron in the magnetic substance A1 by utilizing a potassium dichromate method; step 3, mixing the residual sample A '0 with anhydrous sodium carbonate according to a mass fraction ratio of 1: (2-5), marking the mass fraction ratio of the anhydrous sodium carbonate to the residual sample A' 0 as k, and marking the fully ground and uniformly mixed sample as A '' 0; respectively detecting the contents of wFe < 1 >, wFe < 2 > and wFe < 3 > in the weighed uniformly mixed sample by using a potassium dichromate method; and 4, carrying out normalization calculation on the content results obtained in the step 2 and the step 3 to finally obtain the contents of total iron (TFe), metallic iron (MFe), ferrous iron (Fe < 2 + >) and ferric iron (Fe < 3 + >) in the iron phase sample A0.

The invention provides a method for determining the resultant amount of elements in an iron-based sodium electric precursor based on the total iron content, and the method comprises the following steps: dissolving the iron-based sodium electric precursor by using an acid, then adjusting the pH value by using an alkali to precipitate iron ions so as to obtain an iron precipitate, and then dissolving the iron precipitate by using an acid so as to obtain an iron-containing solution; ferric ions in the iron-containing solution are reduced, and a solution containing ferrous ions is obtained; the method comprises the following steps: removing redundant reducing agents, adding an indicator into a solution containing ferrous ions, titrating by adopting a potassium dichromate standard solution until the solution is colorless and mutates into purple, measuring the total iron content, and calculating the element sum according to the total iron content and the molar ratio of elements in the iron-based sodium electric precursor measured by adopting an ICP (Inductively Coupled Plasma) method. The method comprises the following steps: firstly reducing all Fe < 3 + > in a sample into Fe < 2 + >, then titrating and testing the total iron content by adopting a potassium dichromate standard solution, and then converting the resultant of the elements according to the molar ratio of the elements.

Application of Lysinibacillus fusiformis in removing hexavalent chromium from eutrophic wastewater, belonging to the field of microbial technology. The strain is preserved in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms, with the preservation address being No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, the preservation number being CGMCC No. 10053, and the preservation name being Lysinibacillus fusiformis WTXJ1-4, and the preservation date is November 25, 2014. Through single-factor experiments and orthogonal experiments for optimization, the suitable biological adsorption conditions of this strain for hexavalent chromium in eutrophic wastewater were determined as follows: pH 2.0, initial potassium dichromate concentration 50 mg / L, adsorption time 24 h, wet cell mass dosage 1.0 g / L, adsorption temperature 34 °C, and rotation speed 160 r / min. When reaching equilibrium under these optimized adsorption conditions, the removal rates of hexavalent chromium and total chromium in eutrophic wastewater by viable cells of WTXJ1-4 reached 91.6% - 94.8% and 42.2% - 43.8% respectively. Lysinibacillus fusiformis Viable cells of WTXJ1-4 have strong adsorption-reduction ability, tolerance and resistance to hexavalent chromium in eutrophic wastewater, and their effective ranges are potassium dichromate concentrations of 0 - 100 mg / L, 100 - 300 mg / L, and 300 - 500 mg / L respectively.

The invention relates to the technical field of phosphogypsum harmlessness, in particular to a formula and method for curing soluble phosphorus, eutectic phosphorus, soluble fluorine and ammonia nitrogen in fresh phosphogypsum of a rotary table type vacuum filter. Comprising the following components: ardealite, calcium hydroxide, anionic polyacrylamide, magnesium chloride, aluminum chloride, deacetylated chitin, potassium dichromate and deionized water. Agents adopted by the invention are common industrial agents which are convenient to purchase on a large scale. The medicament is low in cost and has no special requirements for storage and transportation. The agent cost for harmlessly treating each ton of fresh phosphogypsum of the large rotary table type vacuum filter is lower than 30 yuan. According to the method, the concentration of fluoride in the phosphogypsum leachate can be effectively controlled to be 4 mg / L or below.

The present invention provides a contact allergen reagent combination and its use. Specifically, it relates to the use of the contact allergen reagent combination for preparing a kit for diagnosing potential allergens of skin allergies of a subject, wherein the allergen reagent combination includes at least five selected from the group consisting of nickel sulfate, potassium dichromate, disperse blue 106, cobalt chloride, aromatic mixture I, methylisothiazolinone, thimerosal, sodium lauryl sulfate, carbazine mixture, formaldehyde, iodopropynyl aldehyde and p-phenylenediamine. The kit of the present invention can quickly and accurately identify skin allergens of Chinese people, with a high detection rate.

The invention discloses a formula of an eosin staining solution, and every 1000 ml of the eosin staining solution comprises the following components: 5-8 g of eosin which is any one of water-soluble eosin Y or alcohol-soluble eosin Y; 2.5 to 3.5 g of potassium dichromate; 5-25 g of picric acid; 5 to 60 ml of absolute ethyl alcohol; the balance is water, and the water is any one of deionized water or distilled water. According to the eosin staining solution formula disclosed by the invention, the absolute ethyl alcohol not only can promote good dissolution of all the components and effectively ensure a good uniform mixing effect among all the components, but also can be used as a dehydrating agent and can play a role in dehydrating and fixing cells, so that a cell environment in tissues is similar to the tissues, cell coloring in the tissues is facilitated, and the quality of the cells in the tissues is improved. The dyeing liquid has a certain level dyeing effect, is clear in coloring, avoids overdyeing, uneven dyeing and other conditions, utilizes the synergistic effect of potassium dichromate and picric acid, promotes the dissolution of each component, ensures the stability of the dyeing liquid, is simpler to prepare, is not easy to fade, and has a longer period of validity.