28 results about "Zerovalent iron" patented technology

This invention discloses a method for the simultaneous preparation of micronized and stabilized zero-valent iron (ZVFe) based on ball milling with terephthalic acid, belonging to the field of groundwater pollution remediation materials. The method includes the following steps: 1) incorporating terephthalic acid into micron-sized ZVFe powder and mechanically ball milling it; 2) cleaning the material with a solvent and drying it to obtain micronized and stabilized ZVFe reducing material. This invention simultaneously achieves the micronization and stabilization of ZVFe. This method enhances the reducing activity, internal surface hydrophobicity, and electron selectivity of ZVFe materials, improves their reducing performance and electron selectivity for pollutants such as halogenated hydrocarbons and heavy metals, effectively inhibits the oxidative deactivation of ZVFe materials in the aquatic environment and the hydrogen evolution side reaction with water, enabling ZVFe materials to maintain high reducing activity stably in water for a long period. This invention solves the technical problems of poor stability and difficult storage of micronized ZVFe materials in water, which is beneficial for reducing material replacement frequency and resource consumption.

This invention relates to a modified zero-valent iron / biochar composite material with oxygen-rich vacancies and its application. The modified zero-valent iron / biochar composite material comprises a biochar carrier and zero-valent iron loaded on the biochar carrier. The surface of the zero-valent iron is coated with sulfur-containing iron compounds and / or boron-containing iron compounds, and the surface of the zero-valent iron contains abundant oxygen vacancies. The modified zero-valent iron / biochar composite material is specifically prepared by the following method: dispersing the biochar carrier and zero-valent iron in oxygen-free water and grinding; adding a sulfur source or boron source to the ground suspension, stirring and grinding thoroughly, and drying; subsequently soaking in a reducing solution, followed by high-temperature calcination and cooling to obtain the modified zero-valent iron / biochar composite material. Compared with the prior art, the modified zero-valent iron / biochar composite material prepared by this invention can be used synergistically with compound oxidants to achieve effective remediation of organically contaminated soil.

The application discloses a nano zero-valent iron modified hemicellulose biochar composite material and a preparation method and application thereof. The preparation method comprises the following steps: mixing xylan raw materials and iron oxide, performing ball milling treatment, and then performing a carbothermic reduction process in a microwave pyrolysis device under a nitrogen protection atmosphere and a constant temperature condition, so as to obtain the nano zero-valent iron modified hemicellulose biochar material after cooling. The composite material is prepared by using the above preparation method. The composite material is applied to purification treatment of polluted wastewater containing chlorinated hydrocarbons. The composite material has low raw material cost, simple preparation method, can form stable structure pores, has good adsorption performance and catalytic activity, realizes molecular dispersion of zero-valent iron in a hemicellulose biochar matrix, and improves adsorption and reduction capacity of the composite material on chlorinated hydrocarbon pollutants.

The application provides a phosphorus modified zero-valent iron catalytic material, a preparation method, a remediation agent and application. 3‑ The phosphorus modified zero-valent iron catalytic material is obtained, wherein the particle size of the zero-valent iron is micron level. The preparation method of the application can be completed in an air atmosphere, and does not need high temperature, vacuum or addition of toxic chemical reagents. The preparation process only involves physical mixing and mechanical ball milling, the equipment requirement is simple, the operation is convenient, the energy consumption is low, the dual benefits of environmental governance and ecological restoration are combined, and the green and sustainable development environmental governance concept is met.

The application provides a groundwater in-situ remediation system and method of multiple biological permeation reaction wall coupling ultrasonic waves and plant remediation, the groundwater in-situ remediation system comprises a multiple biological permeation reaction wall, a PLC control system and an artificial plant ecological remediation area, the multiple biological permeation reaction wall is arranged in a funnel-gate type engineering, the funnel part blocks the contaminated groundwater through a vertical cement curtain, an ultrasonic generator module is arranged in front of the gate part of the multiple biological permeation reaction wall, the multiple biological permeation reaction wall is divided into two layers, the filling material of the first layer permeation reaction wall is mainly composed of zero-valent iron, iron oxide and construction waste, the filling material of the second layer biological permeation reaction wall is mainly composed of high-performance biological adsorption zeolite and ORC slow-release material calcium peroxide, a microbial bacteria liquid injection pipe is arranged in the second layer biological permeation reaction wall, and monitoring wells are arranged on the two sides of the multiple biological permeation reaction wall and the artificial plant ecological remediation area.The application can treat and remediate multiple composite pollutants at a time, and the pollutant degradation efficiency is improved.

The utility model belongs to industrial wastewater treatment technical field discloses a kind of Fenton oxidation pond packing shelf and Fenton reaction pond device, including packing shelf body and at least two hanging material layers, and packing shelf body includes upper shelf body and lower shelf body, and both are detachably connected along vertical direction, and upper shelf body top is provided with lifting connection structure;At least two hanging material layers are respectively arranged on upper shelf body and lower shelf body, and each layer hanging material layer includes multiple hanging material cross beams that are arranged in parallel along horizontal interval, and multiple filter bags are detachably and interval hung along the length direction of each hanging material cross beam, and filter bag interior is filled with zero-valent iron reagent, and raw water in oxidation pond can contact reaction with zero-valent iron reagent in its interior through the small hole of filter bag.The utility model effectively improves the contact efficiency of reaction reagent, reduces ferrous sulfate consumption, makes reaction process more sufficient, accelerates reaction rate, improves treatment effect;Meanwhile, it is convenient to quickly replace and supplement reaction reagent on packing shelf, and operation is simple.

This invention discloses a low-temperature plasma-coupled, highly active, low-cost process for synthesizing ammonia using zero-valent iron, belonging to the field of ammonia synthesis technology. The process comprises: using a plasma reactor with hydrogen as a reducing agent to induce a plasma hydrogen reduction reaction in a Fe2O3 source to synthesize zero-valent iron; and using the synthesized zero-valent iron as a catalyst to induce a plasma ammonia synthesis reaction between H2 and N2 to produce ammonia. The plasma ammonia synthesis reaction is carried out at atmospheric pressure and a reaction temperature of 220-300℃. This invention, driven by low-temperature plasma, pioneers a cross-industry co-production process of "iron ore reduction-ammonia synthesis" in a single system. Specifically, it directly uses zero-valent iron obtained from the efficient reduction of iron ore by hydrogen-based plasma as a catalyst for low-temperature plasma ammonia synthesis. The overall process is simple, the synthesis conditions are mild, and the catalyst cost is low.

This invention relates to a carboxymethyl cellulose-modified nanomaterial of zero-valent iron, its preparation method, and its application in the remediation of trichloroethylene-contaminated water or groundwater. The material is prepared by mixing sodium carboxymethyl cellulose with a water-soluble ferrous salt in a deoxygenated aqueous phase, followed by reduction with an oxygen-free sodium borohydride aqueous solution under nitrogen protection. The sodium carboxymethyl cellulose forms a coating layer on the surface of the zero-valent iron through carboxylate groups, distributing the zero-valent iron particles on the carboxymethyl cellulose framework or the coating layer surface. Scanning electron microscopy analysis shows that the zero-valent iron particles are mainly distributed in the range of 80-150 nm; the zeta potential measured in anhydrous ethanol dispersion is -47 mV. The material is added at 0.5-5.0 g / L to trichloroethylene-contaminated water or groundwater and reacted under sealed, light-protected conditions at pH 6.0-8.0 and a temperature of 20-35°C for the reduction and dechlorination treatment of trichloroethylene.

This invention discloses a zoned permeable reactive barrier (PRB) for groundwater denitrification using a combination of zero-valent iron / slow-release carbon and zeolite, and its operating process. The PRB's structure comprises: (1) a quartz sand water distribution zone; (2) Fe... 0 / C-Denitrifying bacteria reaction zone; (3) Zeolite adsorption zone. This invention uses a mixture of biomass slow-release carbon and artificial slow-release carbon as a slow-release carbon source, and adds zero-valent iron to construct Fe 0 The / C system, using a mixed denitrifying bacteria agent for rapid start-up, and a zoned permeable reactive barrier (PRB) operation process for groundwater denitrification have been developed. This includes: filling processes based on different media permeability coefficients, reaction zone packing material compatibility based on different slow-release rates, and operating parameters based on different groundwater nitrogen pollutant concentrations. This invention improves the adaptability of the PRB process to hydrogeological conditions, accelerates the start-up of the denitrification process, ensures denitrification effectiveness during the start-up phase, improves denitrification efficiency during operation, and extends remediation time.

The application discloses a remediation method for heavy metal-organic compound contaminated soil, and belongs to the technical field of contaminated soil remediation. The method comprises the following steps: mixing the compound contaminated soil with iron modified biochar and zero-valent iron reducing agent, adding water step by step to obtain pretreated soil, placing the pretreated soil into a microwave reaction cavity for microwave irradiation treatment, transferring the soil to a turning machine after the irradiation is completed, and adding, in sequence, a persulfate oxidant, a sodium lignosulfonate aqueous solution, ferrous oxalate and a sodium dihydrogen phosphate aqueous solution after cooling, mixing by turning and placing for maintenance to obtain remediated soil. The iron modified biochar and the zero-valent iron are activated by microwave irradiation, combined with persulfate oxidation and phosphate precipitation fixation, efficient degradation of organic matter in the soil and stabilization of heavy metals are realized, and the method can be used for ex-situ remediation of heavy metal-organic compound contaminated soil.

This invention discloses a method for passivating lead ions and other heavy metals through a permeation process, belonging to the field of heavy metal pollution control technology. Addressing the problems of uneven penetration, poor stability, and low utilization rate of existing lead pollution passivation technologies, this invention first pre-treats the lead-containing contaminated medium to adjust its moisture content. Then, a composite passivating penetrant is prepared by compounding phosphates, sulfides, zero-valent iron powder, and nonionic surfactants. This penetrant is injected into the medium in two stages using high-pressure rotary jet spraying, followed by controlled pressure and volume and 10-14 days of moisture retention curing. This invention improves the uniformity and utilization rate of the agent penetration through synergistic agent action and a staged injection process. After treatment, the TCLP leaching concentration of lead ions is consistently below 5 mg / L. This method is suitable for lead-containing media such as contaminated soil, sediment, tailings, and smelting waste, exhibiting high passivation efficiency, strong stability, and environmental friendliness.

This invention provides a permeable reactive wall process and its application for simultaneously removing hexavalent uranium and sulfate from groundwater. The permeable reactive wall process consists of a first treatment unit and a second treatment unit arranged sequentially along the water flow direction. The first treatment unit is filled with a first reaction medium, including zero-valent iron, sulfur-modified coconut shell charcoal, and sulfate-reducing bacteria. The second treatment unit is filled with a second reaction medium, including zero-valent iron, ferric oxide, sulfur-modified coconut shell charcoal, and *Priestia* sp., a non-pathogenic and environmentally friendly bacterium that can simultaneously remove uranium from water through adsorption and reduction. The composite permeable reactive wall process provided by this invention has strong resistance to interference from other substances in the water. When used to simultaneously remove sulfate and hexavalent uranium from groundwater at 15–35°C, the removal rates of both sulfate and uranium in the groundwater are greater than or equal to 90%.

The application discloses a ball-milling mixed iron powder and a preparation method and application thereof. The mixed iron powder is prepared from iron powder, a solid oxidizing agent and a phenolic compound as raw materials. In a ball-milling condition, different valence iron species are generated in situ through a pre-oxidation effect of the solid oxidizing agent, self-depassivation is realized, and the passivation phenomenon generated by zero-valent iron in water is overcome. The mixed iron powder has high reactivity and can be used for wastewater treatment containing oxidizing components.

The present application belongs to the field of environmental management materials, and relates to a composite material for heavy metal pollutant remediation and a preparation method and application thereof. In the prior art, modified Shish Mine can remove arsenic and cadmium simultaneously, but the removal capacity for cadmium is still weak, and the single sulfur-modified zero-valent iron-based material has low reactivity and selectivity. The present application provides a composite material for heavy metal pollutant remediation, which comprises Shish Mine and sulfur-doped zero-valent iron, and the mass ratio of the two is 0.05-10:1, which can simultaneously remove heavy metal pollutants arsenic, cadmium and lead, and the adsorption capacity for cadmium and lead is increased. The present application also provides a preparation method of the composite material, which comprises ball milling elemental sulfur and zero-valent iron to obtain sulfur-doped zero-valent iron, and then ball milling the sulfur-doped zero-valent iron with Shish Mine to obtain the composite material for heavy metal pollutant remediation. The ball milling modification method is simple, efficient and pollution-free. In addition, the present application also provides an application of the composite material for heavy metal pollutant remediation in remediation of arsenic, cadmium and lead heavy metal pollution environment.

This invention discloses an iron-based composite solid-phase carbon source for denitrification of wastewater with a low carbon-to-nitrogen ratio and its preparation method. This invention relates to the field of wastewater treatment technology and aims to solve the problem that traditional mixed solid-phase carbon sources suffer from unstable carbon release rates under fluctuations in hydraulic retention time / hydraulic load, easily leading to a sharp drop in denitrification efficiency. The method involves co-dissolving polyvinyl alcohol and sodium alginate to form a cross-linking carrier solution; mixing zero-valent iron powder, PHBV powder, and natural cellulose powder and adding them to the carrier solution to form a homogeneous slurry; freezing the slurry and then solidifying it in an acidic cross-linking solution containing calcium ions; followed by washing and vacuum drying to obtain the iron-based composite solid-phase carbon source. The carbon source obtained by this invention has the characteristics of stable carbon release, high denitrification efficiency, and strong resistance to fluctuations in hydraulic load, making it particularly suitable for deep denitrification treatment of wastewater with a low carbon-to-nitrogen ratio.

This invention proposes a passivation remediation agent for arsenic-contaminated soil and its application. The passivation remediation agent constructs a ternary synergistic remediation system of zero-valent iron, phosphate, and dithiocarbamate through multi-component synergistic action, mainly including four core mechanisms: redox-adsorption-precipitation-chelation. Simultaneously, biochar, as a carrier, can reduce the risk of zero-valent iron agglomeration and deactivation, maintaining its high reactivity and significantly improving arsenic fixation efficiency. The introduction of dithiocarbamate can fill the gap in the insufficient fixation capacity of traditional iron-based materials for As(III). The calcium phosphate and magnesium phosphate used in this invention hydrolyze in the soil, adjusting the soil pH to a neutral or slightly alkaline range, reducing the solubility of arsenic. The positively charged surface of the iron oxide further facilitates the fixation of negatively charged AsO4. 3‑ Adsorption occurs. Furthermore, the alkaline properties of biochar further enhance this effect.

The utility model discloses a zero valence iron fenton reaction device of impingement stream coupling stirrer reinforced mass transfer belongs to wastewater treatment equipment technical field, including device body, wastewater liquid inlet and reagent adding mouth, and the upper portion of device body inner chamber is equipped with impingement stream reactor, one side of impingement stream reactor is equipped with first tapering nozzle, and the other side is equipped with second tapering nozzle, and wastewater liquid inlet is connected first tapering nozzle liquid inlet end through pipeline, and reagent adding mouth is connected second tapering nozzle liquid inlet end through pipeline, and the first tapering nozzle is left with reinforced mixing area between second tapering nozzle, and the lower portion of device body inner chamber is equipped with axial flow stirrer, and the lower portion of device body is equipped with liquid outlet symmetrically, and is connected first tapering nozzle and second tapering nozzle respectively through circulating pipeline. The utility model discloses through the impingement stream reactor of upper portion realizes instantaneous strong mixing, realizes sustained steady mass transfer through the axial flow stirrer of lower portion and circulating pipeline to realize all cycle mass transfer reinforcement.

This invention discloses an iron-carbon micro-electrolysis filler for the degradation of nitroguanidine wastewater and its preparation method. It is prepared using red mud as the iron source, waste oil as the carbon source, and potassium hydroxide as the pore-forming agent. This invention utilizes strong acid to etch the red mud, extracting iron from it. Adjusting the pH of the leachate yields high-purity Fe(OH)3, which is then decomposed into Fe2O3 at high temperature and subsequently carbothermally reduced to zero-valent iron. This avoids the silicon and aluminum in the red mud coating the zero-valent iron, thus preventing it from affecting the micro-electrolysis effect. The zero-valent iron has good contact with the carbon material, effectively forming a galvanic cell. Using liquid waste oil and organic flocculants as the carbon material and reducing agent sources increases the contact between the carbon material and iron oxide, improving the reduction efficiency. KOH etching of the carbon material forms channels, preparing a porous composite material that enhances the adsorption and enrichment of pollutants. Compared with existing red mud-based iron-carbon micro-electrolysis materials, this method is simpler, lower in cost, and easier to scale up.

The application discloses phosphatized micron zero-valent iron which is strengthened by liquid nitrogen freezing treatment, and a preparation method and application thereof. The phosphatized micron zero-valent iron is obtained by mixing micron zero-valent iron powder and a phosphatized precursor and ball milling through a mechanochemical method, and the phosphatized micron zero-valent iron is subjected to low-temperature freezing by liquid nitrogen to obtain the phosphatized micron zero-valent iron which is strengthened by liquid nitrogen freezing treatment. The phosphatized micron zero-valent iron which is strengthened by liquid nitrogen freezing treatment has high removal efficiency for heavy metal-organic reagent complex in mine wastewater and strong cyclic reactivity, realizes one-stop removal of heavy metals and synchronous degradation of organic ligands, and does not need to add an oxidant and a precipitant; the preparation process is simple, environment-friendly and low in cost, and the phosphatized micron zero-valent iron which is strengthened by liquid nitrogen freezing treatment is expected to be practically applied to treatment of mine wastewater which is polluted by heavy metal-organic reagent complex.

The application belongs to the technical field of water treatment, and provides sulfur quantum dot modified zero-valent iron as well as a preparation method and application thereof.The sulfur quantum dot modified zero-valent iron is composed of zero-valent iron and sulfur quantum dots loaded on the surface of the zero-valent iron, and the sulfur quantum dots are uniformly and discretely distributed on the surface of the zero-valent iron.By adjusting the coordination environment and electronic structure of the metal center of the zero-valent iron, the reaction activity of the zero-valent iron is enhanced, the ability of the zero-valent iron to activate oxidants to degrade organic pollutants is improved, meanwhile, the pH applicable range of the zero-valent iron in treating wastewater is widened, and the degradation efficiency of the zero-valent iron on organic pollutants in wastewater is improved.

The application discloses a kind of electromagnetic induction zero-valent iron soil solid waste perfluoroalkyl compound removal method and device, it is related to environmental protection equipment technical field.The device includes spiral feeder, feed tank, energy recovery preheating section, electromagnetic heating section, medium-high frequency power supply, heating coil and the like.Perfluoroalkyl compound-containing material is mixed with zero-valent iron particles, after preheating, into electromagnetic heating section, zero-valent iron is inductive heating in alternating electromagnetic field, in situ heating and reducing degradation perfluoroalkyl compound, and zero-valent iron can be recycled and used.The application breaks through the limitation of traditional single physical thermal desorption or chemical adsorption, realizes "heating-degradation" simultaneously, and fundamentally improves the thoroughness of pollutant removal.The application can realize heating and degradation simultaneously, with high energy efficiency and complete removal.The whole device has simple structure, can be operated continuously, has strong adaptability, and has good engineering application prospect.

This invention discloses a biochar-supported self-doped pyridine nitrogen-confined nZVI material and its preparation method, relating to the field of wastewater treatment materials technology. Utilizing the self-doped nitrogen properties of chitosan, pore-forming and mechanical strength-enhancing processes are achieved using polyethylene glycol and sodium alginate, respectively. A two-step pyrolysis process forms a nitrogen-doped iron-carbon micro-electrolysis filler. The synergistic effect of multiple nitrogen species, pyridine nitrogen and graphitic nitrogen, optimizes the reaction pathway, thereby increasing NO3- content in nitrate wastewater. ‑ The invention improves the removal rate of -N and the N2 selectivity of the product, and, based on the formation of a microscopic galvanic cell between zero-valent iron and biochar, alleviates the pH limitation of nZVI when used alone, and enhances the nitrate removal rate. The biochar-supported self-doped pyridine nitrogen-confined nZVI material prepared in this invention possesses comprehensive advantages, including good dispersibility, abundant active sites, optimized reaction pathways, synergistic dual-function properties, strong anti-interference ability, and recyclability, making it suitable for the efficient remediation of nitrate wastewater and complex polluted water bodies.

This invention discloses a nano-zero-valent iron-supported nickel-cobalt layered double hydroxide composite material, its preparation method, and its application, belonging to the field of environmental functional materials. The composite material uses NiCo-LDH as a carrier, and nano-nZVI is in-situ loaded onto the surface of NiCo-LDH nanosheets via a liquid-phase reduction method to obtain an NC-nZVI composite material. The preparation method includes: dispersing a water-soluble polymeric dispersant, nickel salt, and cobalt salt in water, adding dilute ammonia, and then performing a hydrothermal reaction to obtain NiCo-LDH nanosheets; subsequently, dispersing the NiCo-LDH nanosheets and ferrous salt in water, and adding sodium borohydride solution under an inert atmosphere to reduce ferrous ions in-situ to generate nano-zero-valent iron, which is then anchored on the surface of the NiCo-LDH nanosheets. This composite material can alleviate the problems of nZVI aggregation and surface passivation, increase the exposure of reactive sites, and can be used for the simultaneous removal of pollutants in water bodies containing hexavalent uranium (U(VI)) and tetracycline (TC).

This invention provides a lattice sulfur-controlled doping of zero-valent iron, its preparation method, and its application in the removal of perfluorinated compounds from groundwater. The preparation method involves adding a sulfur source and a reducing agent to a solution containing Fe. 3+ In a salt solution under a protective atmosphere, lattice sulfur-controlled doped zero-valent iron is obtained through a reaction. This invention prepares sulfur-doped modified sulfide nano-zero-valent iron via a simple liquid-phase reduction method, which can further suppress the hydrogen evolution side reaction of zero-valent iron, regulate interfacial electron transfer and solution redox potential, and improve the yield and lifetime of hydrated electrons of key reducing species, thereby further enhancing the defluorination effect on perfluorinated compounds.

The application discloses low-cost sulfidized nano zero-valent iron based on a pyrite oxidation-reduction path and application thereof. Low-cost sulfidized nano zero-valent iron is obtained by the mode of air oxidation and then hydrogen reduction of cheap pyrite powder in a tube furnace. By adjusting and controlling parameters such as oxidation temperature, oxidation time and reduction time, the low-cost lattice-doped sulfidized nano zero-valent iron with a median particle size of less than 300 nm and a zero-valent iron content of 70% is prepared, and the preparation cost is far lower than that of a laboratory liquid-phase synthesis method. The material can effectively degrade trichloroethylene and florfenicol, and has a small hydrogen production amount and a high electron efficiency. The preparation method is simple and easy to operate, and has a large-scale production prospect, and the degradation performance of pollutants is close to that of laboratory-prepared sulfidized nano zero-valent iron, so the material has a prospect of being applied to actual groundwater pollution remediation.

The application discloses a kind of red mud-coal gangue-based magnetic composite material and its preparation method and application, belong to water / soil treatment technical field.The composite material is core-shell structure, shell is carbon shell, inner core is the magnetic zeolite of load nano zero-valent iron, and the magnetic zeolite is prepared by red mud and coal gangue cooperation;Preparation method includes red mud-coal gangue pretreatment, alkali fusion activation and hydrothermal crystallization preparation magnetic zeolite, ethanol-water solvent load nZVI, PDA carbonization coating and the like steps.The application realizes double solid waste resource, and material has water body quick adsorption and soil long-acting stability performance, nZVI stability is strong, recycling rate is high, and magnetic separation is convenient, low in cost and environmental protection, suitable for lead, cadmium, copper and other heavy metal pollution treatment.