128 results about "Chromic Ion" patented technology

The present invention relates to the field of wastewater treatment technology, and more particularly to a process and apparatus for separating and recovering chromium and lead ions from wastewater. The apparatus comprises a flotation sedimentation tank equipped with an inlet pipe and a drain pipe, a feeding mechanism, and a dispersion mechanism. The flotation sedimentation tank is used to receive the wastewater to be treated. The feeding mechanism is disposed within the flotation sedimentation tank and is used to inject a reactant, a collector, and aeration gas into the flotation sedimentation tank. The dispersion mechanism is connected to the feeding mechanism and is used to disperse the reactant, collector, and aeration gas within the flotation sedimentation tank so that they come into full contact with the wastewater. The process comprises: introducing a reactant into the wastewater to cause the chromium ions and lead ions to react, respectively, to produce a chromium precipitate and a lead precipitate; introducing a collector into the wastewater to cause the lead precipitate to combine with the collector to impart hydrophobicity; aerating the wastewater to cause the lead precipitate to form froth; and separating and recovering the froth from the chromium precipitate. The present invention can achieve simultaneous separation and recovery of chromium and lead ions from wastewater, achieving high separation and recovery rates.

The invention provides self-recovery chromium ion doped oxide mechanoluminescence fluorescent powder as well as a preparation method and application thereof. The chemical general formula of the self-recovery mechanoluminescence fluorescent powder is Al2 (1-x) O3: 2xCr < 3 + >, wherein x is equal to 0.3%-5%. The preparation method of the self-recovery mechanoluminescence fluorescent powder comprises the following steps: a, respectively weighing aluminum oxide and chromium oxide according to the molar ratio of each element in the chemical general formula Al2 (1-x) O3: 2xCr < 3 + >; b, grinding and uniformly mixing the weighed raw materials, and firing in air at the temperature of 1300 DEG C for 6 hours; and c, taking out the fired sample, and uniformly grinding to obtain the chromium ion doped oxide mechanoluminescence fluorescent powder. According to the chromium ion doped oxide mechanoluminescence fluorescent powder disclosed by the invention, a measured emission band main peak is located at 694 nm and is located at a biological first window (600-900 nm), and the chromium ion doped oxide mechanoluminescence fluorescent powder is expected to be used as a near-infrared mechanoluminescence biological probe; and the fluorescent powder has the advantages of no need of pre-irradiation and instant self-recovery of luminescence.

The invention provides a water pollution real-time detection and early warning method based on self-adaptive spectral feature fusion, relates to the technical field of environmental monitoring, and aims at spectral data of different incident angles through a self-adaptive segmented spectral enhancement algorithm, a feature enhancement strategy is dynamically adjusted, complementarity of multi-angle spectral information is effectively mined, and the real-time detection and early warning of water pollution are realized. Therefore, the precision and the anti-interference capability of heavy metal ion concentration detection are remarkably improved. And the heavy metal recognition model carries out accurate correction on the spectrum superposition effect and matrix interference in the heavy metal mixed system through the spectrum interference suppression factor, so that the robustness and reliability of concentration detection are further improved. Rapid detection and real-time early warning of pollutant concentration are realized, and the problem of low detection precision caused by mutual interference of spectral characteristics of mixed pollutants of heavy metal ions (especially chromium ions and nickel ions) in industrial wastewater can be solved to a certain extent.

The invention provides an electroplating wastewater dosing feedback regulation method based on online water quality detection, and relates to the technical field of environmental chemical analysis and water quality monitoring, the electroplating wastewater dosing feedback regulation method comprises the following steps: collecting chromium ion concentration parameters, pH value parameters and oxidation-reduction potential parameters of electroplating wastewater, and combining a trained chromium ion reduction model to carry out real-time calculation and analysis; and dynamic correction and closed-loop feedback adjustment of the dosage are realized. Therefore, the accuracy and the response speed of dosing control can be remarkably improved, the problem of excessive dosing or insufficient dosing of the medicament is effectively reduced, and meanwhile, the stability and the standard-reaching rate of wastewater treatment are ensured, so that the economical efficiency and the environmental protection property of wastewater treatment are improved.

The invention belongs to the technical field of scintillation materials, and particularly relates to a chromium ion doped near-infrared scintillation crystal and a preparation method and application thereof. The chromium ion-doped near-infrared scintillation crystal has a molecular formula of A3B2-xCrxC3O12, x is greater than or equal to 0.005 and less than or equal to 0.1, and after a chromium ion-doped ultraviolet-visible light inorganic scintillator is adopted, light is emitted at the wavelength of 650-950 nm and has good wavelength matching with a silicon photoelectric detector. Besides, single crystal growth is carried out by adopting a Czochralski method, the crystal growth process is optimized, the ion doping concentration is regulated and controlled, the scintillation performance of the chromium ion doped near-infrared scintillation crystal in the near-infrared band is improved, the requirement of the chromium ion doped near-infrared scintillation crystal in the radiation detection field is further met, and the problem that an existing scintillation crystal is low in transparency is solved.

The invention relates to the technical field of coatings, in particular to a PVD (Physical Vapor Deposition) coating process method applied to a galvanized sheet stamping die, which comprises the following steps of: pretreating the die, cleaning the surface of the die by a wet process, placing the die in a vacuum deposition cavity, vacuumizing, and heating to a preset temperature in an inert gas environment; plasma pretreatment is conducted on the surface of the mold, a high-power pulse magnetron sputtering cathode of a chromium target is selected to discharge in the argon working environment to generate plasma rich in chromium ions, and negative bias voltage is applied to the mold; starting at least one unbalanced magnetron sputtering cathode, gradually increasing the target current by the unbalanced magnetron sputtering cathode in a current ramp-up mode so as to improve the target voltage, and synchronously introducing nitrogen as a reaction gas, so that a nitride transition layer is deposited on the surface of the mold; and a high-power pulse magnetron sputtering cathode and an unbalanced magnetron sputtering cathode synchronously work on the transition layer to carry out multi-source reactive sputtering deposition, so that a multi-layer hard coating formed by alternating titanium aluminum vanadium and chromium nitride is formed. By combining the high-power pulse magnetron sputtering technology and the unbalanced magnetron sputtering technology, the problems that in the prior art, a coating is poor in adhesive force and insufficient in high temperature resistance are solved.

The application belongs to the technical field of composite membrane materials, and particularly relates to a preparation method and application of a super-hydrophilic composite membrane capable of removing various pollutants in water bodies; the preparation method comprises the following steps: preparing a bimetallic organic framework material FeZr-MOF through a one-step solvothermal method; dispersing FeZr-MOF powder in a suitable solvent, mixing, adding polyvinylidene fluoride and polyvinylpyrrolidone, stirring under water bath conditions at 30-80 DEG C, obtaining a uniformly mixed casting solution, and then preparing a FeZr-MOF / PVDF composite membrane through a non-solvent induced phase separation method after ultrasonic defoaming treatment; then, a polyaniline coating layer is in-situ polymerized on the surface of the composite membrane to obtain a PANI / FeZr-MOF / PVDF composite membrane. The super-hydrophilic composite membrane capable of removing various pollutants in water bodies has good effects in oil-water separation, removal of antibiotics and chromium ions in water and the like.

The invention provides a method for detecting and analyzing heavy metal chromium in high-aluminum ore and red mud, and belongs to the field of mineral analysis and detection. The method comprises the following steps: melting a mixture of a sample to be detected and a strong alkaline flux to obtain a melt; extracting and dissolving the melt by using a dilute acid solution to obtain a leaching solution; a strong oxidant and a catalyst are added into the leachate, so that chromium ions in the leachate are oxidized into hexavalent chromium ions, and hexavalent chromium conversion liquid is obtained; adding an alkali carbonate solution into the hexavalent chromium conversion solution to adjust the pH value of the hexavalent chromium conversion solution to 8-10 to obtain a mixed solution; filtering the mixed solution to obtain a chromium-containing filtrate; and quantifying the total chromium content in the chromium-containing filtrate by adopting a spectrophotometric method. The detection and analysis method provided by the invention can ensure that chromium existing in lattices of the high-aluminum ore and red mud sample is completely released, and main matrix interference elements such as aluminum, iron, calcium and magnesium in the sample can be effectively separated, so that accurate determination of the total chromium content in the to-be-detected sample is realized.

The disclosure generally relates to ready to drink electrolyte solution. In particular the disclosure relates to a ready to drink electrolyte solution comprising isomaltulose, glucose, sodium ions, chromium ions and water; wherein the glucose concentration is greater than or equal to 0.9g / 100ml, and wherein the theoretical glycemic index of the solution is equal to or less than 55. The disclosure also relates to a method of manufacturing said ready to drink electrolyte solution. The disclosure also relates to a method of rehydrating a patient suffering from cancer, diabetes, acute or chronic illness, or a gastrointestinal disorder by using said ready to drink electrolyte solution.

The present invention relates to the use of a trivalent chrome plating bath composition for the electrodeposition of a hard chrome layer with a thickness of 1 µm or more, the composition comprising (A) trivalent chromium ions in an amount of 5-40 g / l, (B) at least one anion selected from sulfate, chloride, bromide and methanesulfonate, (C) at least one carboxylate ion selected from formate and acetate, (D) at least one buffer substance selected from ammonia, boric acid, carboxylic acids with 2 to 8 carbon atoms other than component (C) and salts thereof, and aluminium salts, and (E) 0.01 to 100 g / l of at least one specific compound which comprises a sulfonate group and a sulfide or disulfide group. Other aspects of the invention relate to a hard chrome plating process, a hard chrome plating layer and a hard chrome plated article.

The application relates to a chromium ion form analysis method based on electrochemical and Raman bimodal detection signals. Au-Ag Janus NPs solution is added dropwise on the surface of a glassy carbon electrode, the DPV signal value and the Raman signal value of a to-be-detected solution containing Cr 6+ and Cr 3+ are detected, the concentration of Cr 6+ in the to-be-detected solution is obtained, Cr 6+ in the to-be-detected solution containing Cr 3+ and Cr 3+ is oxidized into Cr 6+ under the conditions of strong alkalinity and heating by using potassium permanganate, then a reducing agent is added to obtain a mixed solution, the concentration of Cr 6+ in the mixed solution is detected through the DPV signal value and the Raman signal value, Cr 3+ is completely converted into Cr 6+ , the total chromium concentration is measured, finally the concentration of Cr 3+ is obtained by subtraction, and finally the chromium ion form analysis is realized. The method improves the accuracy and efficiency of Cr ion form detection, and is suitable for rapid analysis of Cr ion forms in environment and biological samples.

A kind of low concentration chromium-containing leather wastewater treatment method, comprising the following steps: step one, after adjusting leather wastewater, send into membrane separator and obtain concentrated solution and waste liquid;Step two, send waste liquid into resin adsorption tank, and carry out adsorption recovery to chromium ion;Step three, send concentrated solution into hydrolysis fermentation tank and carry out hydrolysis fermentation;Then send into anaerobic tower and carry out further decomposition;Step four, send concentrated solution of step three into multi-medium filter and treat, the supernatant obtained is sent into resin adsorption tank;The waste of backwashing multi-medium filter is transported to adjusting tank and is treated again;Step five, the wastewater treated after resin adsorption tank is treated biochemically;Step six, resin adsorption tank is treated by desorption, then the pH of desorption waste liquid is adjusted, so that chromium ion is precipitated to obtain chromium precipitation recovery;The present application not only recycles chromium ion in leather wastewater, but also can carry out reduction treatment to leather waste in leather wastewater, reduce the pollution to environment.

The utility model discloses a device for preparing a leather tanning agent by recycling chromium-containing wastewater, which comprises an equipment base and a recycling sedimentation tank, the recycling sedimentation tank is mounted on the equipment base, and a uniform reactant moving and throwing structure is mounted on the recycling sedimentation tank; the utility model relates to the technical field of waste water recovery equipment, and has the beneficial effects that the problems that in the existing waste water treatment, reactants are directly and manually fed into chromium-containing waste water for reaction and precipitation, but fixed feeding is mostly adopted, so that the reactants are not fully mixed with the waste water, the precipitation efficiency of chromium ions and the quality of tanning agents are influenced, and the production cost is high are solved; and the problems that the operation complexity and the energy consumption are increased due to the fact that the sediment directly sinks at the bottom of the reaction tank, cleaning and maintenance are inconvenient, and an integrated movable throwing and sediment discharging system is lacked are solved.

A luminescent material is a complex with the following structural formula: wherein R and R' are independently selected from oxygen, amino, C1-C18 straight-chain or branched alkyl-substituted amino, phosphin, C1-C18 straight-chain or branched alkyl-substituted phosphin, sulfur, and selenium; R1, R2, R3, R4, R5, and R6 are independently selected from hydrogen, C1-C18 straight-chain or branched alkyl or halogen-substituted C1-C18 straight-chain or branched alkyl, aromatic... Aromatic groups such as benzene, thiophene, and furan, n = 1–3, are used to construct cyclic ligand skeletons with different half-ring numbers. Ln is one of the following: cerium trivalent ion, europium divalent ion, ytterbium divalent ion, and samarium divalent ion. M is one of the following: manganese divalent ion, cobalt trivalent ion, chromium trivalent ion, vanadium trivalent ion, and ferric trivalent ion. X is a monovalent ion, such as halogen, cyanide, thiocyanate, isothiocyanate, etc., m = 0–3, l = 3–6. X acts as a monodentate ligand or as a bridging bidentate ligand.

The invention discloses a hydrogen peroxide-based vanadium-chromium separation method, which comprises the following steps: (1) adding hydrogen peroxide into a solution containing vanadium ions and chromium ions, controlling the temperature and pH of the solution, and reacting for a period of time; and (2) separating the solution from the precipitate in the solution to obtain a solution with reduced chromium ion content and a precipitate with enriched chromium ions. The invention further discloses application of hydrogen peroxide in separation of vanadium and chromium in the vanadium-chromium symbiotic leachate. According to the method, the selected impurity removal agent hydrogen peroxide is low in price and easy to obtain, the production cost is greatly reduced, operation is easy and convenient, the whole impurity removal process is simple in step and easy to operate and reproduce, and complex equipment and tedious process conditions are not needed.

The application discloses a preparation method of a chromium-containing geopolymer material and application of the chromium-containing geopolymer material in a steelmaking process, and belongs to the field of geopolymer materials. The preparation of the chromium-containing geopolymer material mainly utilizes an adsorption method and a direct incorporation method to add chromium ions into the geopolymer material. The chromium-containing geopolymer material has wide raw material sources, simple preparation process and low production cost. The chromium-containing geopolymer material, a reducing agent and slag-making material are added before molten steel enters refining, the chromium element in the chromium-containing geopolymer material is reduced into metallic chromium into molten steel by the reducing agent in the process of a steelmaking converter, complete or partial replacement of ferrochrome is realized, and the smelting cost of the chromium-containing steel is reduced. Meanwhile, the application can also realize large-scale treatment of chromium-containing wastewater, is an adsorbent with excellent performance, realizes high added value utilization of solid waste resources, and greatly reduces environmental pollution caused by ferrochrome, and the chromium-containing geopolymer material prepared by the method has great advantages and application prospects in the steelmaking process.

The invention relates to a chromium ion single-doped ultra-wideband near-infrared fluorescent material, a preparation method thereof and an LED device, and belongs to the technical field of luminescent materials. The chemical composition formula of the material is Ca2Sc1-yYyGa3-3xSn2O12: xCr, x is larger than or equal to 0.003 and smaller than or equal to 0.10, and y is larger than or equal to 0.00 and smaller than or equal to 1.00. The material is high in phase purity, simple in preparation process, simple and convenient to operate, environment-friendly and high in synthesis efficiency. Under excitation of 475-500 nm, the emission spectrum of the material covers the range of 600-1600 nm, the material has high luminous intensity in a first near-infrared region (about 855 nm) and a second near-infrared region (about 1300 nm), and the full width at half maximum can reach 200-655 nm. Meanwhile, the material has good absorption in the range of 400-700 nm, can be effectively matched with a commercial blue light LED chip, and is suitable for preparing a high-performance near-infrared LED light source. Compared with the prior art, the material provided by the invention not only can realize ultra-wideband emission covering a first near-infrared area and a second near-infrared area, but also is adjustable in emission peak position and high in absorption characteristic and commercial blue light chip compatibility, and is beneficial to development of high-efficiency and high-stability near-infrared LED devices.

The invention relates to a chromium ion morphology analysis method based on electrochemical and Raman bimodal detection signals. Dropwise adding an Au-Ag Janus NPs solution on the surface of the glassy carbon electrode, and detecting a DPV signal value and a Raman signal value of a to-be-detected solution containing Cr < 6 + > and Cr < 3 + > to obtain the concentration of Cr < 6 + > in the to-be-detected solution; the method comprises the following steps: oxidizing Cr < 3 + > in a to-be-detected solution containing Cr < 6 + > and Cr < 3 + > into Cr < 6 + > by using potassium permanganate under the conditions of strong alkalinity and heating; then adding a reducing agent to obtain a mixed solution; detecting the Cr < 6 + > concentration of the mixed solution according to the DPV signal value and the Raman signal value; and completely converting Cr < 3 + > into Cr < 6 + >, measuring the concentration of total chromium, and finally subtracting to obtain the concentration of Cr < 3 + >, thereby finally realizing chromium ion morphological analysis. The method provided by the invention improves the accuracy and efficiency of Cr ion morphology detection, and is suitable for rapid analysis of Cr ion morphology in environmental and biological samples.

The invention provides a method for removing hexavalent chromium ions in a water body, and relates to the technical field of treatment of wastewater containing heavy metal ions, and the method comprises the following steps: providing haematococcus pluvialis, activating the haematococcus pluvialis, and separating and purifying the haematococcus pluvialis; the method comprises the following steps: providing a culture medium and a hexavalent chromium ion-containing water body, adding the hexavalent chromium ion-containing water body into the culture medium to prepare the hexavalent chromium ion-containing culture medium, and culturing the purified haematococcus pluvialis by using the hexavalent chromium ion-containing culture medium. The purified haematococcus pluvialis grows on a culture medium containing hexavalent chromium ions, astaxanthin and beta carotene with high content are generated in cells, the cells have high reducing capacity, and high-valence Cr (VI) is reduced into Cr (III), so that the content of Cr (VI) in a water body is reduced, and the toxicity of high-valence chromium ions to algae cells is reduced.

The application discloses a chromium-doped ultra-wideband near-infrared fluorescent material and a preparation method thereof. 2‑x A x Si2O7:yCr M , wherein A is one or more of Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Ga, 0<=x<=0.5, 0.001<=y<=0.3, and M is one or more of 3+ and 4+. The preparation method comprises the following steps: taking raw materials according to the stoichiometric ratio, grinding and mixing; pre-calcining at 600-1200 DEG C under an air atmosphere; grinding again after cooling, calcining at 1200-1600 DEG C, keeping warm, and cooling to room temperature. The fluorescent powder can be efficiently excited by blue light, emits near-infrared light covering the NIR-I and NIR-II regions, and the peak position and half-height width of the emission spectrum can be regulated by adjusting the molar concentration of A ion replacing Sc and the chromium ion doping concentration.

The present invention belongs to the technical field of rolled copper foil surfaces, and specifically relates to a rolled copper foil surface treatment method, copper foil for adhesive-free flexible copper-clad laminates, and their applications. The rolled copper foil surface treatment method comprises the following steps: using the rolled copper foil as a cathode, performing a micro-roughening treatment in an electrolyte, thereby obtaining a micro-roughened layer on the copper foil; the electrolyte being an acidic solution of copper and nickel ions; immersing the copper foil with the micro-roughened layer in an alloy solution containing nickel ions for alloying treatment to obtain an alloyed layer; immersing the copper foil with the alloyed layer in an anti-oxidation solution containing chromium ions, zinc ions, and sodium sulfate for anti-oxidation treatment to obtain an anti-oxidation layer; and spraying a coupling agent solution on the surface of the anti-oxidation layer. A two-layer flexible copper-clad laminate prepared from the surface-treated rolled copper foil has a high oxidation resistance temperature and peel strength, and the polyimide film has high transparency after etching.

This application discloses a hydrochloric acid-based vanadium-iron-chromium electrolyte, its preparation method, and a flow battery, relating to the field of batteries. The hydrochloric acid-based vanadium-iron-chromium electrolyte contains 1.0~2.5 mol / L vanadium ions, 0.15~2.0 mol / L ferrous ions, 0.1~1.7 mol / L chromium ions, 3.0~4.5 mol / L hydrogen ions, and 0.001~0.05 mol / L hydrogen evolution inhibitor. The technical solution of this application utilizes a hydrochloric acid-based vanadium-iron-chromium electrolyte formed with specific concentrations of vanadium ions, ferrous ions, chromium ions, hydrogen ions, and a hydrogen evolution inhibitor. This electrolyte is suitable for use as the positive and negative electrode electrolytes in flow batteries, significantly improving the energy efficiency and cycle stability of the flow battery. Furthermore, the introduction of relatively inexpensive iron reduces the system's dependence on expensive vanadium resources and lowers production costs.

The invention discloses a chromium removal treatment method for chromium-containing wastewater generated by pretreatment of an aluminum material. The chromium removal treatment method comprises the following steps: S1, collecting the chromium-containing wastewater generated by pretreatment of the aluminum material into a water collecting tank; s2, sulfuric acid is added into the chromium-containing wastewater, and the pH value is adjusted to be 2.5 or below; s3, pumping the chromium-containing wastewater into a reaction tank, adding a chromium removal agent, adding alkali to adjust the pH value to 8-8.5, and adding polyacrylamide to generate a precipitate; s4, pumping the reacted solution into a filter press for filter pressing, pressing precipitates into slag blocks, and collecting the slag blocks to delegate a third party for treatment; meanwhile, raw water is generated. According to the treatment method provided by the invention, chromium ions in the chromium-containing wastewater can be effectively removed, the chromium removal effect is ensured, and the production cost is further saved while the treatment cost is reduced.

The invention discloses a method for removing heavy metal chromium ions in wastewater, and belongs to the technical field of industrial wastewater treatment and heavy metal pollution treatment. The method comprises the following steps: constructing a packed bed electrodialysis system in which a light chamber is filled with an ion exchanger, sequentially introducing chromium-containing wastewater to be treated into the light chamber, respectively introducing a sodium sulfate aqueous solution into a concentrated chamber and a pole chamber, applying direct current, and adopting frequent pole reversal operation. According to the method, deep removal is achieved through selective adsorption of the ion exchanger on chromium ions, efficient separation and concentration of the chromium ions are achieved through an ion channel constructed by the direct-current electric field, the ion exchange membrane and the ion exchanger, and meanwhile in-situ regeneration and reuse of the ion exchanger are achieved by periodically switching the direction of the electric field. The continuous advanced treatment of the chromium-containing wastewater can be realized, the hexavalent chromium concentration of the effluent is stably lower than 0.5 mg / L, the chromium recovery rate exceeds 90%, secondary hazardous waste pollution is avoided, the operation energy consumption is low, the cost is low, and large-scale industrial application is easy.

The invention belongs to the technical field of adsorption materials, and particularly relates to a preparation method and application of a high-entropy adsorption material. The method comprises the following steps: dissolving soluble salts of three or more divalent ions and two or more trivalent ions in water to prepare a high-entropy stock solution; the method comprises the following steps: adjusting the pH value of a diethylenetriamine aqueous solution with a sodium hydroxide solution under stirring, then slowly adding a chloroacetic acid aqueous solution, and continuously stirring for reaction to obtain a modified solution; the preparation method comprises the following steps: soaking spanishneedles herb or bone sponge powder in a modification solution to obtain a modified carrier material, adding the modified carrier material into a high-entropy stock solution, adding a mixed aqueous solution of sodium hydroxide and sodium carbonate as a precipitator, reacting, and carrying out suction filtration to obtain a precipitate and a filtrate; and washing the precipitate with a diethylenetriamine pentaacetic acid solution, drying, and grinding to finally obtain the high-entropy adsorption material. The material has high chlorine adsorption performance, and can be applied to the fields of wastewater adsorption chlorine, fluorine, molybdenum and chromium ion treatment and the like.

The present invention refers to a controlled method for depositing a chromium or chromium alloy layer on at least one substrate, the method comprising the steps (a) providing an aqueous deposition bath, wherein the bath comprises - trivalent chromium ions, - bromide ions, - alkali metal cations in a total amount of 0 mol / L to 1 mol / L, based on the total volume of the deposition bath, and the bath has - a target pH within the range from 4.1 to 7.0, (b) providing the at least one substrate and at least one anode, (c) immersing the at least one substrate in the aqueous deposition bath and applying an electrical direct current such that the chromium or chromium alloy layer is deposited on the substrate, the substrate being the cathode, wherein during or after step (c) the pH of the deposition bath is lower than the target p H, (d) adding NH4OH and / or NH3 during or after step (c) to the deposition bath such that the target pH of the deposition bath is recovered.

This invention discloses a metal-organic framework material in which sulfonic acid and carboxylic acid groups are simultaneously coordinated with chromium ions, its preparation method, and its application. Belonging to the field of crystalline materials technology, the chemical formula is [Cr(OH)(SO3)(CO2)(C6H4)], and the ligand is p-sulfobenzoic acid. It is prepared by the following steps: p-sulfobenzoic acid and chromium chloride hexahydrate are ground and mixed to obtain a premix; the premix is ​​heated to 150-250℃ and reacted for 12-144 hours; after the reaction, the product is washed with ethanol, centrifuged, and dried to obtain the chromium-based metal-organic framework material. The obtained chromium-based metal-organic framework material exhibits excellent proton conductivity, with a conductivity reaching 8.54 × 10⁻⁶. ‑3 S·cm ‑1 (98%RH).

The invention relates to a method for treating chromium-containing wastewater by ion exchange, which comprises the following steps: (1) feeding chromium-containing wastewater into a primary cation exchange carbon fiber column, and sequentially backwashing, regenerating and leaching saturated cation exchange carbon fibers; (2) effluent in the step (1) enters an anion exchange fiber column, the anion exchange fiber column is composed of a second-stage anion exchange fiber column and a third-stage anion exchange fiber column which are connected in series, and saturated anion exchange fibers are sequentially subjected to backwashing, regeneration and leaching; and (3) enabling the anion exchange fiber regenerated eluent to enter a four-stage sulfonic cation exchange resin column. The method is suitable for treating industrial wastewater with relatively complex Cr (VI) pollution conditions, chromium ions in the wastewater are removed by adopting a multi-stage ion exchange coupling method, the chromium content in the treated wastewater can reach the national discharge standard, and the method has the characteristics of stable treatment effect, economy and high efficiency.

The invention relates to the field of passivation solutions, and particularly discloses a trivalent chromium black zinc passivation solution free of fluorine, nickel and phosphorus and a preparation process of the trivalent chromium black zinc passivation solution. The passivation solution comprises the following components: 400-600 g of pure water, 10-15 g of chromic nitrate, 1-3 g of maleic acid, 2-4 g of tartaric acid, 3-5 g of citric acid, 1.5-3 g of borax, 3-5 g of sulfosalicylic acid, 5-8 g of ferrous sulfate, 4-6 g of sodium nitrate, 2-4 g of a corrosion inhibitor, 1-1.5 g of a membrane surface conditioning agent, 1-3 g of an antioxidant and 2-5 g of a blackening enhancer. A complexing system is adopted to stabilize release of trivalent chromium ions, a passivation film layer is compact, uniform and not prone to floating, stable generation of the passivation film is facilitated, the passivation time range is wide, and the corrosion inhibitor is added for efficient corrosion inhibition; the blackening effect of the combined action of the blackening enhancer containing the molybdenum element and ferrous ions is adopted, and through the synergistic effect of the corrosion inhibitor, the blackening enhancer and other raw materials, the existing technical problems that an existing passivation solution is poor in appearance texture, high in equipment corrosion, insufficient in environmental protection property, low in film forming stability, high in blackening system cost, large in pollution and the like are solved.

The present invention discloses an industrial wastewater purification treatment device, which relates to the field of wastewater treatment technology and includes a support frame, wherein a precipitation component is provided at the top of the support frame near one side edge, and an extraction component is provided at the top of the support frame near the other side edge. The industrial wastewater purification treatment device, after the separation of chromium ions in the wastewater and the wastewater is completed, pours a certain amount of resin into the interior of an annular groove, transports the wastewater to the interior of a stirring tank, and stirs the wastewater with a stirring rod so that the chromium ions in the chromium hydroxide are mixed with the adsorption resin, thereby realizing the extraction and storage of chromium in the wastewater, preventing the industrial wastewater from containing a large amount of metallic chromium from polluting the environment and causing waste of resources, and solving the problem that in the prior art, industrial wastewater containing chromium is mostly purified by precipitation and the metallic chromium in the wastewater cannot be recovered, resulting in waste of resources.