77 results about "Sodium selenate" patented technology

The invention discloses a fermentation medium for regulating and controlling a clostridium aerovorans target product and a fermentation method of the clostridium aerovorans target product. The medium comprises a basic component and a regulating component, the basic components comprise ammonium chloride, potassium chloride, magnesium sulfate heptahydrate, sodium chloride, monopotassium phosphate, yeast powder, calcium chloride dihydrate, sodium selenite, nickel chloride hexahydrate, biotin, folic acid, pyridoxine hydrochloride, thiamine, riboflavin, nicotinic acid, D-calcium pantothenate, cobalamin, para aminobenzoic acid and lipoic acid; the adjusting component comprises sodium tungstate, ferrous sulfate and sodium molybdate, sodium tungstate and ferrous sulfate have a forward adjusting effect on increasing the yield of acetic acid, ethanol and butanol in the target product, and sodium molybdate has a reverse adjusting effect on the target product. By optimizing the proportion of trace elements in the culture medium, the clostridium metabolism efficiency is improved, synthesis of a target product is regulated and controlled, and the method is particularly suitable for industrial production of acetic acid, ethanol, butanol and the like.

The invention discloses a modified biochar material, a preparation method thereof and application of the modified biochar material in treatment of soil pollution, and the preparation method comprises the following steps: carbonizing melon vines or bean vines to obtain biochar; stirring biochar and concentrated nitric acid in an ice bath, then adding distilled water, carrying out heat-preservation stirring, then adding the mixture into an ammonium persulfate solution, and carrying out heat-preservation stirring again, so as to obtain first modified biochar; adding biochar into a calcium solution or an iron solution, and then adding a sodium selenite solution for reaction to obtain second modified biochar; dispersing the first modified biochar and the second modified biochar in distilled water, and adding sodium tetrapolypropylene benzene sulfonate and carboxymethyl cellulose for reaction to obtain the modified biochar material. The biochar material has good physical / chemical stability, can specifically adsorb heavy metals including cadmium, lead and arsenic, greatly improves the adsorption performance on heavy metal ions, improves the adsorption capacity and the adsorption efficiency, and is suitable for heavy metal pollution treatment of mine soil.

The invention relates to the technical field of fertilizers, in particular to charcoal-based nano-selenium as well as a preparation method and application thereof. The preparation method comprises the following steps: putting biochar into a selenium source solution, and adsorbing to obtain biochar adsorbed selenium; and mixing the biochar adsorbed selenium with a reducing agent, and carrying out a reduction reaction under a dark condition to obtain the biochar-based nano-selenium. Biochar is used as a carrier, sodium selenate is used as a selenium source, glucose is used as a reducing agent, and Se < 4 + > adsorbed on the surface of the biochar is reduced into Se < 0 >, so that the novel biochar-based nano-selenium fertilizer is prepared. The biochar-loaded nano-selenium fertilizer can synergistically improve the tomato yield and nutritional quality through multiple mechanisms of enhancing photosynthesis, promoting growth, efficiently enriching selenium elements and the like, and provides a reliable technical approach for developing efficient selenium fertilizers and producing selenium-enriched agricultural products.

The invention belongs to the field of environmental biotechnology and nano material application, and relates to a method for accelerating microorganisms to reduce selenite based on immobilized riboflavin. Aiming at the problems of poor stability, difficulty in recovery, non-repeated use and the like of dissolved riboflavin serving as an electron shuttle, riboflavin is grafted on the surface of a multi-walled carbon nanotube through a covalent binding method, and immobilized riboflavin capable of being recycled is constructed. The material can accelerate extracellular electron transfer of shewanella MR-1, and toxic sodium selenite is efficiently reduced into low-toxicity or non-toxic elemental selenium. Results show that the immobilized riboflavin not only maintains high reduction activity of riboflavin, but also has excellent cyclic utilization performance, still maintains high reduction rate after being repeated for multiple times, and effectively reduces operation cost and resource loss. According to the invention, an efficient, economical and sustainable application scene is provided for a microorganism-electron shuttle combined remediation technology, and a new thought is also provided for application of a functional nano material in an environmental biotechnology.

This invention belongs to the field of waste gas treatment technology, specifically relating to an absorbent for treating organic waste gas and its preparation method. The absorbent for treating organic waste gas comprises the following raw materials in parts by weight: 10-25 parts graphene oxide, 20-30 parts catalyst, 25-40 parts functionalized ionic liquid, and 10-20 parts N-isopropylacrylamide. In the catalyst prepared by this invention, the synergistic effect of the cerium source, cobalt source, and sodium selenate forms a stable heterojunction structure through hydrothermal and thermal treatment processes, optimizing the number and distribution of catalytic active sites and enhancing catalytic oxidation capacity. After oxidation and modification, the graphene oxide enhances its dispersion stability, firmly anchoring the catalyst particles to the graphene surface and accelerating electron transfer in the catalytic reaction. This results in the prepared absorbent for treating organic waste gas possessing high adsorption capacity, efficient catalytic degradation ability, and cycle stability.

The invention belongs to the technical field of pet nutrition, and discloses a trace element composite additive for improving the reproductive performance of pets, which comprises the following raw materials: zinc sulfate, sodium selenite, copper sulfate, manganese sulfate, vitamin E acetate, L-lysine hydrochloride, taurine, methionine, selenium yeast and zeolite powder. The zeolite powder is subjected to a specific acid treatment activation process, so that the adsorbability and the stability are improved. The invention also discloses a preparation method of the additive. A three-step mixing process is adopted to ensure the uniformity of the product. The additive is suitable for being added into feed in the breeding period of canine or feline pets, the adding amount of the additive is 0.1-0.5% of the total weight of the feed, and the feeding time is 1 month before breeding and 1 month after breeding. Through scientific proportioning of organic trace elements and inorganic trace elements, in combination with specific amino acids and vitamins, the components have a synergistic effect, so that the pregnancy rate, the litter size and the survival rate of newborn animals of pets are remarkably increased, and meanwhile, the pet feed has good storage stability and use safety.

According to the red nano-selenium and the preparation method thereof, sodium selenite is used as a selenium source, and ascorbic acid is used as a reducing agent. The reaction medium is impacted by mechanical force in the high-speed crusher and refined, so that the surface area is increased, the reaction is accelerated to achieve a nano effect, and a red nano-selenium mixture is formed. The molar ratio of sodium selenite to ascorbic acid serving as reaction media is increased, the particle size of the nano-selenium is controlled to be 10-50nm, the agglomeration phenomenon of the nano-selenium is reduced, and the stability of the nano-selenium is improved. Ascorbic acid is used as a reducing agent to completely replace traditional toxic reagents such as hydrazine hydrate and thiourea, so that harmful substance residues are avoided. The product can be directly applied without washing, and agglomeration of the nano-selenium material in washing and drying is avoided. Solid-phase mechanochemical reduction is achieved through high-speed smashing equipment, and the strict dependence of a traditional liquid phase on the temperature and the pH value is broken through. The preparation method is low in investment, simple to operate, free of emission of three wastes and suitable for small-batch and industrial production.

The application belongs to the technical field of material preparation, and relates to a bimodal functional imaging nanomaterial and a preparation method and application thereof. 1‑x Fe x Se2, wherein 0 < x < 1. The preparation method of the bimodal functional imaging nanomaterial comprises the following steps: stirring ferrous sulfate and cysteine in a solvent until uniform, then fully stirring bismuth salt, then adding sodium selenite to perform a heating reaction to obtain a bismuth iron selenium nanocomposite. The bismuth iron selenium nanocomposite provided by the application is uniform in size, regular in morphology, has good water phase dispersibility, and has the performance of simultaneously enhancing MRI imaging and CT imaging.

The invention discloses a selenium-rich nutrient solution and a preparation method thereof.The selenium-rich nutrient solution is prepared from, by use amount per mu, 6-10 g of sodium selenite, 80-120 g of monopotassium phosphate, 10-20 g of organic silicon surfactant and 150-250 mL of tea water; alkaline sodium selenite providing a selenium source balances the pH value of the selenium-rich nutrient solution to be neutral under the neutralization of tea water with the pH value of 5-6 and the action of monopotassium phosphate serving as a nutrient component and a buffer solution, so that the selenium-rich nutrient solution can be stored for a long time; the selenium-rich nutrient solution is sprayed on leaves once, and by taking rice as an example, the selenium content in the rice can be increased to 0.5 mg / kg or above, meanwhile, photosynthesis of crops can be promoted, the stress resistance of the crops can be improved, premature senility can be delayed, and the yield can be increased.

The invention belongs to the field of pharmaceutical preparations, and relates to a multi-trace element injection and a preparation method thereof. The multi-trace element injection comprises effective components, a stabilizer and water, the effective components comprise chromium chloride, copper chloride, ferric chloride, manganese chloride, sodium molybdate, sodium selenite, zinc chloride, potassium iodide and sodium fluoride, and the stabilizer comprises xylitol, a pH regulator and an additive; and the additive is PEG (Polyethylene Glycol) 400 or PEG 600. The multi-trace element injection provided by the invention can effectively inhibit the loss of iodine in the sterilization process, and the stability, economical efficiency and production controllability of the multi-trace element injection are fundamentally improved.

Described herein are new compositions comprising a combination of metal(loid)-based antimicrobials (MBAs) that are effective against bacterial biofilms. In embodiments the composition comprises a combination of metal(loid) selected from: a) at least two metals; and b) at least one metal and at least one metalloid. Examples of metal(s) and metalloid(s) useful in the combination include, silver nitrate, potassium tellurite, hydrogen tetrachloroaurate (III), nickel sulfate, copper (II) sulfate, aluminium sulfate, gallium nitrate, sodium selenite, and zinc sulfate. Some combinations are broad-spectrum while others are especially effective against bacterial biofilms resulting from the growth of Gram-negative bacteria or the growth of Gram-positive bacteria. The compositions may be used in methods for disruption and / or of removal of biofilm present on a surface, or for coating purposes thereby providing anti-biofilm activity to a surface.

The invention discloses a regulator for improving grape fruit fragrance and a preparation method thereof, and belongs to the technical field of grape cultivation, each liter of regulator comprises 50 mg-120 mg of chitosan oligosaccharide, 20 mg-50 mg of sodium selenite, 10 mg-20 mg of jasmonic acid methyl ester, 100 mg-250 mg of green tea polyphenol, 10 mg-20 mg of trehalose, 1 mL-5 mL of thymol nanoemulsion, 10 mg-20 mg of beta-cyclodextrin and 0.8 g-1. 0 g of ethyl alcohol, and water is used as a solvent. The content of strawberry ketone, ester and norisoprene compounds in the fruits to which the regulator is applied is obviously increased, nerol and beta-ionone are detected, and the variety of terpene aroma substances is enriched; after the fruit is stored in a high-temperature and high-humidity environment for 3 days, the aroma component change of the fruit to which the regulator is applied is relatively insignificant, and the aroma of the fruit is more stable than that of a reference substance and a blank reference substance.

The application discloses a kind of leaf surface resistance control composite material and preparation method and application thereof, the leaf surface resistance control composite material includes core material with resistance control effect, and shell layer is coated on core material;Wherein, core material is any one of MOFs, sodium silicate, sodium selenate, zinc chloride, ferric sulfate and humic acid;Shell layer is formed by sodium alginate.The shell layer sodium alginate of leaf surface resistance control composite material in the application has affinity with waxy layer of plant leaf surface, prolongs the residence time of leaf surface resistance control composite material on leaf surface, beneficial to the iron ion in leaf surface resistance control composite material into leaf surface tissue, to inhibit Cd in plant tissue migration and transformation, so that Cd only enriches in leaf, reduces the transport to other parts, especially alleviate Cd to grain transport in rice filling period.

The invention discloses selenized lycium barbarum polysaccharide and a preparation method thereof, and belongs to the technical field of structural modification of traditional Chinese medicine polysaccharide. The selenium content of the selenized lycium barbarum polysaccharide is 1.64 mg / g to 7.6 mg / g. The preparation method comprises the step of carrying out selenylation modification on the lycium barbarum polysaccharide by using a nitric acid-sodium selenite system. The anti-stress ability of the lycium barbarum polysaccharide can be remarkably improved, and materials and demonstration are provided for developing novel anti-stress polysaccharide drugs.

The invention discloses a morchella hypha powder prefabrication method and equipment line, belongs to the technical field of morchella hyphae, and solves the problems that morchella is extremely sensitive to continuous cropping, metabolite changes the soil microenvironment, hypha division and nutrient absorption are directly hindered, the hypha growth speed is reduced by 30%-50%, the biomass is reduced, and primordium formation is delayed. Comprising the following steps: S1, carrying out stress-resistant intensified culture on liquid strains; chitosan in a specific proportion in a liquid strain neutralizes dopamine quinone, antioxidant enzyme is induced to be improved, fat-soluble toxin is embedded in beta-cyclodextrin in a solid culture medium, dendrobium nobile residues adsorb water-soluble toxin, sodium selenite enhances oxidation resistance, germanium dioxide promotes hypha branching, an overburden filtrate degrades dopamine quinone, ash hydrolyzes related toxin, and the yield is increased. Pseudomonas compensates for beneficial metabolites and accelerates metabolism through temperature difference stimulation, so that hypha growth is accelerated, differential metabolites are reduced, biomass is increased, and the three-crop fruiting rate is stable.

The invention discloses an erbium-doped zinc selenide composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving zinc nitrate hexahydrate and erbium nitrate hexahydrate in deionized water, wherein the molar ratio of erbium ions in the zinc nitrate hexahydrate is 0.02-0.08; adding sodium selenite and sodium hydroxide; adding a reducing agent hydrazine hydrate; after hydrothermal reaction for h, washing and drying to obtain the erbium-doped zinc selenide composite material. The material is of a cubic phase ZnSe structure, erbium is uniformly doped in crystal lattices, and the material is in a nearly spherical particle shape. Rich 4f electronic defect states are introduced into a ZnSe band gap through erbium doping, charge transfer (chemical enhancement) is remarkably promoted, the free carrier concentration is improved to excite localized surface plasma resonance (electromagnetic enhancement), and the synergistic effect of two enhancement mechanisms is achieved. The detection limit of the SERS substrate to methylene blue is as low as 3.24 * 10 <-8 > mol / L, the enhancement factor is as high as 1.73 * 10 < 4 >, and a new way is provided for environmental pollutant monitoring.

The invention belongs to the technical field of crop cultivation, and particularly relates to a rice aroma-enhancing and yield-increasing agent and application thereof, and the rice aroma-enhancing and yield-increasing agent comprises a primary aroma-enhancing and yield-increasing agent and a secondary aroma-enhancing and yield-increasing agent; the primary aroma and yield increasing agent is jasmonic acid methyl ester with the concentration of 50 [mu] mol / L-100 [mu] mol / L; the formula of the secondary aroma-enhancing and yield-increasing agent is as follows: each liter of the secondary aroma-enhancing and yield-increasing agent contains 0.8 to 1.2 g of ornithine, 25 to 35 mmol of trehalose, 1.0 to 1.4 g of vitamin B1, 1.8 to 2.2 g of vitamin B5, 1 to 3 mg of nano zinc oxide, 4 to 6 mg of sodium selenite, 1 to 3 g of KH2PO4 and the balance of water. The rice aroma-enhancing and yield-increasing agent disclosed by the invention has excellent performance when being applied to three aromatic rice varieties, the 2-AP content is remarkably increased, the yield is kept stable and even slightly increased, and the contradiction between aroma enhancement and yield reduction is successfully solved. The whole set of scheme is synergistic in component, simple and convenient to operate, environment-friendly, good in stability and universality and suitable for large-area production, popularization and application.

The invention belongs to the technical field of selenium fertilizers, and particularly relates to a preparation method of an organic-inorganic compound selenium fertilizer based on soil healthy cultivation, which comprises the following steps: cleaning a porous carrier, depositing sodium selenate and sodium selenite, depositing bacillus on the surface, coating an organic selenium film layer, and finally coating a slow-release film on the surface. According to the invention, the defects of the existing selenium fertilizer are overcome, the sodium selenate and the sodium selenite are matched with the humic acid selenium fertilizer and the amino acid selenium fertilizer to form the organic-inorganic compound selenium fertilizer, and the organic selenium fertilizer and the inorganic selenium fertilizer are stably isolated according to the sequence of adsorption and coating, so that the gradient absorption selenium fertilizer is formed.

The invention belongs to the technical field of waste gas treatment, and particularly relates to an absorbent for organic waste gas treatment and a preparation method thereof. The absorbent for organic waste gas treatment is prepared from the following raw materials in parts by weight: 10 to 25 parts of graphene oxide, 20 to 30 parts of catalyst, 25 to 40 parts of functionalized ionic liquid and 10 to 20 parts of N-isopropylacrylamide, the cerium source, the cobalt source and the sodium selenate in the prepared catalyst have a synergistic effect, a stable heterojunction structure is formed through hydrothermal and heat treatment processes, the number and distribution of catalytic active sites are optimized, and the catalytic oxidation capacity is enhanced; after the graphene oxide is oxidized and modified, the dispersion stability of the graphene oxide is enhanced, catalyst particles are firmly anchored on the surface of the graphene, electron transfer in a catalytic reaction is accelerated, and the prepared absorbent for organic waste gas treatment has high adsorption capacity, efficient catalytic degradation capacity and cycling stability.

The present invention relates to the technical field of microbial fermentation, and discloses a method for producing selenium-rich protein feed by multi-strain co-fermentation of Hami melons. The Hami melons are crushed, then mixed with a carbon source and a nitrogen source, and then inoculated with a fermentation agent for fermentation; the fermented product is dried and pulverized to obtain a protein feed; the fermentation agent includes Candida utilis, Aspergillus niger, and Bacillus licheniformis; the components of the Candida utilis culture medium include yeast extract 9.56 g / L, glucose 19.86 g / L, dipotassium hydrogen phosphate 1.45 g / L, magnesium sulfate 1.12 g / L, sodium selenite 25 mg / L, L-lysine and vitamin B1. In terms of mass concentration, the ratio of sodium selenite, L-lysine and vitamin B1 is 1:(116-232):(0.06-0.12). In the present invention, multi-strain co-fermentation of Hami melons is adopted to obtain a selenium-rich protein feed.

The invention discloses a trace element premix for improving eggshell quality. The feed additive is prepared from the following raw materials: mulberry leaf powder, schizochytrium limacinum powder, eggplant stems, negundo chastetree fruits, negundo chastetree roots, spartina anglica, moringa seeds, chequer-shaped indocalamus leaf powder, tilapia bone meal, crab shell powder, a complex microbial inoculant, compound vitamins, compound amino acids, iron glycinate, ferrous lactate, zinc methionine, zinc propionate, manganese glycinate, copper glycinate, strontium citrate, cobalt methionine, calcium glutamate, sodium selenite and the like. The premix can be used for processing feed for improving the quality of eggshells, is suitable for later laying period of laying hens, and can improve the laying rate and the quality of the eggshells at the same time.

The invention discloses a preparation method of nano-selenium particles. The preparation method comprises the following steps: S1, preparing a wood vinegar fermentation extracting solution which is used for providing an acidic reaction environment for synthesis of the nano-selenium particles and is used as a stabilizer and a morphology regulating agent; and S2, compounding the prepared pyroligneous fermentation extracting solution with ascorbic acid, sodium selenite, sodium carboxymethyl cellulose and cysteine, and carrying out controllable synthesis of nano-selenium particles in a stable system with a multi-component synergistic effect. The invention further discloses application of the obtained nano-selenium particles in selenium nutrient supplements and preparation of foliar fertilizers for selenium-rich agricultural product production.

The invention discloses a boron-free and iron-free foliar fertilizer suitable for plateau wolfberry and a preparation method thereof, and belongs to the technical field of agricultural fertilizers. The foliar fertilizer is characterized in that the foliar fertilizer does not contain boron and iron elements, is rich in manganese, molybdenum and selenium elements, and is mainly prepared from urea, KH2PO4, rare earth nitrate, MnSO4, ZnSO4, KCl, sodium metasilicate, methionine, EDTA, ammonium molybdate, CuSO4, sodium selenite, lithium chloride, cobalt chloride and a liquid solvent according to a specific weight percentage or thousand parts. The liquid solvent is preferably a plateau slaughter house sewage biogas slurry rich in amino acid. The invention also provides a preparation method of the foliar fertilizer, which comprises the following steps: mixing solid raw materials to prepare powder A, taking a liquid solvent as a liquid B, and mixing and dissolving before application. The foliar fertilizer is specially designed for the plateau environment, can effectively solve the problem of lack of pertinence in the prior art, remarkably improves the yield and quality of Chinese wolfberry fruits, reduces the fruit cracking rate and enhances the disease resistance.

The invention provides a bio-fertilizer for promoting plant growth and enriching selenium and a preparation method thereof, and belongs to the technical field of bio-fertilizers, the bio-fertilizer is based on a dried and sterilized mixed organic matter and a direct vat set pantoea inoculant, the mass fraction of N in the mixed organic matter is 4-8%, the mass fraction of P2O5 in the mixed organic matter is 1.6-3.3%, and the mass fraction of K2O in the mixed organic matter is 1.6-3.3%. The selenium-enriched biological fertilizer for promoting plant growth is characterized in that the selenium-enriched biological fertilizer for promoting plant growth is prepared by mixing and fermenting mixed organic matters, calcium superphosphate, sodium selenite and a direct-vat-set pantoea agglomerans fungicide, the pantoea agglomerans AKFX-001 is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC No.36122. The strain disclosed by the invention has the effects of resisting high-concentration selenium, converting inorganic selenium into organic selenium and promoting plant growth at the same time, and a single strain realizes the functions which can be realized by a previous mixed strain, so that the strain has a very good market prospect.

The invention belongs to the technical field of seed cultivation, and particularly relates to a mung bean seed cultivation method based on synergistic treatment of a magnetic field and sodium selenite. The invention provides a magnetic field-sodium selenite mung bean seed treatment method based on time sequence collaboration. The contradiction between efficiency and safety in selenium biological enhancement is effectively solved. Firstly, through low-frequency rotating magnetic field pretreatment, seeds are induced to generate physiological pre-adaptation and activate stress response and metabolic pathways, and a high-capacity buffer environment is created for subsequent low-concentration sodium selenite treatment, so that the selenium absorption and organic conversion efficiency is remarkably improved, and germination and seedling growth are guaranteed while efficient selenium enrichment is achieved. Secondly, the defense network and system for cooperative processing of programmable plants enhance the resistance of seedlings to adverse situations such as drought, low temperature and the like. The whole treatment is completed before germination, field selenium application is not needed, soil pollution is avoided, the treatment liquid can be recycled, the method has the advantages of being environmentally friendly, low in consumption and controllable, and a new way is provided for crop nutrient enrichment.

The invention provides a trace element formula suitable for industrial recirculating aquaculture of penaeus vannamei under an artificial seawater condition and a use method of the trace element formula, and relates to the field of industrial recirculating aquaculture. The trace element formula comprises potassium bromide, boric acid, strontium chloride, sodium silicate, zinc sulfate, ferrous sulfate, copper sulfate, manganese chloride, sodium selenite, ammonium molybdate, calcium gluconate and lysine, and the trace elements are added into a common feed to feed penaeus vannamei boone. The defects in the prior art are overcome, the growth efficiency of the penaeus vannamei boone is effectively improved by supplementing related trace elements in the feed, and the economic benefits of culture are increased.

The invention discloses a rice cadmium-resistant compound foliar spraying agent and an application method thereof. The compound foliar spraying agent comprises the following components: aspartic acid with the concentration of 5-10mg / L; the concentration of the sodium selenite is 50 to 100 mg / L; the concentration of the melatonin is 30-50 [mu] mol / L; and the balance of water. The compound foliar spraying agent is sprayed in the tillering stage, the heading stage and the pustulation stage of rice respectively, and 20-40 kg of the compound foliar spraying agent is sprayed per mu each time. According to the method, multiple cadmium absorption barriers are constructed through the synergistic effect of aspartic acid, sodium selenite and melatonin, the cadmium reduction effect of the brown rice is jointly and greatly improved, the cadmium reduction efficiency can reach 85% or above, all the components are efficient and synergistic, the method is slightly influenced by the environment, and practical significance is achieved.

The invention discloses a rare earth-tungsten cluster bridged polyoxometallate and a preparation method thereof. The chemical formula of the rare earth-tungsten cluster bridged polyoxometallate is [N (CH3) 4] 10.334 H0. 66Na2 [Ln4 (H2O) 10W6O13 (H2MA) 2Ac] [SeW9O33] 4. 86H2O (Ln4Se4W42; ln = Eu < 3 + > and Tb < 3 + >; hAc = acetic acid, and H3MA = D, L-malic acid). The compound is prepared by reacting sodium tungstate dihydrate, sodium selenite and rare earth nitrate in the presence of organic ligand tetramethylammonium chloride, acetic acid and D, L-malic acid. The polyoxometallate material [N (CH3) 4] 10.334 H0. 666Na2 {Eu0. 2Tb3. 8 (H2O) 10W6O13 (H2MA) 2Ac] [SeW9O33] 4}. 86H2O (Eu0. 2Tb3. 8Se4W42) containing double luminescence centers of Tb < 3 + > and Eu < 3 + > is successfully prepared through a rare earth doping method, Tb < 3 + > and Eu < 3 + > respectively provide a strongly changing fluorescence signal and a stable internal reference fluorescence signal, so that a ratio type fluorescence sensor is constructed, and the anthrax bun marker (2, 6-pyridinedicarboxylic acid) in water is detected through the luminous intensity ratio of Tb < 3 + > to Eu < 3 + >. The ratio type sensor has excellent selectivity, sensitivity and anti-interference capability.

This invention provides a nano-selenium, its preparation method, and its applications, relating to the field of nano-selenium fertilizer technology. Using sodium selenate or sodium selenite as raw material A and thiol-functionalized graphene as raw material B, raw material A and raw material B are mixed and reacted for a certain period to obtain nano-selenium, which can be used in fertilizers, food anti-oxidation and preservation, industrial catalysis, or chemical analysis. This invention uses inorganic selenium and thiol-functionalized graphene as raw materials. Through a simple solution mixing, reaction, and settling process, the in-situ reduction of selenite by thiol-functionalized graphene and the stable loading of nano-selenium are achieved, completing the conversion from inorganic selenium to nano-selenium in one step without the need for reducing agents.

This invention discloses a modified biochar material, its preparation method, and its application in soil pollution remediation. The preparation method includes: carbonizing melon or bean vines to obtain biochar; stirring the biochar and concentrated nitric acid in an ice bath, then adding distilled water and stirring while maintaining the temperature, followed by adding the biochar to an ammonium persulfate solution and stirring again while maintaining the temperature, to obtain a first modified biochar; adding the biochar to a calcium or iron solution, and then adding sodium selenite solution to react, to obtain a second modified biochar; dispersing the first and second modified biochar in distilled water, adding sodium tetrapolybenzenesulfonate and carboxymethyl cellulose to react, to obtain the modified biochar material. The biochar material of this invention has good physical / chemical stability and can specifically adsorb heavy metals including cadmium, lead, and arsenic, significantly improving the adsorption performance of heavy metal ions, and enhancing the adsorption capacity and efficiency, making it suitable for the remediation of heavy metal pollution in mine soils.