191 results about "Chromium contamination" patented technology

Electrode materials systems for planar solid oxide fuel cells with high electrochemical performance including anode materials that provide exceptional long-term durability when used in reducing gases and cathode materials that provide exceptional long-term durability when used in oxygen-containing gases. The cathode materials comprise zinc-doped lanthanum strontium ferrite (LSZF) or an alternative ferrite, cobaltite or nickelate ceramic electrode material. The cathode material also may comprise a mixed-conducting ceria-based electrolyte material, a palladium dopant, or a combination of these. The cathode may have a bi-layer structure. A ceramic-based interfacial layer may be provided at the electrolyte/cathode interface. The multilayer cathode system and its palladium doped cathode material exhibit a high degree of tolerance to chromium contamination during operation with metallic interconnect materials.

The invention discloses a layered remediation method for chromium contaminated soil. The method comprises the following steps: detecting the actual chromium contamination condition of soil, determining the boundary of severe and mild chromium contaminated soil on soil depth, performing remediation on the severe chromium contaminated soil by adopting a chemical reduction stabilization method, performing remediation on the mild chromium contaminated soil by adopting a chemical or biochemical reduction stabilization method, performing soil conservation, balancing the soil acidity and alkalinity and performing later-stage tracking and monitoring. An actual chromium contaminated field serves as a support, the combined remediation methods are selected aiming at the current situation that the contamination degrees of the upper soil and the bottom soil are different, the severe chromium contaminated soil on the surface layer is subjected to remediation by adopting the chemical reduction stabilization method, the mild chromium contaminated soil on the deep layer is subjected to remediation by adopting the chemical or biochemical reduction stabilization method, the defects that the soil properties are not distinguished and a same remediation method is adopted in a unified mode in the previous research are overcome, and ex-situ remediation and in-situ remediation are combined to be used, so that the remediation method is reasonable in application under the condition that the remediation effect is guaranteed, the remediation cost is reduced, and the method can be applied to actual soil remediation on a large scale.

The invention discloses preparation and an application for a heavy metal chromium contaminated soil remediation material. Preparation for biological carbon particles comprises the following steps: 1) cleaning, drying and crushing agriculture waste to obtain a substance A; and 2) placing the substance A under a protective atmosphere to deoxidize and carbonize, and grinding and sieving carbonize products to obtain the biological carbon particles. Preparation for supported type nano zero-valent iron particles comprises the following steps: 1) preparing ferrite into a solution; 2) adding biological carbon particles into the solution, and uniformly mixing the biological carbon particles with the solution; and 3) dissolving a reducing agent into a solvent to obtain a mixture, adding the mixture into the system in the last step under the protective atmosphere, stirring the mixture, sufficiently reacting the mixture, separating nano zero-valent iron, washing, drying and grinding the nano zero-valent iron to obtain the supported type nano zero-valent iron particles. The invention further discloses the application of the supported type nano zero-valent iron particles to remediating chromium contaminated soil in situ. The in-situ remediation method for the heavy metal chromium contaminated soil comprises the following steps: adding the supported type nano zero-valent iron particles into soil, uniformly mixing the supported type nano zero-valent iron particles, adding deoxygenated water, and carrying out remediation. The remediation material prepared by the preparation disclosed by the invention is high in efficiency of remediating the chromium contaminated soil, and capable of improving the soil structure and improving the soil fertility.

The invention belongs to the technical field of contaminated soil repairing treatment, and particularly relates to a heavy metal (chromium VI)-contaminated soil different-position chemical leaching repairing technology and device. The chromium-contaminated soil different-position leaching repairing device comprises a one-level scrubbing unit, a two-level scrubbing unit, a waste liquid treatment unit and a medicament adding unit. The one-level scrubbing unit comprises a pulper, an even mixing and homogenizing device, a one-level vibration screen and a one-level cyclone. The two-level scrubbing unit comprises a strong stirrer, a two-level cyclone and a two-level vibration screen. The waste liquid treatment unit comprises a thickener, a to-be-pressed mud tank and a plate-and-frame filter press. The medicament adding unit comprises a medicament tank. The chromium contaminated soil different-position leaching repairing technology comprises one-level leaching, two-level leaching and waste liquid treatment. The different-position leaching repairing technology can be flexibly adjusted according to the situation of soil or bottom mud containing various pollutants. The different-position leaching repairing technology device can be moved to a next project site to be used again after the project is over, and therefore the equipment utilization rate can be increased, and cost can be reduced.

The invention discloses a repair method of chromium-contaminated soil, which belongs to the technical field of environment engineering. The method comprises the following steps: reducing hexavalent chromium in the chromium-contaminated soil, removing trivalent chromium and performing sewage treatment. Ferrous sulfate is added into the chromium-contaminated soil, and the reaction environment is adjusted, so that the efficiency for reducing the hexavalent chromium in the chromium-contaminated soil into the trivalent chromium is improved, and conditions are provided for removing chromium; chromium in the soil is extracted by adopting disodium ethylenediamine tetraacetate, the removal rate of the chromium in the soil is increased by adopting microwave heating, and the reaction time is shortened; sodium sulphide is added into chromium sewage, and the reaction environment is adjusted, so that the settling efficiency of heavy metals in the sewage is improved; and additionally, the sewage is converted into disodium ethylenediamine tetraacetate solution, so that resource recovery and utilization are realized. According to the method, the hexavalent chromium is converted into the trivalent chromium to be treated, so that the environmental risk in the repair process is reduced; the chromium-contaminated soil is converted into chromium sewage for treatment, so that the treatment efficiency is improved, and the treatment effect is guaranteed; and the method has the characteristics of no secondary pollution, high efficiency, rapidity, high resource utilization rate and the like.

The invention discloses a preparation method for extracting green synthesis nanometer zero-valent iron through shaddock peels and application. According to the preparation method, a shaddock peel extracting solution is used as a reducing agent, reduced ferric ions or divalent ferrous ions are used as a nano-iron based material, and a green remediation material, namely, green synthesis nano-iron particles, of chromium contaminated water is prepared and obtained. The method is low in energy consumption and cost, environment-friendly, simple in process and convenient to operate, the obtained green synthesis nanometer zero-valent iron is good in stability, and the removal rate on chromium contamination in waste water is high. The surface of the material is coated with some organic substances in the extracting solution, is prevented from being in direct contact with air and is not prone to being oxidized. Cr(VI) can be fast reduced into Cr(III), finally Cr(III) removal is achieved in the form of insoluble hydroxide (Cr(OH)3 and/or FexCr1-x(OH)3) sediment, no toxic substance is separated out, and not secondary contamination is generated.

The invention discloses a hexavalent chromium contaminated soil in-situ remediation method. The method comprises the following steps: dissolving a water-soluble sulfur-containing reagent into water, preparing 0.1-10 percent of a reducing agent, mixing chromium contaminated soil and the reducing agent in a reactor according to a mass ratio of the soil to the reducing agent being 3:1-1:5, stirring for 0.5-2 hours, and drying. Then, a stabilizer is added for treatment, so that the soil meets the environmental risk control requirement. The hexavalent chromium which is high in toxicity and easy to migrate and can be absorbed and utilized by plants in the soil is completely reduced and immobilized into trivalent chromium which is low in toxicity and difficult to migrate and can be utilized by plants, and bounce is difficultly caused. The in-situ remediation of the heavy metal hexavalent chromium contaminated soil is realized.

The invention discloses a preparation method of an in-situ repair material for soil polluted by heavy metal chromium and an application of the material. According to the invention, the in-situ repair material, which is modified nano metal particles, for the soil polluted by chromium is prepared by taking steel pickling waste liquor as a raw material and carboxymethylcellulose as a dispersing agent; the material has the advantages of good mobility, great specific surface area and strong stability and has good reaction activity in the in-situ repair of the soil polluted by the chromium and better repair effect than common nano zero-valent iron; as the preparation method is simple, the in-situ repair material can be prepared in the site and used for implementing the in-situ repair of the soil polluted by the chromium; and meanwhile, the steel pickling waste liquor is used for preparing the zero-valent iron, so that the treatment cost can be reduced and the purpose of treating waste by using waste is achieved.

The invention discloses a bacterial strain Pannonibacterphragmitetus BB for repairing a chromium slag contaminated site, which has the preserved number of CGMCC No. 3052. The inventor collects contaminated soil of a chromium slag scrapyard in a Hunan ferroalloy work to obtain the bacterial strain with the hexavalent chromium reducing characteristic through screening, separation and acclimatization. The bacterial strain has the function of reducing the hexavalent chromium to trivalent chromium, is used for treating chromium contamination, and has low cost and simple operation.

The invention belongs to the technical field of environment protection, and relates to a remediating technology for chromium-contaminated soil, in particular to a reduction-stabilization two-stage type remediating method for the chromium-contaminated soil. The method sequentially comprises the following steps that (1) after a chromium reducing agent and the chromium-contaminated soil are evenly mixed, the humidity of the soil is adjusted to 20%-40%, chromium in the soil and the chromium reducing agent fully react for 0.5-5 days, and the content of Cr (VI) in the soil is lowered to below 150 mg/kg, namely remediation of the reduction stage is completed; and (2) chromium stabilizing agents are added into the contaminated soil after reduction through the step (1), the chromium stabilizing agents and the soil are evenly mixed, the humidity of the soil is still kept at 20%-40%, and the soil is stabilized for 15-60 days, namely the stabilization stage of the chromium-contaminated soil is completed. By means of the method, the toxicity of the chromium can be lowered, and the total leaching concentration of the chromium in the soil is greatly lowered; the method can be used for ex-site remediation and in-site remediation, and is a rapid and efficient chromium-contaminated soil remediating method.

The invention relates to a method by utilizing sludge in a sewage plant to treat the pollution of chromium. The method comprises the steps of proportioning sludge discharged from a sewage treatment plant and hexavalent chromium pollutant, crushing, mixing, agitating, allowing detoxification reaction, and treating the pollution of hexavalent chromium. The method can be used for treating dregs of the chromium, restoring a chromium pollution site after the chromium pollution site is removed, and treating the polluted soil of the hexavalent chromium. The method of the invention utilizes waste to treat the waste, and is simple and feasible.

The invention relates to an ex-situ sorting, cleaning and repairing device for chromium-polluted soil and a cleaning and repairing technology using the ex-situ sorting, cleaning and repairing device. The ex-situ sorting, cleaning and repairing device comprises a raw material treatment unit, a first-level oversize particle treatment unit, a first-level undersize liquid treatment unit, a second-level undersize liquid treatment unit, a waste liquid collecting unit, a waste liquid treatment unit, a cleaning liquid adding unit and a chemical adding unit. The cleaning and repairing technology for conducting ex-situ sorting and cleaning on the chromium-polluted soil through the device comprises the steps of pulping, soil particle classification, cleaning of soil particles different in level and waste liquid treatment. The whole technology process is simple, equipment is easy to machine, the publicly known equipment can be adopted, the cost is low, the occupied space is small, continuous operation can be conducted, and energy consumption is low. The removal rate for hexavalent chromium in the soil can reach 95% or above, the residue concentration of the hexavalent chromium is lower than 50 mg/kg, and influences of the chromium on the soil, underground water and the surrounding environment are removed.

The invention relates to a wet detoxification method for chromium slag and chromium-containing pollutants. The wet detoxification method comprises the following steps: screening and crushing the chromium slag and the chromium-containing pollutants, performing wet milling on the chromium slag and the chromium-containing pollutants in a ball mill, adding a filtrate containing sulfate ions, leaching out acid-soluble calcium chromate in chromium slag slurry, adding the chromium slag slurry and a first reducing agent sequentially into a reaction tank, stirring and mixing the chromium slag slurry with the first reducing agent to perform reduction reaction, reducing the acid-soluble calcium chromate in chromium slag slurry to trivalent chromium, adding concentrated sulfuric acid and to stirring and mixing for regulating, adjusting pH value of the chromium slag slurry to be 7+/-0.5, then adding a second reducing agent into the reaction tank and stirring and mixing for reducing, stirring the reduced slag slurry to cure the reduced slag slurry, and converting hexavalent chromium in the chromium slag slurry to chromic hydroxide sediment; and separating solid and liquid of the cured chromium slag slurry. The wet detoxification method has the characteristics of low cost, no waste liquid, no slag returning phenomenon, good detoxification effect and capability of being applicable to the large-scale industrial production.

The invention belongs to the technical field of environmental microorganisms, and particularly relates to Intrasporangiaceae sp Q5-1 with reduction effect on hexavalent chromium and application of the Intrasporangiaceae sp Q5-1 in the purification of chromium pollution in wastewater. The invention is characterized in that the Intrasporangiaceae sp Q5-1 which has reduction effect on the hexavalent chromium is obtained through the separation from manganese mine soil in Hunan province. The strain can reduce the hexavalent chromium in wastewater containing chromium into trivalent chromium, which greatly reduces the toxicity of the chromium in the wastewater. The strain is named the Intrasporangiaceae sp Q5-1, and is a newly discovered chromium-reducing bacterium, and CCTCC NO of the strain is M208239. The preliminary study shows that the strain has better application prospect in the treatment of the chromium pollution in the wastewater.

The invention belongs to the field of repairing soil heavy metal pollution, and discloses a preparation method of a reducing agent for removing chromium-contaminated soil, and a method for repairing chromium-contaminated soil by using the reducing agent under microwave-assisted conditions. The reducing agent includes: activated carbon powder, 40mg/L of Mn ²⁺ liquid. The steps of the method for remediating polluted soil include: mixing the sieved chromium-contaminated soil with the reducing agent described in the present invention, and treating it with microwave radiation for a period of time to complete the remediation of the chromium-contaminated soil. The invention can greatly reduce the restoration time of the polluted soil, realize the removal of the heavy metal chromium in the polluted soil within a few minutes, and can meet the requirement of rapid restoration of the heavy metal polluted site.

A method for preparing active slag powder by utilizing chromium slag and chromium sludge employs chromium slag, chromium sludge, waste, gypsum, waste stone powder and a carbon-base substance as raw materials, performing material preparation, mixing and homogenization, shaping, and reduction roasting and quenching, adding an alcohol amine type auxiliary agent and gypsum ingredient, or adding an alcohol amine type auxiliary agent, modified bentonite and gypsum ingredient, and together grinding to form the active slag powder with the fineness of 80 mu m and the screening tailings content of 18% or less. The method is simple in technology, small in investment, large in resource utilization amount, and free of secondary pollution or potential pollution trouble, also is capable of simultaneously recycling, decomposing and receiving chromium slag, chromium-polluted soil and other wastes, is thorough in detoxifying processing and relatively low in utilization cost, and realizes ultimate resource processing utilization.

The invention discloses a remediation method of chromium-contaminated soil. The method comprises the following steps: (1), detecting the chromium contamination condition of soil, and determining a concentration distribution rule of hexavalent chromium in the chromium-contaminated soil; (2), with the soil layer depth with the hexavalent chromium transverse concentration distribution of 800-1300mg/kg as a boundary, distinguishing severe chromium-polluted soil from mild chromium-polluted risky soil; (3), stripping the severe chromium-contaminated soil, performing ex-situ remediation on the severechromium-contaminated soil, and performing in-situ remediation on the risky soil; (4), backfilling the remediated severely chromium-contaminated soil onto the remediated risky soil, adding humic acid, performing plowing, and planting plants capable of enriching chromium; (5), regularly harvesting, removing and reseeding plants capable of enriching chromium, and detecting the total chromium content above the boundary for at least 6 months; and (6), determining that the concentration of hexavalent chromium on the surface soil of the chromium-contaminated soil meets the restoration target concentration, and if the detection result is unstable, repeating the (5) until the detection concentration reaches the standard.

An oxidation resistant fuel cell component and a method for creating an aluminum diffusion surface layer within a fuel cell component to reduce chromium contamination occurring during operation of a fuel cell are disclosed. Generally, an aluminum-containing slurry may be applied to the fuel cell component. The component may then be heated to diffuse aluminum into the component and to form an aluminum diffusion surface layer therein. The surface layer may be characterized by an intermetallic aluminum-containing phase extending below the surface of the fuel cell component.

The invention discloses a modified nano zero-valent iron-bio-based composite functional material as well as a preparation method and an application thereof. The modified nano zero-valent iron-bio-based composite functional material comprises vulcanized nano zero-valent iron and a bio-based material, and the bio-based material is used as an adsorption carrier to load the vulcanized nano zero-valent iron; wherein the bio-based material comprises carbon microspheres and calcium alginate; and the vulcanized nano zero-valent iron is prepared from the following raw materials: ferric chloride hexahydrate and a vulcanizing agent. In the preparation process of the modified nano zero-valent iron-bio-based ternary composite material, vulcanized nano zero-valent iron is synthesized by utilizing a one-step method and is loaded on the surfaces of the carbon microspheres and the calcium alginate carrier, and solid loading and calcium alginate loading are combined; the sulfurized nano zero-valent iron material has larger specific surface area, high-efficiency adsorption performance, reduction performance and recovery potential, and can achieve the purpose of efficiently fixing cadmium and chromium pollution at the same time.

The invention discloses a method for compounding a nano ceramic silane composite film before spraying an aluminum product. The composite film uses a sol-gel technology, is treated by a nano SiO2 silane treatment fluid and dewatered to form a three-dimensional network structure on the basis of an Si-O-Si bond, and is compounded with the surface of the aluminum product on the basis of an Si-O-Al covalent bond. Since the nano ceramic silane composite film is subjected to chromium-free treatment, the invention solves the problem of chromium pollution in aluminum product industry. No substance affecting the film formation is generated in the surface treatment process and attached to the surface of the aluminum product, so the aluminum product does not need to be washed with water before spraying. The added nano filler is dispersed in the network-structure film layer, and can form a bridge bond on the surface of the aluminum product after being compounded with hydrolyzed silane, so that the film is tightly combined with the aluminum product without any crack; and the film is compounded with the aluminum product in a combination mode of chemical covalent bond, thereby obviously increasing the adhesive force of the coating.

The invention relates to a rinsing agent for restoring heavy metal chromium polluted soil, which has the advantages of higher biodegradability and higher rinsing efficiency. The rinsing agent is prepared by the following steps: accurately weighing 1.00g of chromium polluted soil sample, adding a 10-70% PESA (polyepoxysuccinic acid) solution in a solid-to-liquid ratio of 1:25, oscillating at room temperature, standing, centrifugating and filtering to complete the rinsing process, wherein the oscillation time is 12 hours, the standing time is 12 hours, the centrifugating speed is 4000 r/min, and the centrifugating time is 20 minutes. The chromium concentration of the polluted soil is 600-2300 mg.kg<-1>. By using the PESA for reinforced restoration of the chromium polluted soil, the method has the characteristics of high restoration efficiency, high operability, low environmental risk and the like.

The invention relates to a method for restoring chromium contaminated soil through EDTMPA (ethylenediamine tetra methylenephosphonic acid), and the method has strong biodegradability and high leaching efficiency. The method comprises the following steps: accurately weighing 1.00 g of chromium contaminated soil sample, adding EDTMPA solution with the concentration of 1-22% according to a solid-to-liquid ratio of 1:25, and oscillating, stewing, centrifuging and filtering at room temperature to finish the leaching process, wherein the oscillating time is 12 hours, and the stewing time is 12 hours; the centrifugal rotating speed is 4,000 r/min, and the centrifuging time is 20 minutes; the concentration of the chromium polluted soil is 600-2,300 mg.kg<-1>. The measure of forcefully restoring the chromium contaminated soil by EDTMPA is adopted in the invention, and the method has the advantages of high restoring efficiency, strong operability, low environmental risk, and the like.

The invention relates to the technical field of soil treatment, in particular to a resource utilization method of hexavalent chromium contaminated soil. The method comprises the following steps: (1) physically crushing and screening hexavalent chromium contaminated soil, (2) physically crushing and screening blast furnace slag, (3) uniformly stirring and mixing water, the screened hexavalent chromium contaminated soil and blast furnace slag, (4) granulating the mixture to form a ceramsite raw material, (5) drying and roasting the ceramsite raw material, and (6) cooling the roasted ceramsite toobtain a ceramsite product taking hexavalent chromium contaminated soil and blast furnace slag as raw materials. According to the method, the remediation problem of the remediated soil is solved in aresource utilization mode, resources such as raw coal do not need to be purchased additionally, the purpose of treating waste with waste is achieved, and the disposal cost is reduced.

The invention discloses a method for the in-situ remediation of heavy metal hexavalent chromium-contaminated soil. According to the method, by using the advantages of a microbial fuel cell (MFC), an anode assembly and a cathode assembly (a diaphragm is arranged between the anode assembly and the cathode assembly) is embedded in the contaminated soil, the anode assembly locally utilizes organic matters in the soil as fuel, generated electronics reach the cathode assembly by virtue of anodes and leads, heavy metal hexavalent chromium adsorbed on the cathode assembly is reduced, and thus the degradation and the transformation of heavy metal hexavalent chromium contaminants in the soil are promoted, and the in-situ remediation of the heavy metal hexavalent chromium-contaminated soil is realized. By adopting an in-situ remediation process, the method has the advantages of high removal efficiency, low cost, good safety, no need of ventilation and energy consumption, capability of recycling and no secondary pollution because the anode assembly and the cathode assembly can be combined and optimized according to the actual conditions, has the great importance in remediating the heavy metal hexavalent chromium-contaminated soil, has a wide application prospect in fields of resources and environments such as the remediation of the heavy metal hexavalent chromium-contaminated soil, and the like.

The invention relates to a method for preparing a chromium curing/stabilizing material, the chromium curing/stabilizing material prepared thereby and an application thereof. The method comprises the following steps of: uniformly mixing a silicon-aluminium mineral, calcium-magnesium mineral and an additive, and after high-temperature calcination at the temperature of 800-1600 DEG C, obtaining a calcinated material; then uniformly mixing the calcinated material, a stabilizer, a chromium precipitating agent and a viscosifier to obtain the chromium curing/stabilizing material. The chromium curing/stabilizing material can be used for curing/stabilizing chromium and controlling chromium pollution, and is especially used for remediation of soil polluted by the chromium.

The invention discloses an eluting agent used for remediation of chromium-contaminated soil, a remediation method and an apparatus. The eluting agent is an aqueous solution including the following components: citric acid, sodium dodecyl benzene sulfonate and a pH value conditioning agent, wherein a mol ratio of citric acid to sodium dodecyl benzene sulfonate is 0.05 to 0.5: 0.01-0.1 and the pH value of the eluting agent is 1 to 3. The ex-situ remediation method and in-situ remediation method can be used for remediation of the chromium-contaminated soil. The invention also provides the apparatus used for in-situ remediation. The eluting agent is easy to degrade, poses no secondary pollution to the environment, exerts small influence on the physical and chemical properties of the soil, has a total chromium removal rate of more than 90% and shows good removal effect on trivalent chromium; and chromium in eluted soil is mainly in a residual form, total chromium concentration in the eluted soil is lower than national soil environment standard III, and environmental harm is not posed.