418 results about "Zerovalent iron" patented technology

The invention relates to a technology for removing and controlling arsenic which has very high toxicity in water, and discloses a water treatment method for removing arsenic by strengthening zero-valent iron, which can be used for groundwater repair, drinking water treatment, industrial arsenic-containing wastewater treatment, sewage deep treatment and integrated small-scale water treatment systems. The water treatment method specifically comprises the following steps of: adding persulfate and zero-valent iron into water containing arsenic, wherein the persulfate is added in a molar ratio of the persulfate to arsenic of (5:1)-(100:1), and the molar ratio of the zero-valent iron to the persulfate in the water is (1:1)-(10:1); and when the mixed solution is fully mixed, filtering or depositing to finish the removal of arsenic. The water treatment method is very simple to operate, easy to popularize and apply and safe to use, and can be used for ensuring the water quality safety.

The invention provides a nanometer zero-valent iron-biochar composite material, and a preparation method and application thereof. According to the invention, a carrier is a series of biochar with different cracking temperatures; the biochar is cheap and easily-available, has large specific surface area and contains a plurality of mineral components; nanometer zero-valent iron particles carried bythe carrier have strong activity; thus, the nanometer zero-valent iron particles have high activity; and the nanometer zero-valent iron-biochar composite material prepared from the carrier has high activity, and has the advantages of stable properties and low price at the same time. Screening of the series of different cracking temperatures shows that the composite material formed by the biochar generated by cracking of straw at medium and high temperatures and the nanometer zero-valent iron has strong removal effect on heavy metals. Meanwhile, the nanometer zero-valent iron-biochar compositematerial provided by the invention has excellent adsorption performance of the biochar and strong reduction capacity of the nanometer iron, and can provide theoretical basis and technical support forprevention, control and remediation of heavy metal pollution to groundwater.

The invention discloses a preparation method of modified micron zero-valent iron and an application method of the modified micron zero-valent iron in remediation of heavy metal contaminated soil. The preparation method of the modified micron zero-valent iron comprises the steps of cleaning of iron raw materials, preparation of micro iron, ultrafine grinding and modifying treatment. A modifying agent composed of water, xanthan gum, sulfide, a stabilizing agent, zeolite and blast furnace slag is adopted in the step of modifying treatment. The preparation method of the modified micron zero-valent iron has the beneficial effects that the production process of the modified micron zero-valent iron is simple, and the effect similar or superior to micron zero-valent iron is achieved while the cost is reduced; and in addition, the reaction activity is controlled, the oxidation rate is decreased, excellent stability is obtained, and the acting time of the micron zero-valent iron is longer. By the adoption of the application method of the modified micron zero-valent iron, the remediation cost of heavy metal contaminated underground water is further reduced. According to the preparation method of the modified micron zero-valent iron and the application method of the modified micron zero-valent iron in remediation of heavy metal contaminated soil, organic fertilizer is added in the soil treatment process so that the fertility of soil can be improved, the structure of soil can be improved through humic acid produced by the organic fertilizer, heavy metal elements, such as lead, chromium and arsenic, in underground water can be removed, and the concentration of pollutants such as nitrate and perchlorate can be reduced.

The invention discloses a mesoporous silicon dioxide microsphere-loaded zero-valent iron nanoparticle and a preparation method thereof. The mesoporous silicon dioxide microsphere-loaded zero-valent iron nanoparticle has a structure as follows: the center is mesoporous SiO2, the middle layer is FeOOH, the surface of the outermost layer is coated with FeO, and ultimately a SiO2@ FeOOH@Fe structure, namely a spherical particle, is formed. The preparation method is easy to operate and mild in reaction conditions, can be carried out at room temperature and normal pressure, and is short in time consumption and low in energy consumption; the prepared mesoporous silicon dioxide microsphere-loaded zero-valent iron nanoparticles have the particle size of 400-500nm and are spherical particles; the specific surface areas of the prepared mesoporous silicon dioxide microsphere-loaded zero-valent iron nanoparticles are detected to be 383.477m2/g by a BET-N2 specific surface area analysis method; and the prepared mesoporous silicon dioxide microsphere-loaded zero-valent iron nanoparticles are good in lattice morphology, good in fluidity and good in dispersion and can be used for decomposing organic pollutants in the environment.

The invention discloses a water treatment method of zero-valent iron-copper bi-metal activated persulfate. The water treatment method specifically comprises the steps that bi-metals including zero-valent iron and copper are added into water containing micro-pollutants, then persulfate is added, full mixing is performed, the bi-metals including the zero-valent iron and the copper are utilized to activate the persulfate so as to remove the micro-pollutants in the water. The water treatment method utilizes the bi-metals including the zero-valent iron and the copper to efficiently activate the persulfate so as to produce free sulfate radicals having strong oxidizing property, can achieve the purpose of quickly and thoroughly removing micro-pollutants, including multiple types of poisonous and harmful micro-pollutants in water, such as polychlorinated biphenyl, brominated flame retardants, drugs and personal care products (PPCPs) and algal toxin, and has the advantages of high activation efficiency, high oxidation and degradation efficiency of pollutants, wide pH using range, convenient operation and the like. The water treatment method can be applied to underground water remediation, treatment of industrial water (including electroplating wastewater, hospital wastewater, printing and dyeing wastewater and the like), drinking water treatment, wastewater treatment and the like.

The invention belongs to the technical field of nano material preparation and relates to a silica micropowder loaded type nano zerovalent iron particle and a preparation method thereof. The method comprises the following steps of: (1) preparing modified silica micropowder; (2) removing oxygen; (3) preparing a nano iron solution; and (4) preparing nano zerovalent iron particles. In the invention, a liquid-phase reduction method is adopted to prepare the silica micropowder loaded type nano zerovalent iron particles, and a strong reducing agent KBH4 or NaBH4 is used for reducing Fe<3+> to obtain Fe<0>; loading is carried out through the silica micropowder to ensure that the agglomeration resistance of the nano zerovalent iron particle is greatly improved; the prepared nano zerovalent iron particles are uniformly distributed and have small mean grain size and large specific surface area; and the pollutant removal capacity of the nano zerovalent iron particles is far higher than that unloaded nano iron, and the nano zerovalent iron particles have stronger mobility in simulated soil, and can be widely applied to the field of environmental modification.

The invention discloses a Fe/C composite porous structure material as well as a preparation method and application thereof. The Fe/C composite porous structure material is characterized by being prepared from low-grade sedimentary iron ore and biomass as raw materials in manners of crushing, mixing, extrusion molding and pyrolysis and reduction reaction in the presence of hydrogen atmosphere at 650-900 DEG C, wherein the main phase composition comprises biomass carbon and zero-valent iron. The Fe/C composite porous structure material disclosed by the invention is high in opening porosity, magnetic susceptibility, adsorbability and biological chemical activity, can be used for treating eutrophicated river water, living sewage and landscape water bodies, or can be used for mediation of underground water pollution and polluted soil.

The invention relates to a method and a device for purifying cadmium in waste water through nano zero-valent iron, and the cadmium-contained waste water refers to the waste water with severe pollution and needing to be purified in the production and application field of smelting and different cadmium compounds. By adopting the nano technology, a great amount of cadmium elements in the waste water is purified and removed by utilizing nano zero-valent iron through a continuous flow secondary reaction device. Water is discharged in a weir flow way after the waste waster flows by a secondary treatment device consisting of a reaction chamber and a separation chamber, the waste water is adequately contacted and reacted with the nano zero-valent iron particles through the electric blending inside the reaction chamber, the nano zero-valent iron particles are promoted to precipitate by utilizing an oblique plate inside the separation chamber so as to be separated from the waste water, and the precipitated nano zero-valent iron backflows to the reaction chamber to be circulated. A layer of filter membrane is paved on a water outlet of a weir flow water outlet groove so as to filter the nano zero-valent iron particles which are not completely precipitated in the water. The process flow for removing cadmium pollutant in the waste water is simple, the cost is low, convenience in operation is achieved, the treatment effect is good, and no secondary pollution is caused.

The invention discloses a preparation method of a carbon-sulfur doped zero-valent iron composite material, which comprises the following the step: proportionally mixing and ball-milling a sulfur reagent, iron powder and carbon powder to obtain the carbon-sulfur doped zero-valent iron composite material; the sulfur reagent is elemental sulfur powder, iron sulfide powder or pyrite powder; the mass percentage ratio of the sulfur reagent to the iron powder to the carbon powder is (0.5-20): (70-99): (0.5-10). The sulfur reagent, the iron powder and the carbon powder are mixed and then subjected toball milling to obtain the carbon-sulfur doped zero-valent iron composite material, and the carbon-sulfur doped zero-valent iron composite material can be used for in-situ removal and degradation of heavy metal pollutants, pesticide pollutants, azo dye pollutants, halogenated organic matter pollutants and/or nitro organic matter pollutants in underground water and soil and has high removal and degradation efficiency.

The invention relates to a wastewater treatment filtering material, and a preparation method and a use thereof. The filtering material is formed by a porous ceramic matrix having an amount of porosity of 35-85% and nanometer zerovalent iron particles in-situ generated in the porous ceramic matrix, the micropore size of the porous ceramic matrix is 2-10mum, a fuzzy amorphous silicon-iron-carbon structure is formed in the micropore and can form an adsorbing film after absorbing water, and the material of the porous ceramic matrix is composed of 55-65 parts by weight of diatomite, 12-15 parts by weight of calcium-based bentonite, 7-12 parts by weight of carbon powder, 2-3 parts by weight of starch, and 4-6 parts by weight of kaolin. The filtering material obtained in the invention forms a nose-like porous fluffy filtering structure in the microstructure and generates the adsorbing film, so the absorbing efficiency is greatly improved, and the filtering material can be adapted to the chemical environment change of water. The shedding or heavy metal precipitation of the used filtering material does not appear, and the use safety of the filtering material is good.

The invention belongs to the technical field of high-toxicity pollutant treatment, and relates to a simple and convenient method for loading superfine nano zero-valent iron on a porous material and application of the porous material as an adsorbent and a heterogeneous Fenton catalyst for degrading and removing pollutants. The organic iron salt, the organic ligand and the porous material only needto be simply mixed and then are subjected to high-temperature carbonization under the protection of inert gas, so that the superfine zero-valent iron can be uniformly loaded on the inner and outer surfaces and pore passages of the porous material. According to the method, a complex, time-consuming and harsh liquid-phase impregnation process in a conventional liquid-phase reduction method is omitted, no solvent or dispersing agent is needed, and the utilization rate of raw materials is high. The obtained zero-valent iron is large in loading capacity, good in crystallinity and small in particlesize. The porous material loaded with the superfine nanoscale zero-valent iron can be used as an adsorbent and a catalyst, and high-toxicity inorganic and organic pollutants in a water body are removed by utilizing adsorption, an Fe-C micro-electrolysis technology and a Fenton oxidation technology.

The invention discloses a preparation method of zero-valent iron sulfide and application thereof. The preparation method comprises the steps that under the ambient temperature condition, zero-valent iron and simple-substance powdered sulfur are mixed to be subjected to a reaction in a water solution to obtain zero-valent iron sulfide. According to the method, zero-valent iron and simple-substancepowdered sulfur are mixed to be subjected to the reaction in the water solution, little energy is consumed, operation is easy and convenient, the preparation time is relatively short, the preparationcost is low, and the obtained zero-valent iron sulfide has the high removal efficiency for heavy metal and organic contaminants.

The invention relates to the field of preparation and application of novel iron-based biochar, in particular to a preparation method for a novel iron-based biochar repair material which is used for treating polluted soil. The preparation method is characterized by comprising the following steps: performing anaerobic dry distillation on a biomass raw material which is carried with an iron oxide in a dry distillation furnace; performing reducing, cracking and polymerizing reactions on the biomass to generate energy conversion; separating reductive gases, namely CO and H2; under a proper temperature, gradually reducing part iron oxide which is loaded on the surface of the biomass into zero-valent iron. Electrode potential difference exists between iron and carbon, so that a micro primary cell can be formed in soil solution; moreover, the iron oxide which remains on the surface of the biochar has a very good removal capacity to arsenic, so that the treatment effect on the pollutants in soil is enhanced very well; according to the preparation method and the application of the novel iron-based biochar, environmental effects of the biochar, the zero-valent iron and the iron oxide are combined, so that the problem of repair function loss of the biochar is solved; the repair efficiency is improved; the application potential of the novel iron-based biochar in the aspect of soil body pollution control is expanded.

A method of removing nitrates from water by utilization of a zero-valent iron/oxidizing agent/zeolite synergetic system is provided. The zero-valent iron is common iron powder. The oxidizing agent is a common oxidizing agent used in water treatment. The zeolite is natural zeolite or artificial zeolite. The method is characterized in that: the oxidizing agent in the system oxidizes and strips a passivation layer formed on the surface of the zero-valent iron to allow electrons in the zero-valent iron to be transferred continuously to the outside, so that the zero-valent iron maintains high reduction activity to reduce the nitrates into ammonia nitrogen. Then efficient selective absorption of the zeolite to the ammonia nitrogen is utilized to remove the ammonia nitrogen in the water body. The method is environmental friendly, simple, feasible, low in cost, and capable of being efficiently used for treatment of waste water containing nitrates of industrial enterprises and nitrate restoration and removal for underground water.

The invention relates to the fields of new material science and technology and environmental protection technology and particularly discloses a preparation method of a nitrogen-doped iron-carbon material with a core-shell structure and suitable for magnetic field recovery and an application method thereof in an advanced redox water treatment technology. The nitrogen-doped iron-containing metal organic framework is a high-performance iron-carbon composite material obtained through precursor one-step carbonization. The iron element in the material is mainly fixed in the form of zero-valent ironin the porous carbon material so that a core-shell structure is formed. The nitrogen-doped carbon material shell can protect the zero-valent iron and prolong the service life of the iron-carbon composite material. The iron-carbon composite material has the catalytic oxidation ability of an activated peroxide oxidant, can be applied to the advanced oxidation system, has good interface reducing ability of zero-valent iron and realizes efficient removal of multiple pollutants in the water.

The invention discloses a preparation method and the application of modified zeolite permeable reactive wall filling carrying zero-valent iron powder, and belongs to the field of underground water environment modification. The method comprises the following steps: soaking clinoptilolite in 16-20g/L of cetyl trimethyl ammonium bromide (CTAB) Br solution, and modifying the clinoptilolite for over 12h in a constant-temperature shaking table at normal temperature; washing the modified clinoptilolite for 5-6 times with distilled water, and drying the clinoptilolite for later use; adding iron powder into 10-30g/L of sodium alginate solution; performing full and uniform stirring to form a mixture of the iron powder and the sodium alginate solution; performing full stirring to uniformly disperse the mixture of the iron powder and the sodium alginate solution on the surface of the modified zeolite; pouring the mixture into 20-40g/L of CaCl2 solution, and soaking and maintaining the mixture for 24h with the CaCl2 solution; stirring and washing the mixture with hydrochloric acid, and then washing the mixture to be neutral with the distilled water. According to the preparation method, the problem of loss of the iron powder is effectively solved, and the removal rate of hexavalent chromium with modified zeolite filling carrying the iron powder is two times of the removal rate of the hexavalent chromium with the modified zeolite.

The invention discloses a method for removing hexavalent chromium in water by using a biochar-loaded nanometer iron-nickel composite material, and relates to a remediation method for heavy metal pollution in a water body. According to the invention, the biochar-loaded nanometer zero-valent iron-nickel bimetallic composite material is prepared in one step by using a simplified biochar-supported bimetallic material preparation process without the use of a high-cost strong reducing agent, and is applied to removal of Cr (VI) in water, so that the problems of easy surface passivation, low reactionactivity and low utilization rate in the treatment of heavy metals in a water body with nanometer zero-valent iron; and the method has advantages of low cost, simple operation and no secondary pollution, and the Cr (VI) removal activity and the stability of the biochar-loaded iron-nickel bimetallic material are higher than the Cr (VI) removal activity and the stability of the biochar-loaded nanometer zero-valent iron material.

The invention provides a biochar-loaded nanometer sulfurized zero-valent iron material and a preparation method and application thereof. The method comprises the following steps: mixing biomass and aFeSO4 solution in a vacuum or inert atmosphere, evaporating to dryness, grinding and drying to obtain FeSO4-loaded biomass; and pyrolyzing the FeSO4-loaded biomass at 800-1000 DEG C in an inert atmosphere to obtain the biochar-loaded nano zero-valent iron sulfide material. The material is prepared by adopting a one-pot pyrolysis method, the method is simple, and the biochar-loaded nano zero-valentiron sulfide material can improve the dispersity and stability of nano zero-valent iron sulfide, so that the reaction activity of the nano zero-valent iron sulfide on halogenated organic matters is improved, and sewage containing the halogenated organic matters is rapidly and effectively treated. Vulcanization modification not only enhances the reaction activity of the material, but also improvesthe aging resistance of the material in water, and inhibits the passivation of the material, thereby prolonging the service life of the zero-valent iron and improving the degradability of zero-valentiron.

The invention discloses a method for preparing zerovalent iron nanoparticles by an improved liquid phase reduction method. The method comprises the following steps of: (1) preparing 0.03 to 0.07mol/L Fe3<+> solution in distilled water; (2) adding NaF in an amount which is 7 to 9 times that of the Fe3<+> into the solution in step (1) to form FeF63<-> solution; (3) adding tetrahydrofuran into the system in step (2), wherein the volume ratio of the tetrahydrofuran to the solution in step (1) is 1:2-2:1; (4) dissolving KBH4 into the mixed solution of tetrahydrofuran and water, and reacting under the stirring; and (5) washing iron nanoparticles with distilled water and ethanol respectively, and keeping the iron nanoparticles in absolute ethanol. In the process of synthesizing the iron nanoparticles, an organic macromolecule surfactant does not need to be added; nitrogen protection is not needed; the equipment is simple; and the operation is convenient. The prepared iron nanoparticles are uniformly distributed; the average grain diameter is 50nm; the dispersibility is relatively good; the specific surface area is 42 to 60m<2>/g; and an impurity, namely iron oxide, does not appear.

The invention relates to an integrated process for treating heavy metal wastewater. A reactor adopted in the integrated process is simple to construct, compact in structure, high in heavy metal wastewater treatment efficiency, and easy to operate, manage and maintain. The integrated process is free of a nanometer zero-valent iron mixed solution refluxing device, capable of increasing the nanometer zero-valent iron by sufficiently utilizing flow fields, which are formed by a stirring device on the inner part of the reactor, and capable of realizing solid-liquid separation and zero-valent iron refluxing by utilizing the gravity of the nanometer zero-valent iron, so that the nanometer zero-valent iron is sufficiently mixed and circulated in the reactor, and the high-adsorption performance and strong reduction characteristic to the heavy metals are greatly utilized. An integrated device is used to treat simulated wastewater and the pre-treated electroplating wastewater containing heavy metals, so that the concentration of various heavy metals in the treated outlet water are better than the emission standards of the national pollutant I. Moreover, the reactor has short hydraulic retention time and high treatment efficiency, and is free of additionally added chemical coagulant, capable of separating and recycling the nanometer zero-valent iron containing heavy metals and capable of avoiding the secondary pollution of the heavy metals.

The invention discloses an excess sludge treatment method which comprises the following steps: adding excess sludge to a reaction tank, with high speed stirring at 15-50 DEG C, adding a surfactant and sodium percarbonate to the reaction tank, after 0.5-5h of reaction, adding nano zero-valent iron, at 15-50 DEG C reacting for 1-8h, sending the sludge into a magnetic separator to remove the nano zero-valent iron containing heavy metals in the sludge; performing mechanical dewatering of the treated sludge to respectively obtain purified sludge and water. The excess sludge treated by the method is low in water content and high in heavy metal removal rate, the treated water is low in (chemical oxygen demand) COD value, and the excess sludge treatment method is low in cost, green, and free of secondary pollution, and can lay a foundation for agricultural or forestry sludge or other resource method.

The invention relates to a method for removing harmful substances in sludge by using nano zero-valent iron. The sludge is solid precipitate generated by a sewage treatment process, and is composed of microbes, organic and inorganic solids, trace heavy metals and the like. By adopting nano technology, sludge and nano iron are thoroughly mixed, so that organic compounds and heavy metals in the sludge are reduced by the nano iron, inorganic substances and reduced heavy metal ions in the sludge are adsorbed to the surface of the nano iron, and the reacted sludge and nano iron are effectively separated by an electromagnetic rake device. Compared with the conventional sludge treatment method, the invention using nano iron technology to degrade pollutants in the sludge has the characteristics of low cost, time saving and the like, and is simple to operate; the active iron, especially nano iron, can quickly degrade and stabilize the pollutants in the sludge; and the traveler-type electromagnetic rake device is utilized to recover the nano iron, thereby avoiding secondary pollution.

The invention discloses a pyrolytic carbon loaded zero-valent iron (ZVI) composite material, and a preparation method and an application thereof. The method comprises the following steps: mixing natural hematite powder with crushed pine biomass according to a mass ratio, adding water, performing ultrasonic dispersion, drying the obtained raw material mixture, putting the obtained dried raw material mixture into a tubular furnace, carrying out oxygen-limiting pyrolysis in a hydrogen-argon mixed gas atmosphere, raising the temperature to a target temperature of 800-1500 DEG C at a preset heatingrate, and carrying out joint pyrolysis on pine biomass and natural hematite (the main component is Fe2O3) to reduce Fe2O3 into ZVI and generate the composite material PC/ZVI. Doping with graphene and/or p-benzoquinone can supplement functional group loss of a carbon material after high-temperature pyrolysis, further promotes zero-valent iron electron transfer and remarkably improves the heavy metal removal capacity.