17 results about "Potassium dichromate" patented technology

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 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 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 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 discloses a FeO content determination method suitable for multi-lithologic rock, and relates to the technical field of geological analytical chemistry and rock geochemistry. The method comprises the following steps: step 1, sample pretreatment: wetting a rock powder sample with water, adding hydrofluoric acid (HF) and a near-boiling dilute sulphuric acid solution, and covering and sealing; step 2, heating and decomposing: heating and decomposing the mixture in the step 1 at 200 + / -10 DEG C for 10-20 minutes; step 3, complexing and cooling with mixed acid: adding sulfur-phosphorus mixed acid into the heated solution, and then immediately cooling to room temperature in a water bath; and step 4, titration determination: adding a sodium diphenylaminesulfonate indicator into the cooled solution, titrating with a potassium dichromate standard solution until the solution presents stable light purple, and recording the consumed volume V1. The optimized HF-near-boiling H2SO4 system can efficiently decompose various rocks from acidity to super-basic property, the problem that indissolvable samples such as peridotite and the like cannot be completely decomposed by a traditional method is solved, and the sample applicability is wide.

A method for obtaining a stable suspension of graphene oxide nanoparticles and carbon nanotubes. The method comprises: preparing graphene nanoparticles of size 70-150 nm, graphene oxide nanoparticles, in the process 0.7 g of potassium dichromate is added to 2 g of 96-98% sulfuric acid, 1 g of graphene nanoparticles is introduced, washed with water to a pH of 5.5; the graphene oxide nanoparticle suspension is dispersed in an ultrasonic disperser for 1 minute, 0.5 ml of ethanol is added to the carbon nanotubes, the resulting mixture is introduced into the graphene oxide nanoparticle suspension and dispersed for 5 minutes. In the method, the suspension contains graphene oxide nanoparticles at a concentration of 0.02 g / L or 0.03 g / L; the mixture containing 0.75 g of carbon nanotubes is introduced into the graphene oxide nanoparticle suspension at a concentration of 0.02 g / L, and the mixture containing 0.5-1 g of carbon nanotubes is introduced into the graphene oxide nanoparticle suspension at a concentration of 0.03 g / L.

The invention discloses a method for detecting manganese dithionate in a pyrolusite desulfurization solution, and belongs to the technical field of environmental hydrometallurgy. Drying potassium dichromate to constant weight, and preparing a potassium dichromate standard solution; filtering the desulfurized solution, transferring the filtrate into a COD (Chemical Oxygen Demand) digestion tube, adding a sulfuric acid solution and a potassium dichromate standard solution, and uniformly shaking to construct a reaction system; putting the digestion tube into a COD digestion instrument, setting temperature and time for digestion, transferring the solution into a conical flask, washing the digestion tube with water, and merging the washing solution into the conical flask to obtain a mixed solution; cooling the mixed solution to room temperature, titrating with an ammonium ferrous sulfate solution, dropwise adding an indicator, judging an end point according to color change, and recording solution consumption; calculating the content of residual potassium dichromate according to the concentration and consumption of the ammonium ferrous sulfate solution, and calculating the content of manganous dithionate in the desulfurization solution according to the difference between the initial amount and the residual amount of the potassium dichromate and the reaction stoichiometric ratio of the manganous dithionate to the potassium dichromate. The method is accurate and efficient in determination, simple and convenient to operate and low in reagent cost, and has remarkable industrial popularization value.

The invention discloses a chloride ion-free esterified fiber micro-smoke firecracker medicament and a preparation method thereof. Comprising sodium bicarbonate, potassium hydroxide or sodium hydroxide, castor oil, methyl acetate, ethyl formate, ferrocene, manganese dioxide, potassium dichromate and corncob powder fibers. The invention relates to an environment-friendly environment-friendly detergent, which is characterized by comprising 15-25 parts by weight of sodium bicarbonate, 4-10 parts by weight of potassium hydroxide or 8-12 parts by weight of sodium hydroxide, 12-22 parts by weight of castor oil, 25-35 parts by weight of methyl acetate, 25-35 parts by weight of ethyl formate, 6-8 parts by weight of potassium dichromate, 10-22 parts by weight of ferrocene, 2-5 parts by weight of manganese dioxide, 100-200 parts by weight of corncob fiber, and 6-8 cubic meters of water. The preparation method comprises the following steps: crushing a fiber coarse material, soaking in a pool, boiling, rinsing, carrying out centrifugal spin-drying, air-drying, squeezing, distilling, carrying out esterification reaction, adding elements such as potassium, sodium, iron, manganese and the like, sieving, mixing and the like to prepare a finished product. The invention has the advantages of no chlorine salt and sulfide, slight smoke, no toxicity, no pungent smell, no harm to human body, safety, environmental protection and the like.

The present application relates to the technical field of catalyst chemical oxygen demand COD determination, in particular to a COD rapid determination method for improving catalyst system, the chemical oxygen demand COD is a key index for measuring the content of reducing substances in water, after potassium dichromate oxidation treatment, the mass concentration of oxygen corresponding to the amount of potassium dichromate consumed by the oxidized reducing pollutants in the water sample, the determination result directly reflects the degree of water pollution. COD is one of the core parameters of water environment monitoring and treatment, the traditional COD determination method takes potassium dichromate oxidation method as the benchmark, but there are problems such as low reaction efficiency, long time consumption, incomplete oxidation caused by single catalyst, weak anti-interference ability, etc., relying on manual operation, large amount of reagent, high risk of secondary pollution, which is difficult to meet the demand of modern environmental monitoring for rapid, accurate and automatic, for complex water sample, the traditional method is easy to appear determination deviation, the data sharing and remote monitoring ability is insufficient, which restricts the intelligent development of water environment monitoring.

This application relates to the field of environmental monitoring and water quality analysis technology, and in particular to a mixed reagent, test reagent tube, and digestion method for COD detection of petrochemical wastewater. The components, by mass percentage, are: sulfuric acid 75.0–90.0%, potassium dichromate 0.5–1.0%, silver sulfate 1.0–2.7%, scandium sulfate 0.01–0.07‰, potassium hydrogen phthalate 0.1–0.25‰, glucose 0.1–0.25‰, with the remainder being pure water; the mixed reagent does not contain mercuric sulfate. This application enables mercury-free and highly efficient digestion of high-salt, high-organic-content petrochemical wastewater, improves the oxidation efficiency of benzene compounds and polycyclic aromatic hydrocarbons, reduces the detection limit to below 5 mg / L, and the wastewater is easy to treat, combining high accuracy with environmental friendliness.

The invention discloses a Cr / Fe co-doped K0. 5Mn4O8 material and a preparation method thereof, and belongs to the field of inorganic materials. The method comprises the following steps: dissolving potassium dichromate, ferric nitrate nonahydrate, urea, a manganous nitrate aqueous solution and potassium permanganate in purified water, and putting the solution into a hydrothermal reaction kettle for constant-temperature reaction. And filtering and drying the reaction product, calcining in a muffle furnace, and cooling to obtain the Cr / Fe co-doped K0. 5Mn4O8 material. According to the method, the electrochemical performance of the K0. 5Mn4O8 material is effectively improved through co-doping of Cr and Fe elements. The obtained material presents a unique morphology in which a micron-sized laminated blocky matrix and nanoparticles are closely symbiotic on a microstructure, and the micron and nano composite structure is beneficial to increasing the contact area between an electrode and an electrolyte, providing more ion migration channels, buffering the volume change in the cyclic charging and discharging process, and improving the electrochemical performance of the electrode. Therefore, the performance of the material in the positive electrode of the zinc ion battery is improved.

The invention discloses purple ceramic ink as well as a preparation method and application thereof. The purple ceramic ink is prepared from the following raw materials: metastannic acid, light calcium carbonate, quartz powder, potassium dichromate, calcium fluoride, potassium chromate, a solvent and a dispersing agent. When the purple ceramic ink is used for preparing domestic porcelain, bright purple can be generated, the color development effect is good, and the color development requirement of the domestic porcelain can be met.

The invention discloses a PVD plated part reworking method and a PVD plated part reworking product, the PVD plated part reworking method comprises the steps that a metal part is provided, the metal part comprises a metal base material, an anodic oxide film layer and a PVD film layer, the surface of the metal base material is provided with a corrosion area, the anodic oxide film layer covers the surface of the metal base material comprising the corrosion area, and the PVD film layer covers the surface of the metal base material comprising the corrosion area; the PVD film layer covers the surface, deviating from the metal base material, of the anodic oxidation film layer; the metal part is immersed in a first reagent for deplating so as to remove the PVD film layer, and the first reagent comprises potassium dichromate; the metal piece is immersed in a second reagent for anode stripping, so that an anode oxide film layer is removed, and a corrosion area of the metal base material is stripped, and the second reagent comprises potassium hydroxide; the metal piece is immersed in a third reagent to be subjected to corrosion removal, so that the corrosion area of the metal base material is further removed; and the metal piece is coated, so that a new PVD film layer is formed on the surface of the metal base material. According to the method, the metal piece with the corrosion marks can be reused, and the production cost is effectively reduced.

Methods and compositions for rapid verification of cleaning performance on surfaces in cleaning-in-place (CIP) systems and in cleaning-in-place (COP) systems and in high flow areas. The solution comprises alkali metal hydroxide; one or more oxidizing compounds, wherein the one or more oxidizing compounds comprise sodium hypochlorite, potassium hypochlorite, sodium persulfate, potassium persulfate and monopersulfate; and one or more compounds selected from the group consisting of potassium permanganate, sodium permanganate, potassium dichromate, and sodium dichromate. In some examples, the solution also includes potassium tripolyphosphate, sodium tripolyphosphate, or other tripolyphosphate. The substrate is in contact with the solution, and a chromogenic reaction may occur indicating the presence of an organic substance or non-organic contaminant. The chromogenic reaction may occur within less than 30 minutes and at a temperature of 10 DEG C to 60 DEG C.

The present application belongs to the technical field of preparation and application of carbon nanomaterials, and particularly relates to a preparation method and application of sorghum red carbon quantum dots. The present application mainly solves the problems of existing chromium (VI) ion detection methods, such as environmental pollution and poor safety, and effectively detects Cr (VI) in tap water and wastewater by synthesizing carbon quantum dots from sorghum red and anhydrous p-aminobenzenesulfonic acid through a hydrothermal method. The present application has the advantages of convenient raw material source, low cost, abundant supply, simple processing technology, safety, non-toxicity, natural color, and simple preparation operation steps. The sorghum red carbon quantum dots prepared by the present application have water solubility, can be used for detecting the concentration of chromium (VI) ions in water, have a specific recognition effect on potassium dichromate, can be used for detecting potassium dichromate, have good selectivity, and have high sensitivity.

This application proposes a polishing slurry for ultra-precision optical components in laser equipment and its preparation method, to solve the problem that the chemical corrosion rate and mechanical removal rate of polishing slurries for fused silica are difficult to precisely match, resulting in low processing efficiency or surface corrosion pits. The polishing slurry contains the following components by weight percentage: 5-15% colloidal silica, 5-12% cerium oxide, 2-8% boron carbide, 5-12% silicon carbide, 2-8% iron oxide, 3-10% potassium dichromate, 5-15% citric acid, 2-8% tartaric acid, 1-5% polyvinylpyrrolidone, 0.5-3% ammonium polyacrylate, 0.1%-1.0% surface remodeling agent, 0.5%-2.0% amino acid-based amphoteric surfactant, and 0.01%-0.1% nanodiamond, with the balance being deionized water; the surface remodeling agent is at least one of zirconium fluoride and ammonium fluorozirconate. The resulting component has a surface roughness of less than 0.1 nanometers, achieving atomic-level smoothness without scratches or pitting; subsurface microcracks are filled and repaired by a zirconium oxide layer.