52 results about "ARSENATE ION" patented technology

The invention relates to a cellulose base/Fe3O4 composite adsorption material used for removing arsenic in water and a preparation method thereof. According to the invention, with fibers or powder of natural cellulose or fibers of a cellulose derivative as a cellulose matrix material for the composite adsorption material, in an alkaline water system provided by ammoniacal liquor, Fe3O4 particles are loaded on the surface of the cellulose matrix material through in-situ co-precipitation, and the loaded Fe3O4 particles enable the obtained cellulose base/Fe3O4 composite adsorption material to have magnetism and to be easily removed from water, and allow harmful ions like arsenate ions and arsenite ions in water to be absorbed. Compared to arsenic removal materials in the prior art, the invention has the following characteristics: a natural biomass is used as an adsorption carrier, and the natural biomass is cheap and highly efficient, enables the content of arsenic in water to be substantially lower than a national standard and is easy to remove and convenient to use.

The invention discloses a chitosan and chitosan quaternary ammonium salt composite magnetic microsphere and a preparation method thereof. The method comprises the steps of preparing a water phase, stirring and dissolving chitosan, chitosan quaternary ammonium salt and a pore-foaming agent PEG or PVP according to a ratio in an acetic acid aqueous solution, and adding magnetic particles for stirring and ultrasonic treatment; preparing an oil phase, and stirring liquid paraffin and Span80 to obtain the oil phase; gradually adding the water phase into the oil phase drop by drop while stirring is carried out to obtain a liquid mixture; adding a sodium polyphosphate aqueous solution into the liquid mixture drop by drop, carrying out stirring, and adding a glutaraldehyde aqueous solution for reaction; carrying out centrifugation and washing to obtain the chitosan and chitosan quaternary ammonium salt composite magnetic microsphere. The composite magnetic microsphere disclosed by the invention is higher in adsorption to electronegative materials such as humic acid, anionic dyes, arsenate ions, phosphate anions and nitrate ions, is higher in pH adaptability, magnetic separation property and regeneration performance, and is high in exchange capacity, high in adsorption speed and easy to separate.

The present disclosure provides methods, recombinant DNA molecules, recombinant host cells containing the DNA molecules, and transgenic plant cells, plant tissue and plants which contain and express at least one phytochelatin biosynthetic coding sequence under the regulatory control of the strong ACT2 constitutive promoter or the light-inducible SRS1 promoter and/or a plant-expressible arsenate reductase coding sequence. Optionally the plant expressing the at least one phytochelatin biosynthetic enzyme coding sequence can also express a mercuric ion reductase coding sequence. The transgenic plants are tolerant of heavy metal ions, e.g., cadmium, arsenate and/or mercury, and can accumulate those ions from a contaminated environment, to thus, effect phytoremediation of a contaminated soil or water environment which contains mercury, cadmium and/or arsenate ions.

This invention relates to a method for preparing magnetic iron oxide/nanoscale zeolite molecular sieve composite. The method comprises: (1) selecting nanoscale zeolite crystal material; (2) introducing Fe2+/Fe3+ as active reaction sites through ion exchange under the action of electrostatic attraction; (3) dropping 25% ammonia solution for reaction of the active sites in an alkaline medium, washing with water and drying; (4) removing phosphate ions and arsenate ions from water by using a dynamic adsorption apparatus. The method has such advantages as low cost, simple operation and high adsorption rate, and can be widely used for water purification.

The invention provides a method for removing arsenate ions in waste water according to magnesium-iron binary hydrotalcite, which belongs to the field of water treatment adsorption of environmental protection. The Mg2Fe-LDHs adsorbent is prepared in a co-precipitating manner. Under the room-temperature condition, the adsorbent is added into a waste water solution according to a mass ratio of the adsorbent to the arsenate negative ions in the waste water being (0.16 to 8) to 1 and stirred for one hour, so that the adsorption balance can be achieved. The adsorption capability of the adsorbent forthe arsenate negative ions can reach 415 mg/g. The method has the advantages of low cost, simple process and good treatment effect.

The invention discloses an arsenic sulfide waste residue recycling treatment method, which comprises the following steps: performing alkaline leaching to obtain sulfo-arsenite or sulfo-arsenate solution, filtering to remove waste residues through a filter, to obtain alkaline leachate, then performing oxidation desulfurization, so as to oxidize sulfo-arsenite or sulfo-arsenate into sulfo-arsenite or arsenate ions, then filtering and separating elemental sulfur through another filter to obtain arsenite or arsenate solution, recovering acid-base from the arsenite or arsenate solution by utilizing a bipolar membrane device, returning base solution for alkaline leaching and acid solution for crystalization and preparation of As2O3 or As2O5, performing electrodialysis or reverse osmosis concentration on residual liquor in a bipolar membrane salt chamber, returning concentrated liquor as inflowing water of the salt chamber of the bipolar membrane device, and draining or recovering fresh water. According to the arsenic sulfide waste residue recycling treatment method, the problems that for the traditional arsenic sulfide waste residue treatment method, consumption is large, the content of arsenic in effluent water does not reach the standard, the recycling rate is low, the technological process is complicated, secondary pollution exists and the like can be solved, the content of arsenic in effluent water reaches the standard, the recycling rate of As and S is high, the advantages of low consumption, low running cost, simple technological process and the like can be achieved.

The invention provides a method for preparing an arsenic adsorbent. The arsenic adsorbent has zirconium oxide of nano-pore structure. The material can effectively treat arsenate and arsenite in the waste water, and can be recycled after waste water treatment. Another objective of the invention is to provide a method for treating waste water containing arsenate or arsenite ions by the arsenic adsorbent prepared by the method. The method contains a 'regeneration' step, so that the arsenic adsorbent can be reused cyclically.

The invention discloses an arsenic removing water purification treatment method and belongs to the technical field of water purification treatment. Arsenic in water exists in two main valence states including tervalence (arsenite ions) and pentavalence (arsenate ions), wherein the pentavalent arsenic can be removed by an iron salt flocculating agent, but the tervalent arsenic cannot be removed by the iron salt flocculating agent. According to the process, potassium hypermanganate is used for pre-oxidizing, and the iron salt flocculating agent and an auxiliary flocculating agent are added together; the arsenic in raw water is removed by a coagulant sedimentation method; finally, tiny floc, which is not settled and is adsorbed by the flocculating agents, is further intercepted by quartz sand filtering or an immersing type ultrafiltration membrane, so that the content of the arsenic in the output water reaches 0.1 microgram per liter.

The invention discloses a core-shell SERS (surface enhanced Raman spectroscopy) probe, a method for preparing the same and application of the core-shell SERS probe to trace arsenate ion detection, and belongs to the technical field of drinking water safety detection. The method includes the steps: concentrating 5-20 mL of citrate-stable precious metal nano-particle colloidal solution by the aid of centrifugal separation processes until the volume of the citrate-stable precious metal nano-particle colloidal solution is 1.5-3% of the original volume of the citrate-stable precious metal nano-particle colloidal solution so as to obtain concentrated solution; dispersing the obtained concentrated solution into 2-5 mL of organic alcohol solvents, sequentially adding 0.5-2 g of sodium acetate and 0.01-0.05 g of iron salt into the organic alcohol solvents, then strenuously stirring the sodium acetate, the iron salt, the concentrated solution and the organic alcohol solvents and completely dissolving reactants to obtain mixtures; carrying out hydrothermal reaction on the mixtures under the condition of the temperature of 180-250 DEG C for 8-18 h to obtain precious metal @Fe3O4 core-shell nano-particles. The core-shell SERS probe, the method and the application have the advantages that physical and chemical characteristics of precious metal cores and Fe3O4 shell layers can be effectively integrated on the core-shell SERS probe, and arsenate ions can be adsorbed by the Fe3O4 shell layers and accordingly can be effectively enriched on the surface of precious metal; the limit of detection of the arsenate ions of the core-shell SERS probe can be obviously lowered, and the core-shell SERS probe and the method can have important application prospects in the field of drinking water safety detection owing to magnetic separation and desorption recycling.

The invention relates to a method for treating arsenic pollutants with a calcic aluminiferous material, belonging to the technical fields of waste material recycling and arsenic pollutant stabilization. The calcic aluminiferous material used as a stabilizer contains abundant calcium and aluminum: in the arsenic pollutant stabilization process, the calcium directly precipitates with (AsO4)3<->; the (AsO4)3 intercalation forms hydrotalcite-like calcium aluminum-LDH and surface adsorption action with calcium and aluminum in the system; and under the coagulation precipitation actions of the aluminum ions on the arsenate radical, the goal of arsenic pollutant stabilization is achieved. The method comprises the following steps: taking a certain amount of arsenic pollutants, dispersing the arsenic pollutants in a water solution, and adding the calcic aluminiferous material, wherein the dry weight proportion of the calcic aluminiferous material to the arsenic pollutants is 1:10-1:20; and oscillating at room temperature for 12-24 hours, standing for aging, filtering, and carrying out solid-liquid separation. The stabilizer calcic aluminiferous material is cheap, accessible and stable, is used for arsenic pollutant stabilization, and has important economic, environmental and social meanings.

A laminar material for cleaning the anion-polluted water by removing the anions (F ions, arsenous radicals, or arsenic radicals) is prepared through proportionally dissolving Mg (or Zn) source and Al source in water, dissolving alkali and anions in water, quickly mixing them, stirring for 48-144 hr, pump filtering, water washing and baking to obtain white powder.

The invention discloses a method for treating high-concentration alkaline arsenic mining and metallurgy wastewater by coprecipitation-ion exchange compound technology, belonging to the technical field of wastewater treatment. The method comprises the following steps: (A) controlling the raw water of the arsenic mining and metallurgy wastewater to flow into a pH regulating tank, and regulating the pH of the raw water; (B) adding a mixture of ferric chloride and calcium chloride as well as polyacrylamide to carry out coprecipitation reaction; (C) enabling the coprecipitation reaction mixed liquid obtained in the step (B) to flow into a precipitation tank to undergo solid-liquid separation; (D) passing the supernatant obtained in the step (C) through an adsorption tower filled with nanocomposite materials; (E) stopping adsorption when the arsenate ions adsorbed by the nanocomposite materials reach the breakthrough point, and desorbing and regenerating the nanocomposite materials; (F) concentrating the desorption liquid obtained in the step (E), and then sending the precipitate outwards for incineration or reducing the precipitate for producing pesticides. The method can be used for advanced treatment of the high-concentration alkaline arsenic mining and metallurgy wastewater, and has good treatment effects.

The invention discloses macroporous weak-base anion-exchange resin and a preparation method thereof. The macroporous weak-base anion-exchange resin comprises the following components: an oil phase anda water phase, wherein the oil phase is 60-80 parts of a 2-vinylpyridine monomer, 25-35 parts of a divinylbenzene cross-linking agent, 100-150% of polyurethane and modified hydroxymethyl cellulose asa mixed pore-foaming agent by monomer weight, and 1.5-3% of benzoyl peroxide and azodiisobutyronitrile as a mixed initiator by monomer weight; and the water phase is 480-600 parts of deionized water,2-3 parts of a hydroxypropyl methyl cellulose dispersing agent, and 38-42 parts of a sodium nitrite salting-out agent. The preparation method thereof comprises the following steps: adding the oil phase to the water phase, stirring, varying a temperature, and performing a curing reaction. The prepared macroporous weak-base anion-exchange resin has higher adsorptive selectivity, larger adsorptioncapacity and good heat resistance, and is capable of efficiently removing harmful or degradation-resistant anions of an arsenate ion, an aromatic sulfonate ion, a fumaric acid radical ion and the like, and prolonging service life thereof.

The invention discloses a resourceful treatment method of industrial wastewater containing chlorine and arsenic. The method comprises the following steps: adding a preset amount of adsorbing materialinto a wastewater solution, and starting heating operation and stirring operation at the same time; filtering out the adsorption residues in the stirred solution; adding a preset amount of sulfuric acid into the filtered solution, adding a preset amount of the adsorbing material again, and starting heating operation and stirring operation at the same time; filtering out the adsorption residues inthe stirred solution; detecting the concentration of chloride ions and/or arsenate ions in the filtered solution, and judging whether the detection result meets the treatment requirement or not; whenthe detection result meets the treatment requirement, recycling the filtered solution or discharging after reaching the standard; collecting the adsorption residues in the previous step, adding a preset amount of desorption solution, and stirring while adding an alkaline material until the pH value is kept alkaline and does not drop any more; and filtering out the desorbed and regenerated adsorbing material so as to realize the cyclic utilization of the adsorbing material.

The invention relates to a method for recovering valuable elements from gold-containing sulfur concentrate roasting slag pickle liquor, and belongs to the field of chemical beneficiation. The method comprises the following steps that (1) the contents and acidity of copper, zinc, iron, arsenic and sulfate radicals in acidic waste liquor are measured; (2) calcium carbonate or lime is added, concentrating and filtering are carried out to obtain a gypsum product and an acidic solution; (3) an oxidizing agent is added, then a sodium hydroxide solution is added, the pH value is 2.7-3.7 after the slurry reaction is finished, and arsenic-containing iron ore concentrate and copper-zinc-containing filtrate are obtained through concentration and filtration; (4) an arsenic precipitator is added, reacting is carried out for 30 minutes, concentrating, and filtering are carried out to obtain copper-zinc concentrate and acid-containing waste liquid; (5) the concentration of ore pulp is adjusted to be 50%, a sodium hydroxide solution is added, and then filtering and washing are carried out to obtain iron ore concentrate and arsenate-containing alkali liquor; and (6) sulfuric acid is added, the pH value of the solution is adjusted to 1, then the arsenic precipitator is slowly added, and then concentrating and filtering are carried out to obtain arsenic concentrate and acid-containing waste liquid. The arsenic-containing wastewater can be treated, and valuable elements in the arsenic-containing wastewater can be recycled.

The invention relates to the technical field of arsenic removal of anhydrous hydrogen fluoride, in particular to a process for removing arsenic in the process of preparing anhydrous hydrogen fluorideby a fluosilicic acid method, which comprises the following steps of: 1, pre-purifying fluosilicic acid; 2, pre-oxidizing trivalent arsenic in fluosilicic acid; 3, carrying out further catalytic oxidation on trivalent arsenic by using microporous filtration II hydrogen peroxide; 4, treating the materials with a concentration and reaction system; 5, screening silicon dioxide; 6, gasifying and decomposing the material; 7, treating the material through a hydrogen fluoride reboiling system and a drying separation system. The method has the beneficial effects that hydrogen peroxide and manganese dioxide can be added as catalysts under the conditions of normal temperature and acidity to oxidize arsenic in fluosilicic acid into pentavalent arsenic; since a small amount of trivalent arsenic cannotreact with hydrogen fluoride to generate arsenic trifluoride difficult to separate under the condition that the boiling point of arsenate is 160 DEG C, the oxidation operation and cost are low, large-batch production is facilitated, and the obtained anhydrous hydrogen fluoride is high in purity and small in harm.