747 results about "Cadmium" patented technology

The invention relates to the technical field of in-situ / ex-situ remediation of sites polluted by heavy metals such as cadmium, lead, copper and zinc, and discloses a heavy metal polluted soil remediation system and method based on intelligent management and control. The system comprises an electrode system module, an activator module, a targeted adsorption device module, an automatic monitoring system module, an intelligent decision-making system module and a photovoltaic power supply module. The method comprises the steps of driving heavy metal ions in soil to directionally migrate through an electric field; the activating agent module works, green micromolecule organic acid and other activating agents are injected in a gradient mode, and the migration efficiency of heavy metal is improved; activated heavy metal ions can be captured by an adsorption material in the targeted adsorption device module in cooperation with a selective enrichment device; meanwhile, the automatic monitoring system module collects environmental parameters in real time; the intelligent decision-making system module optimizes the remediation efficiency and energy consumption according to the real-time data, and low-cost and high-efficiency remediation of soil heavy metal pollution is achieved. The remediation efficiency is remarkably improved, and the risk of secondary pollution is reduced.

The invention discloses a high-weather-resistance bismuth vanadate coating and a preparation method thereof, and belongs to the technical field of inorganic pigment modification. The high-weather-resistance bismuth vanadate coating comprises bismuth vanadate matrix particles, and the surfaces of the bismuth vanadate matrix particles are sequentially coated with an amorphous aluminum oxide layer, a cerium oxide layer and a fluorinated silicon oxide layer. The amorphous aluminum oxide layer is formed in an atomic layer deposition mode; the cerium oxide layer is formed by hydrothermal treatment of a cerium source. The preparation technology has accurate and controllable technological parameters, is suitable for industrial production, can replace the traditional toxic pigment containing lead and cadmium, and meets the requirements of environmental regulations. The bismuth vanadate coating has excellent weather resistance and chemical stability, the service life of a product can be prolonged, the maintenance cost is reduced, and a reliable solution is provided for development of high-performance environment-friendly pigments.

The invention belongs to the technical field of phosphoric acid purification, and particularly relates to a removing agent and a removing method for heavy metal cadmium in phosphoric acid. The removing agent comprises a solvent, a thiophosphoric acid trapping agent A and a thiophosphoric acid trapping agent B, wherein the thiophosphoric acid trapping agent A and the thiophosphoric acid trapping agent B are dispersed in the solvent; the thiophosphoric acid trapping agent A and the thiophosphoric acid trapping agent B are different types of thiophosphoric acid trapping agents and are respectively and independently selected from one of alkyl dithiophosphoric acid or salts thereof, phenolic dithiophosphoric acid or salts thereof and amino dithiophosphoric acid or salts thereof; and at least one hydrocarbyl dithiophosphoric acid or salt thereof is selected; the salt is sodium salt or ammonium salt; the solvent is water or an alkaline aqueous solution. According to the method, a composition of a dithiophosphoric acid trapping agent is used as a removing agent for cadmium in wet-process phosphoric acid, a precipitate which is insoluble in a strongly acidic water phase is generated after reaction, and phosphoric acid cadmium removal is realized after filtration. Compared with a conventional sulfide precipitation method, the method provided by the invention has the advantages of less cadmium residue in phosphoric acid and less pollution.

The invention discloses a cyanide-free cadmium-iron alloy plating process for high-strength structural steel. The cyanide-free cadmium-iron alloy plating process comprises the step that a nickel-titanium alloy plating layer, a cyanide-free cadmium-iron alloy plating layer and a hexavalent chromium passivation film are sequentially prepared on a high-strength structural steel substrate from inside to outside. The prepared sample piece is subjected to a hydrogen brittleness test according to HB 5067.1-2005 Part 1 of hydrogen brittleness test of plating process: Mechanical Method, and the test result meets the standard requirement; the surface of a plated part is free of white rust after being subjected to an acetate mist test for 400h according to GB / T 10125-2021 Artificial Atmosphere Corrosion Test Salt Spray Test, and a plating layer of the plated part has excellent corrosion resistance; according to GB / T 5270-2005 < GB / T 5270-2005 < GB / T > 5270-2005 < GB / T > 5270-2005 > < GB / T > 5270-2005 > < GB / T > 5270-2005 > < GB / T > 5270-2005 > < GB /

The invention relates to the technical field of cadmium element analysis, in particular to a biological available cadmium content determination method for soil detection. According to absorbance distribution of different samples under stable correlation wavelengths and cadmium element concentration difference, the cadmium element influence degree of each stable correlation wavelength is obtained, and high-influence wavelengths are screened out; constructing a univariate regression model by using the absorbance of the cadmium standard solution under each high-influence wavelength and the cadmium element concentration, sequentially screening corresponding optimal variables in the high-influence wavelengths based on an AIC forward selection method, and iteratively adding the optimal variables into an empty model to obtain a final cadmium detection model; and obtaining a variable coefficient of a final cadmium detection model according to the absorbance of different samples and cadmium standard solutions under different high influence wavelengths and the corresponding cadmium element influence degrees. By analyzing the influence degree of cadmium elements of different wavelengths, a proper cadmium detection model is constructed, and the accuracy of effective-state cadmium content determination is improved.

The invention relates to a manganese cadmium sulfur and manganese sulfide heterojunction composite photocatalytic material, which is composed of Mn < 0.7 > Cd < 0.3 > S and MnS. The invention also discloses a preparation method of the manganese-cadmium-sulfur-coated manganese sulfide heterojunction composite photocatalytic material. The preparation method specifically comprises the following steps: preparing the manganese-cadmium-sulfur-coated manganese sulfide heterojunction photocatalytic material through a one-step hydrothermal method; (CH3COO) 2Mn. 4H2O and (CH3COO) 2Cd. 2H2O are added, and the mixture is stirred and dissolved in water; adding the mixture into TAA and stirring for 30 minutes to obtain a fully mixed solution; and carrying out a hydrothermal reaction to obtain the final manganese-cadmium-sulfur-coated manganese sulfide heterojunction photocatalytic material. According to the invention, the photoresponse range is widened through the construction of the heterojunction, the transfer and separation efficiency of photo-induced electron holes is obviously improved, the compounding of photo-induced electron hole pairs is inhibited, and the efficiency of photocatalytic uranium reduction is improved.

The invention relates to the technical field of agriculture, in particular to a preparation method and an application method of a zinc-rich cadmium-reducing yield-increasing foliar fertilizer. The specific technical scheme is as follows: the zinc-rich cadmium-reducing yield-increasing foliar fertilizer is prepared from the following components in percentage by mass: 20 to 30 percent of porous chitosan, 30 to 40 percent of L-malic acid and 40 to 50 percent of nano zinc oxide. The technical problem that in the prior art, the zinc content of rice cannot be increased, meanwhile, the rice yield cannot be increased, and the cadmium content of rice cannot be reduced is solved.

The invention discloses a zinc sulfate solution impurity removal method based on a three-section countercurrent purification process, and belongs to the technical field of hydrometallurgy. Heating the zinc sulfate solution containing impurities to 60-70 DEG C in a first-section reaction tank, reacting for 30-60 minutes, adding the second-section pressure filter residue, and performing pressure filtration to obtain a first-section purified solution and a first-section pressure filter residue; the first-section purified liquid is transferred into a second-section reaction tank, zinc powder and third-section filter residues are added, the adding amount of the zinc powder is 0.8-2 times of the theoretical amount of the zinc powder needed for metal cadmium replacement, the temperature is increased to 70-80 DEG C, a reaction is conducted for 60-90 min, and second-section purified liquid and second-section filter residues are obtained after filter pressing; the second-section purified liquid is transferred into a third-section reaction tank, zinc powder is supplemented, the adding amount is 180-300 times of the theoretical amount of the zinc powder needed for metal cobalt replacement, the temperature is increased to 80-90 DEG C, a reaction is conducted for 90-120 min, and third-section purified liquid and third-section filter pressing residues are obtained after filter pressing; and returning the third-section press-filter residue to the second-section reaction tank, returning the second-section press-filter residue to the first-section reaction tank, and reversely recycling. The method has the advantages of sufficient reaction kinetics, high utilization rate of zinc powder, low zinc content in purified slag, simple process, deep impurity removal, low consumption and high efficiency.

The invention discloses a sodium alginate embedded iron-carbon microcapsule material for repairing cadmium and arsenic polluted soil and a preparation method of the sodium alginate embedded iron-carbon microcapsule material, and belongs to the technical field of soil heavy metal pollution repairing materials. The material comprises straw biochar, high-iron steel slag powder, a sulfydryl acetylated chitosan-iron monatomic cluster compound, a boron-doped graphitized carbon coated cobalt ferrite nanosheet, sodium alginate, calcium chloride and sodium carbonate. Wherein the sulfydryl acetylated chitosan is prepared by reacting chitosan with sulfydryl acetic anhydride, dialyzing and drying, and performing solvothermal reaction with ferric nitrate under high pressure. The preparation method comprises the following steps: pyrolyzing and drying the straw biochar, reacting the high-iron steel slag with sulfuric acid, adding the biochar, adjusting the pH value, adding sodium carbonate, mixing to obtain an iron-carbon-based passivation material, mixing with two modified compounds, mixing with a sodium alginate solution, dropwise adding a calcium chloride solution, and stirring and curing. The material can be applied to remediation of cadmium and arsenic polluted soil.

The invention belongs to the technical field of heavy metal treatment, and particularly relates to a synthesis method and application of a sludge biochar Schwertmannite composite material capable of synchronously mineralizing cadmium and arsenic. Municipal or industrial sludge is used as a raw material, sludge biochar rich in Ca, Fe and alkaline functional groups is prepared through pyrolysis, then the sludge biochar is deeply compounded with Schwertmannite through a high-energy ball milling technology, a core-shell-like nested structure is formed through induction, and a large number of reaction sites are exposed. Under the condition that As / Cd coexists, the surface of the composite material can be induced to generate stable minerals, a synchronous precipitation mechanism is formed, and As and Cd have an adsorption synergistic enhancement effect. The process is wide in raw material source, clean and efficient in preparation process and free of high-temperature hydrothermal or organic reagents, has cation exchangeability, alkali energy storage and carbon immobilization value, provides a new theory and material support for long-term environment immobilization of multi-metal pollutants, and has large-scale application potential.

The invention provides a photocatalyst based on sulfide homogeneous heterojunction and a preparation method and application thereof, and belongs to the technical field of photocatalysts. The photocatalyst based on the sulfide homogeneous heterojunction provided by the invention is a heterojunction formed by twin-crystal sulfur-cadmium-manganese and transition metal sulfide, has excellent structural stability, and can provide more photo-induced electrons. Therefore, when the photocatalyst provided by the invention is used for degrading H2S to produce hydrogen, the Schottky junction of the photocatalyst can reduce the hydrogen production overpotential, H2S is effectively decomposed to produce hydrogen, and meanwhile, a product Na2S2O3 with a high additional value is produced. The result of the embodiment shows that the photocatalyst based on the sulfide homogeneous heterojunction has excellent catalytic activity when being used for degrading H2S to produce hydrogen.

The invention discloses a process for comprehensively utilizing sintering machine head ash, which comprises the following steps of: preparing the sintering machine head ash, oxidizing and leaching, carrying out filter pressing, and washing chlorine and dehydrating a filter cake to obtain fine iron powder; the method comprises the following steps: preparing metal cesium by replacing and recovering valuable metal from filtrate, performing primary heavy metal removal, performing secondary impurity removal, performing evaporative crystallization, crystallizing potassium chloride and sodium chloride, extracting cesium, concentrating and crystallizing a cesium chloride solution, preparing metal cesium, extracting rubidium from cesium extraction raffinate, and concentrating and crystallizing a rubidium chloride solution, thereby preparing metal rubidium; after the metal replacement powder is dissolved by a certain concentration of acid, copper, zinc, gold, silver and bismuth in the metal replacement powder are recovered step by step, and toxic and harmful elements such as thallium, chromium and cadmium are concentrated from a system. The method can comprehensively and efficiently recover sylvite, sodium salt and valuable metal in the sintering machine head dedusting ash, solves the problem that the normal production of a blast furnace is influenced by overhigh alkali metal content accumulation, and solves the environmental pollution caused by machine head ash stacking and burning.

The invention discloses a double-vacancy ZnCdS solid solution photocatalyst and a preparation method and application thereof.The preparation method comprises the steps that a cadmium source, a zinc source and a sulfur source are added into absolute ethyl alcohol to be stirred and dissolved, the mass ratio of the cadmium source to the zinc source to the sulfur source is 1: 9: 3, a reaction is conducted under the water bath condition of 70-90 DEG C, suction filtration, washing and drying are conducted, and a powdery ZnCdS solid solution is obtained; the preparation method comprises the following steps: adding NaOH into water, stirring and dissolving, then adding the powdery ZnCdS solid solution, carrying out ultrasonic treatment, and carrying out suction filtration, washing and drying to obtain the double-vacancy ZnCdS solid solution photocatalyst. The preparation method has the advantages of being high in hydrogen production rate, good in repeatability and stability, simple and convenient to prepare, low in cost and the like, the obtained double-vacancy ZnCdS solid solution photocatalyst can be applied to the field of photocatalytic hydrogen production, and the hydrogen production efficiency reaches up to 12.69 mmol.g <-1 >. H <-1 > and is 23.94 times that of pure ZnS and 11.64 times that of pure CdS.

The invention relates to the technical field of biomass-based semiconductor bifunctional materials and environmental restoration, in particular to a Baijiu vinasse biochar / cerium oxide / cadmium zinc sulfur solid solution heterojunction bifunctional material as well as a preparation method and application of the Baijiu vinasse biochar / cerium oxide / cadmium zinc sulfur solid solution heterojunction bifunctional material. The method comprises the following steps: in an inert atmosphere, carrying out pyrolysis on waste Baijiu vinasse to obtain biochar; the method comprises the following steps: mixing biochar and an activator, and carrying out activation pyrolysis in an inert atmosphere to obtain alkali-activated biochar; the preparation method comprises the following steps: dispersing a cadmium source, a zinc source, thiourea, a surfactant, alkali-activated charcoal and cerium dioxide in a solvent to form a dispersion liquid, and carrying out a heating reaction to obtain the Baijiu vinasse charcoal / cerium oxide / cadmium-zinc-sulfur solid solution heterojunction bifunctional material. The adsorption performance of the material is improved due to the remarkable specific surface area of the alkali-activated biochar component; the construction of the cerium oxide / cadmium zinc sulfur solid solution heterojunction significantly accelerates the migration of photon-generated carriers, endows the material with excellent adsorption-photocatalytic performance, has good reusability, and can remove pesticide pollutants in water.

The invention belongs to the technical field of heavy metal pollution treatment, and relates to preparation of a weakly alkaline soil cadmium passivator and a method for passivating soil lead. The alkalescent soil cadmium passivating agent mainly comprises the following components in parts by weight: 20 to 30 parts of graphene oxide modified biochar, 5 to 10 parts of montmorillonite, 5 to 10 parts of bentonite and 5 to 10 parts of a microbial agent, the microbial agent is a composite microbial agent formed by mixing bacillus subtilis, bacillus amyloliquefaciens, bacillus thuringiensis and pseudomonas nitroreducens. The alkalescent soil cadmium passivator has a very good remediation effect on cadmium and lead in polluted soil, can remarkably improve the physicochemical properties of the cadmium and / or lead polluted soil, increase the content of organic matters in the soil, reduce the migration of the soil in the environment and reduce the content of cadmium in crops, and has a great market popularization value.

The invention discloses a multi-component composite material for removing heavy metal cadmium in a water environment as well as a preparation method and an application method of the multi-component composite material. The multi-component composite material is mercaptan modified charcoal-sodium alginate / polyvinyl alcohol composite gel balls; the preparation method comprises the following steps: preparing a turbid liquid composed of a polyvinyl alcohol solution, sodium alginate and mercaptan modified biochar; the cross-linking reaction product of the turbid liquid is the composite gel ball; the multi-component composite material disclosed by the invention is high and stable in removal efficiency of cadmium in water or sediments, and the maximum adsorption capacity can reach 162.45 mg / g; and after a regeneration cycle test, the Cd < 2 + > adsorption capacity can still reach 70% or above of the initial adsorption capacity, so that the Cd < 2 + > adsorbent has good recycling performance and excellent cycle performance.

The utility model belongs to the technical field of crystal growth, and particularly relates to a bearing device for tellurium-zinc-cadmium crystal growth. The utility model discloses a bearing device for growth of tellurium-zinc-cadmium crystals. The bearing device mainly comprises a growth container and a bearing assembly, the growth container is arranged in the bearing assembly; the bearing assembly comprises a base, a connecting shaft and a heat dissipation device. The center of the top of the base sinks downwards; the connecting shaft is arranged in the top sunken area of the base; the diameter of the connecting shaft is consistent with the inner diameter of the base; the growth container is arranged in the heat dissipation device; the bottom of the heat dissipation device is attached to the base and the connecting shaft. The bearing device for the growth of the tellurium-zinc-cadmium crystal is beneficial to the dissipation of latent heat of crystallization generated in the growth process of the tellurium-zinc-cadmium crystal from the bottom, stabilizes a growth interface, eliminates the influence of temperature fluctuation in a heating furnace body on the growth of the crystal, and avoids polycrystals and twin crystals.

The invention discloses a preparation method and application of an iron-manganese modified biochar material for remediation of cadmium and arsenic contaminated soil, and relates to the field of new materials.According to the material, rice hull biochar serves as a carrier, and the specific surface area and surface active sites are increased through programmed intermittent ball milling; and the Fe-O / Mn-O bonding modification complex is formed through gradient loading of iron and manganese oxides. The maximum adsorption capacity of the material to Cd < 2 + > and As (V) reaches 71.54 mg.g <-1 > and 49.30 mg.g <-1 > and is 1.65 / 2.53 times that of original biochar, the content of available Cd and As in soil is reduced by 8.98% and 25.2% under the condition that the addition amount is 0.4%, and the passivation efficiency is improved by 1.05 times (Cd) and 9.08 times (As) compared with that of non-ball-milled iron-manganese modified biochar; the material prepared by the method is applied to cadmium and arsenic polluted soil, pollution can be controlled by waste, and the soil can be effectively repaired.

The invention relates to the technical field of metal purification, and discloses a two-stage rectification purification method of high-purity superfine zinc powder, which comprises the following steps: first-stage rectification is performed on a crude zinc raw material, and a collaborative purification control process is adopted in the first-stage rectification to remove low-boiling-point impurities, so that preliminarily purified zinc liquid is obtained; the collaborative purification control process comprises the steps that first state data of a first rectifying tower are obtained in real time, the future state of the first rectifying tower is predicted based on a first dynamic model, a first optimal control instruction is obtained through online optimization calculation according to a prediction result, and the first optimal control instruction is executed. According to the method, the process tomography technology and the self-calibration dynamic digital twinborn model are combined, real-time and accurate sensing and prediction of the internal fluid dynamic state in the rectification process are achieved, the operation stability of the whole rectification process is remarkably improved, and meanwhile effective separation of cadmium and lead can be achieved.

The invention discloses ZrMn and peanut shell biochar as well as a preparation method and application thereof in adsorption of heavy metal cadmium. The biochar is obtained by loading zirconium oxide and manganese oxide on peanut shell biochar. Compared with a traditional adsorbent, the zirconium and manganese mixed modified biochar has a better removal effect on heavy metals, namely cadmium, Pb and Cu, and can be used for removing the heavy metals in multiple directions. Moreover, after the ZrMn and peanut shell biochar adsorbs heavy metals, the adsorption performance of the ZrMn and peanut shell biochar can be recovered through proper regeneration treatment, and compared with some disposable adsorbents, the ZrMn and peanut shell biochar has higher recoverability and reutilization potential.

The invention relates to the cross technical field of industrial solid waste resource utilization and environmental pollution abatement, and discloses a modified fly ash environmental remediation material as well as a preparation method and application thereof. According to the material, industrial solid waste fly ash is used as a raw material, a glass body structure is destroyed through physical or chemical modification treatment, the specific surface area is increased, active functional groups such as surface hydroxyl groups are enriched, and the adsorption and fixation capacity on heavy metal lead (Pb < 2 + >) and cadmium (Cd < 2 + >) is remarkably improved. The chemical modification adopts an acid solution or an alkali solution, and the preparation method comprises the steps of raw material pretreatment, modification reaction, solid-liquid separation and washing, and drying and screening. When the material is applied to heavy metal contaminated soil remediation, heavy metal in an ion exchange state is promoted to be converted into a stable residue state, the bioavailability and the leaching risk of the heavy metal are remarkably reduced, meanwhile, high-added-value resource utilization of the fly ash is achieved, and the material has environmental, economic and social benefits and is suitable for large-scale remediation of Pb and Cd single or combined contaminated soil.

The invention relates to the technical field of non-ferrous metal metallurgy, in particular to a comprehensive recovery method for low-grade lead-zinc oxidized ore resources. According to the method, through a side-blown smelting furnace oxidation process and a fuming furnace reduction process, firstly, pyrometallurgy oxygen-enriched smelting is carried out, high-lead smoke dust and zinc-germanium-containing slag are produced, zinc oxide smoke dust is obtained through fuming reduction volatilization, then the zinc oxide smoke dust enters a zinc hydrometallurgy process, the high-lead smoke dust enters a pyrometallurgy lead smelting process for batching, and the zinc-germanium-containing slag is obtained. And finally, lead metal (rich in silver), zinc metal, germanium concentrate and tailings are generated. The method aims at achieving comprehensive recovery of low-grade lead-zinc oxidized ore resources by improving the recovery rate of lead and zinc in the low-grade lead-zinc oxidized ore and conducting cooperative treatment on silver, germanium and cadmium at the same time, and a new thought is provided for comprehensive recovery and large-scale industrial production of the low-grade lead-zinc oxidized ore resources.

The invention relates to the technical field of gas analysis, in particular to a determination method for detecting impurity elements in chlorine-nitrogen mixed gas by an ICP-MS (Inductively Coupled Plasma Mass Spectrometry) method. The invention establishes an analysis method for determining the contents of eight elements including iron (Fe), chromium (Cr), copper (Cu), zinc (Zn), nickel (Ni), sodium (Na), cadmium (Cd) and phosphorus (P) in chlorine-nitrogen mixed gas by an ICP-MS (Inductively Coupled Plasma Mass Spectrometry) method. By optimizing ICP-MS analysis conditions and a sample pretreatment process and adopting an electronic-grade solvent to leach elements, rapid and accurate detection and high reproducibility of the impurity content in the chlorine-nitrogen mixed gas are realized. The method can be applied to quality control and analysis in the production process of a chlorine-nitrogen mixed gas product, and lays a foundation for establishing a standard of a chlorine-nitrogen mixed gas analysis method.

The invention discloses a method for jointly recovering zinc and cadmium from zinc-cadmium slag of zinc hydrometallurgy. The method comprises the following steps: S1, carrying out acid leaching on the zinc-cadmium slag and adding zinc powder for replacement; s2, sponge cadmium is subjected to vacuum melting; s3, adding clear water and calcium oxide into the cadmium alkaline residues for wet grinding, filtering to obtain clear liquid and filter residues, and returning sodium hydroxide obtained after the clear liquid is evaporated and crystallized to S2; s4, the filter residues are subjected to reduction roasting, recyclable zinc-cadmium smoke dust, calcium oxide residues and sulfur trioxide are obtained, the calcium oxide residues are returned to S3, sulfuric acid is prepared from sulfur trioxide, and a part of sulfuric acid is returned to S1; the other part of sulfuric acid enters the next step; s5, the smoke dust is dissolved with sulfuric acid, a sulfuric acid solution containing zinc and cadmium is obtained, then zinc powder is added for replacement, and sponge cadmium and a zinc sulfate solution are obtained; the sponge cadmium returns to S2, and the zinc sulfate returns to S1. According to the method, the cadmium alkaline residue treatment product can be effectively recycled and utilized, the cadmium alkaline residue treatment cost is reduced, no cadmium element flows out of the process to cause environmental pollution, and the method is an environment-friendly process method.

A method for preparing a microbial consortium composite remediation agent for synergistic treatment of PAEs and Cd. The preparation method comprises: preparing a functional microbial consortium; preparing a microbial consortium carrier; and preparing the microbial consortium composite remediation agent. In the involved microbial consortium composite remediation agent, the functional microbial consortium is subjected to cadmium-tolerance acclimation, thereby not only exhibiting broad-spectrum degradation activity against PAEs, but also overcoming the issue of reduced degradation efficiency of single functional strains under the stress of heavy-metal Cd pollution in composite contaminated soil. The involved composite remediation agent is modified with sulfhydryl groups, providing excellent passivation effects on heavy metals such as cadmium. In combination with the functional microbial consortium, the remediation agent can achieve the effect of removing PAEs and Cd from the soil synchronously.

The invention discloses a method for efficiently removing heavy metals in soil, which comprises the steps of sample collection, sample pretreatment, supramolecular cage preparation, heavy metal capture, material screening and the like, heavy metals such as mercury, lead, cadmium and the like in the soil are captured through the supramolecular cage, and a magnetic carrier after capturing the heavy metals is removed through a magnetic separation mode; the process flow period is short, the heavy metal removal efficiency is high, no nanoparticle residue risk exists, the long-term leaching risk of apatite, bentonite and other curing agents in a traditional stabilization technology is avoided, environment friendliness is high, and the method is especially suitable for industrial sites, mining areas and other combined pollution scenes and has wide application prospects. And an innovative technical path capable of being popularized is provided for soil remediation.

The invention discloses an iron-carbon composite material for heavy metal contaminated soil remediation and a preparation method of the iron-carbon composite material, and belongs to the field of heavy metal contaminated soil remediation. The iron-carbon composite material comprises rape straw, hydroxyapatite, zero-valent iron, sulfydryl functionalized magnetic cerium oxide and nitrogen-doped graphene quantum dot-sodium alginate. The sulfydryl-functionalized magnetic cerium oxide is prepared from cerium nitrate and ferric nitrate through precipitation, calcination and sulfhydrylation, and the nitrogen-doped graphene quantum dot-sodium alginate is prepared from citric acid and urea through microwave reaction, dialysis, mixing and freeze drying; the preparation method comprises the following steps: treating straws and hydroxyapatite to obtain ball-milled phosphorus-containing biochar, mixing the ball-milled phosphorus-containing biochar with zero-valent iron and two modifiers, and carrying out molding and high-temperature calcination to obtain the phosphorus-containing biochar-based composite material. The material has a remarkable remediation effect on the heavy metal contaminated soil, can effectively reduce the activity of heavy metals in the soil, has the characteristics of environmental friendliness and high stability, and is suitable for treating the soil compositely contaminated by the heavy metals such as cadmium and lead.

The invention discloses a composite photocatalyst for removing uranium in nuclear waste liquid and a preparation method thereof, and the preparation method comprises the following steps: dropwise adding a solution B dissolved with Na2S. 9H2O into a solution A dissolved with CdCl2. 5H2O to obtain a mixed solution; heating the mixed solution for reaction; after cooling to room temperature, centrifuging and washing a product; freeze-drying the washed product overnight to obtain cadmium sulfide; dispersing cadmium sulfide to obtain a suspension; agNO3 is added into the suspension liquid; heating the suspension to react; and washing for several times, and freeze-drying to obtain the silver-loaded cadmium sulfide composite photocatalyst with the cadmium vacancy. The prepared composite photocatalyst is used for adsorption and photo-reduction treatment of radioactive uranium in nuclear waste liquid, and efficient photocatalytic removal of uranium in uranium waste water within the pH value range of 4-8 is achieved. On the premise of being green and environment-friendly, only light and a photocatalyst are needed, pollution to the environment is avoided, operation is easy and convenient, the reaction condition is mild and not harsh, the reaction catalyst can be recycled, and cost is saved.

The invention relates to the technical field of semiconductor materials, and discloses a preparation method of band-gap-adjustable high-quality ZnInGa / CuInS / ZnS / ZnS colloidal quantum well nanocrystals, which comprises the following steps: synthesizing ZIGS quantum dots, mixing a zinc precursor, an indium precursor, a gallium precursor, a sulfur precursor, organic acid, organic amine and 1-octadecene, degassing, and heating to synthesize ZIGS nanocrystals; mixing the ZIGS nanocrystal, organic amine and 1-octadecene, degassing, heating, and injecting a copper, indium and sulfur precursor solution to obtain a ZIGS / CIS nanocrystal; mixing the ZIGS / CIS nanocrystal, organic amine and 1-octadecene, degassing, heating, adding a zinc oleate aqueous solution and the sulfur precursor solution a, reacting, and purifying to obtain the ZIGS / CIS / ZnS colloidal quantum well nanocrystal. And repeating the preparation steps of the ZIGS / CIS / ZnS colloidal quantum well nanocrystal to obtain the ZnInGaS / CuInS / ZnS / ZnS colloidal quantum well nanocrystal. According to the cadmium-free ZnInGa / CuInS / ZnS / ZnS colloidal quantum well nanocrystal prepared by the method, the optimal quantum yield is greater than 99%, and the luminescence peak position is tunable in the range of 533-742 nm.

The invention relates to the technical field of soil conditioners, in particular to a mineral type soil conditioner and a production process thereof. The invention overcomes the problem of insufficient soil fertility caused by enhanced toxic action of cations in soil and insufficient trace elements in soil. By screening the particle size of the fly ash, the adsorption rate of the soil conditioner to the heavy metals in the soil is improved; by controlling the adding amount of the KOH solid powder, the adsorption amount of the modified fly ash to lead and cadmium in the soil is increased; the content of exchangeable aluminum in the soil is reduced by controlling the adding amount of deionized water in the calcined material and the standing and aging time; by roasting the mixture at different temperatures, the content of calcium and magnesium in the soil is increased; by changing the adding parts of the water, the polyacrylamide, the limestone and the montmorillonite, the performance of the soil conditioner for solidifying the trace elements is further improved.