198 results about "Chromic Ion" patented technology

The invention relates to the technical field of wastewater treatment, and discloses a preparation method of an activated carbon-containing adsorption material and application of the activated carbon-containing adsorption material in wastewater treatment.The preparation method comprises the steps that modified phenolic resin, activated carbon and sulfo chitosan are added into a double-screw extruder, and melt extrusion is performed to obtain the activated carbon-containing adsorption material; the phenolic resin is high in phenolic hydroxyl content and strong in hydrophilicity, has a good adsorption effect on chromium ions, lead ions and other heavy metal ions in wastewater, and has good adsorption energy on the heavy metal ions due to the coordination and hydrogen-bond interaction of amido in the phenolic resin, and flocculation is achieved through synergism; a sulfonic acid group and chromium ions, lead ions and other heavy metal ions in the wastewater are subjected to a complexation reaction to form tiny flocs, the tiny flocs and quaternary ammonium salt groups are electrically neutralized to form precipitates, the heavy metal ions are effectively removed, and the flocculation effect is achieved; meanwhile, chitosan is a natural antibacterial agent, and forms an antibacterial system with a quaternary ammonium salt group and a sulfonic acid group to achieve a synergistic antibacterial effect.

The invention discloses a preparation method of a polydopamine modified biochar loaded Fe-Cu sodium alginate microsphere, which comprises the following steps: preparing biochar, modifying the biochar by using polydopamine, then loading the polydopamine modified biochar by using Fe-Cu, and finally obtaining the polydopamine modified biochar loaded Fe-Cu sodium alginate microsphere. According to the preparation method, the sodium alginate microspheres with different particle sizes can be prepared, the prepared sodium alginate microspheres have the function of adsorbing ammonia nitrogen, nitrate nitrogen, chlorobenzene, phosphorus, chromium ions and lead ions, the sodium alginate microspheres are used as the inner core to prepare anaerobic ammonia oxidation granular sludge, large density and good morphological support are provided for sludge particles, the problem of sludge bulking is avoided, and the anaerobic ammonia oxidation granular sludge can be prepared by using the sodium alginate microspheres as the inner core. The sewage treatment agent has the advantages that the settling performance is improved, the adsorption capacity on organic matters, ammonia nitrogen and heavy metals is enhanced, the sewage treatment effect is improved, and meanwhile, the sewage treatment agent is a biodegradable material and does not cause secondary pollution in the use process.

The invention discloses a flow battery electrolyte, preparation thereof and a flow battery. The electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, the positive electrode electrolyte contains vanadium ions, the negative electrode electrolyte contains titanium ions and chromium ions, and both the positive electrode electrolyte and the negative electrode electrolyte contain acid and compounds containing sulfonic acid groups. The preparation method of the electrolyte comprises the following steps: mixing acid and a sulfonic acid group-containing compound to obtain a solvent, dissolving a vanadium compound by adopting the solvent, and filtering to obtain first filtrate; adjusting the average valence state of vanadium ions to be 4, filtering and taking filtrate to obtain a positive electrode electrolyte; dissolving a titanium compound and a chromium compound by adopting the solvent, and filtering to obtain a second filtrate; and adding water into the second filtrate, and adjusting the concentrations of titanium ions and chromium ions to obtain the negative electrode electrolyte. The electrolyte, a positive electrode, an ion conduction membrane and a negative electrode are further assembled into the flow battery. The electrolyte and the flow battery have the characteristics of high energy density and low cost.

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 relates to the technical field of sewage treatment, and discloses an acidic sewage treatment agent and a preparation method thereof.Chitosan, triazinyl modified bentonite, cyclodextrin modified phenolic resin and polyacrylamide are added into a stirrer and stirred, and the acidic sewage treatment agent is obtained after stirring is finished. Cyclodextrin contained in the cyclodextrin modified phenolic resin has a unique cavity structure, and the cyclodextrin can adsorb heavy metal ions in sewage through the hydrophobic effect in a cavity and the coordination effect of hydroxyl functional groups on the outer side; wherein the phenolic resin is relatively high in phenolic hydroxyl group content and strong in hydrophilicity, and has a relatively good adsorption effect on chromium ions and lead ions in wastewater; the contained triazinyl and bentonite can be used for removing heavy metal ions; and the contained quaternary ammonium salt can also remove heavy metal ions in the sewage through complexation.

The invention relates to the technical field of wastewater treatment, in particular to a process and device for separating and recycling chromium and lead ions in wastewater, the device comprises a flotation sedimentation tank provided with a water inlet pipe and a water outlet pipe, a feeding mechanism and a dispersing mechanism, the flotation sedimentation tank is used for containing wastewater to be treated, and the feeding mechanism is arranged in the flotation sedimentation tank; the feeding mechanism is connected with the flotation sedimentation tank and used for injecting reactants, collecting agents and aeration gas into the flotation sedimentation tank, and the dispersing mechanism is connected with the feeding mechanism and used for dispersing the reactants, the collecting agents and the aeration gas into the flotation sedimentation tank to make full contact with wastewater. The process comprises the following steps: introducing a reactant into the wastewater, so that chromium ions and lead ions respectively react to generate a chromium precipitate and a lead precipitate; a collecting agent is introduced into the wastewater, so that the lead precipitate is combined with the collecting agent to obtain hydrophobicity; aerating the wastewater to enable the lead precipitate to form floating foam; and separating and recovering the floating foam and the chromium precipitate. The method can realize synchronous separation and recovery of chromium and lead ions in wastewater, and is high in separation rate and recovery rate.

The invention relates to an electrolyte precursor of an iron-chromium flow battery, an electrolyte, a preparation method and an application. The electrolyte precursor comprises a basic electrolyte and a stabilizer; the stabilizer comprises an indium-containing compound and amino acid. According to the electrolyte precursor of the iron-chromium flow battery, provided by the invention, the combination of the indium-containing compound and the amino acid is used as a stabilizer of the electrolyte, and under the synergistic matching condition of the indium-containing compound, the amino acid and chromium ions can be subjected to complex reaction, so that the inactivated hydrated chromium ions are converted into active chromium ions, and the chromium ions are converted into active chromium ions. Therefore, the reaction activity of the electrolyte is improved, and the cycling stability of the electrolyte is improved.

The invention belongs to the technical field of flow batteries, particularly relates to the technical field of flow batteries, and particularly relates to an electrolyte for a chromium-cerium flow battery as well as a preparation method and application of the electrolyte. The electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, the positive electrode electrolyte and the negative electrode electrolyte are both acidic aqueous solutions, the positive electrode electrolyte contains cerium (III) ions, and the negative electrode electrolyte contains chromium (III) ions. The cost of the electrolyte is lower than that of an existing redox flow battery, and the battery based on the electrolyte is high in voltage and good in cycling stability.

The invention belongs to the technical field of catalyst preparation, and particularly relates to a catalyst special for tetrachloropropane dehydrochlorination and a preparation method and application thereof. The preparation method of the catalyst comprises the following steps: (1) placing gamma-alumina powder in a solvent, adding an amino-containing silane coupling agent, and heating for reaction to obtain modified gamma-alumina powder; and (2) preparing modified gamma-alumina powder loaded with trivalent iron salt or trivalent chromium salt, and drying to obtain the special catalyst for dehydrochlorination of tetrachloropropane. Iron ions or chromium ions complexed by an amino silane coupling agent improve the stability of the active component, the active component is attached to a gamma-alumina matrix by the catalyst, the activity of the main catalyst can be effectively regulated and controlled, the phenomena of chlorine absorption, coking and the like are reduced, the dehydrochlorination reaction is carried out when tetrachloropropane is in contact with the solid matrix, and the dehydrochlorination reaction is carried out when the tetrachloropropane is in contact with the solid matrix. On the basis of high conversion rate and selectivity, side reaction is avoided.

The invention discloses a porous coordination polymer tanning agent and a preparation method and application thereof, and belongs to the technical field of leather tanning agents. According to the preparation method disclosed by the invention, a metal salt solution and an organic ligand solution are used as raw materials, and the porous coordination polymer tanning agent is prepared through calcination activation treatment; according to the method, dependence on an expensive organic solvent is avoided, the synthesis condition is changed from high temperature and high pressure to room temperature and normal pressure, energy consumption is reduced, and the risk of environmental pollution is remarkably reduced; meanwhile, the use of chromium ions is avoided, the reaction conditions of the porous coordination polymer tanning agent are moderated, and the organic solvent is removed, so that the pollution to the environment and the potential threat to the human health in the preparation process and the application process of the tanning agent are effectively reduced, and the requirement of large-scale production can be met.

The invention provides a porphyrin bimetal organic framework fluorescent probe, a preparation method and application of the porphyrin bimetal organic framework fluorescent probe in trivalent chromium ion detection. According to the preparation method, 5, 10, 15, 20-tetra (4-carboxyl phenyl) porphyrin and 2-amino terephthalic acid react with europium chloride hexahydrate and terbium chloride hexahydrate, so that the bimetal organic framework fluorescent probe is obtained. The fluorescent probe can be used for detecting Cr < 3 + > in water, and the detection limit is as low as 10.83 nM, so that the fluorescent probe can be used for rapid, high-sensitivity and high-selectivity detection of Cr < 3 + >.

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 provides a chromium-containing wastewater treatment device, and relates to the technical field of heavy metal ion treatment. The chromium-containing wastewater treatment device comprises a container body, a film, a water inlet pipe, a water outlet pipe, a light reducing agent pipe and a light source, the film is arranged in the container body and divides an inner cavity of the container body into a first cavity and a second cavity; the water inlet pipe, the water outlet pipe and the light reducing agent pipe are connected with the container body, a pipe cavity of the water inlet pipe is communicated with one end of the first cavity, a pipe cavity of the water outlet pipe is communicated with the other end of the first cavity, and a pipe cavity of the light reducing agent pipe is communicated with the second cavity; the light source is arranged in the second cavity; wherein hexavalent chromium ions and trivalent chromium ions can pass through the thin film, and the thin film can intercept the light reducing agent. The device adopts an integrated design, treats hexavalent chromium ions by utilizing a photo-reduction reaction, is more convenient to operate, greatly reduces the treatment period of wastewater containing hexavalent chromium ions, is higher in treatment efficiency, simple in structure, easy to mount and maintain and small in occupied area.

The invention relates to an iron-chromium flow battery electrolyte, a preparation method thereof and an iron-chromium flow battery. The iron-chromium flow battery electrolyte comprises a trivalent chromium ion organic complex, ferrous ions, hydrogen ions, lithium ions, metal ions except lithium, iron and chromium, and a solvent. An organic ligand in the trivalent chromium ion organic complex comprises a compound containing a carboxylic acid group and / or a compound containing an amino group. According to the iron-chromium flow battery electrolyte disclosed by the invention, the organic ligand and the trivalent chromium ions are complexed, and the catalytic action of the lithium ions and other metal ions except lithium, iron and chromium is combined, so that the reaction activity of chromium couple in the negative electrode electrolyte can be remarkably improved, the phenomenon that a large amount of trivalent chromium ions are aged is improved, the hydrogen evolution side reaction is reduced, and the service life of the iron-chromium flow battery is prolonged. And the charge-discharge capacity, the cycle stability and the energy efficiency of the iron-chromium flow battery are comprehensively improved, so that the purpose of high-efficiency operation of the iron-chromium flow battery is achieved.

The utility model discloses an industrial chromium-containing wastewater treatment device which comprises a reduction reaction tank, the right end of the reduction reaction tank is connected with the neutralization reaction tank, the right end of the neutralization reaction tank is connected with the coagulation reaction tank, and the right end of the coagulation reaction tank is connected with the inclined tube sedimentation tank. The method comprises the following steps: adding sodium hydroxide into trivalent chromium ions to generate indissolvable chromic hydroxide, firstly adding a polyacrylamide flocculant to generate relatively large muddy alum, then adding polyaluminum chloride to settle, settling in an inclined tube settling zone in an inclined tube settling tank, enabling settled sewage to enter a clean water tank, and when the chromium content detected by an online heavy metal monitor is lower than 0.5 mg / L, discharging the sewage from the clean water tank. The industrial wastewater meeting the standard is discharged, and the device is compact in structure, small in occupied area, convenient to operate, high in treatment efficiency, low in treatment cost and easy to popularize.

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 present disclosure relates to the technical field of metal surface treatment, and particularly relates to an electroplating additive for chromium-nickel alloy, a preparation method thereof, and an application thereof. The electroplating additive is selected from organic compounds whose molecular structures satisfy the following conditions: including at least one aryl group, cycloalkyl group, heterocyclic group or heteroaryl group; including at least one amino group, and the amino group is connected to the aryl group, cycloalkyl group, heterocyclic group or heteroaryl group; including at least two carboxyl groups, and the carboxyl groups are connected to the aryl group, cycloalkyl group, heterocyclic group or heteroaryl group. The present disclosure prepares an electroplating additive compound that helps deposit chromium ions and nickel ions during the electroplating process.

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 relates to the technical field of metal surface treatment, in particular to a chromium-nickel alloy electroplating additive and a preparation method and application thereof. The electroplating additive is selected from organic compounds with molecular structures meeting the following conditions: at least one aryl group, cycloalkyl group, heterocyclic group or heteroaryl group; the amino group contains at least one amino group, and the amino group is connected with the aryl group, the cycloalkyl group, the heterocyclic group or the heteroaryl group; the carboxyl group contains at least two carboxyl groups, and the carboxyl groups are connected with the aryl group, the cycloalkyl group, the heterocyclic group or the heteroaryl group. The present disclosure prepares a plating additive compound that facilitates deposition of chromium ions and nickel ions during plating.

The present invention belongs to the technical field of water pollution remediation, and particularly relates to a method for removing heavy metal pollutant chromium in water by using capacitive deionization technology, which comprises the following steps: clarifying the amount of raw water and the presence of chromium ions; adjusting the pH of the chromium-containing wastewater so that the chromium ions exist in an ideal form convenient for treatment; the chromium-containing wastewater enters a flow electrode membrane capacitive deionization device through a peristaltic pump, and after charging, a uniform electric field will be generated between the two electrode plates, and the target chromium ions will be enriched in this area; the voltage is set to be greater than the electrolysis voltage of water, and the adsorption and desorption processes are carried out simultaneously, and the desorption of the electrode will enrich the chromium ions in the flow electrode slurry, so as to achieve the purpose of chromium removal. The method of the present invention can well break through the voltage limitation, and at the same time utilize the Faraday reaction and the electrolysis reaction, simplify the operation steps of electrode regeneration, and achieve efficient removal of heavy metal pollutant chromium in water.

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 invention discloses a method for simultaneously detecting copper ions and chromium ions based on double-emission center carbon dots. Comprising the following steps: (a) pretreating a sample to obtain copper and chromium ion liquid to be detected; (b) synthesizing rhizoma anemarrhenae fluorescent carbon dots (AB-CDs); (c) synthesizing Pu'er tea fluorescent carbon dots (PT-CDs); (d) uniformly mixing the AB-CDs solution and the PT-CDs solution to prepare a dual-emission center carbon dot (AP-CDs), namely the ratio fluorescent probe; and (e) mixing the copper ion solution to be detected, the AP-CDs solution and the ascorbic acid (AA) solution, adjusting the pH value to 4.78, incubating for 40 minutes, detecting under the excitation wavelength of 365 nm, recording a fluorescence emission spectrum in a range of 385-710 nm to obtain fluorescence intensity values at 440 nm and 670 nm, and calculating the copper ion content by combining the standard curve. And mixing a to-be-detected chromium ion solution with the AP-CDs solution, adjusting the pH value to 4.78, detecting under the excitation wavelength of 365 nm, recording a fluorescence emission spectrum in a range of 385-710 nm to obtain fluorescence intensity values at 440 nm and 670 nm, and calculating the chromium ion content by combining with the standard curve. The detection method has the advantages of high selectivity and high sensitivity, and is simple to operate, obvious in phenomenon and good in repeatability.

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.