212 results about "Carbonate Ion" patented technology

The invention relates to the technical field of electrochemical machining, in particular to an electroplate liquid additive automatic supply control method based on conductivity monitoring data. The method comprises the steps that the temperature, the original conductivity and the carbonate concentration of electroplating liquid are obtained, an activation energy coefficient is determined based on the change trend of the original conductivity and the temperature, dynamic thermodynamic decoupling treatment is conducted on the original conductivity, and the net conductivity of the electroplating liquid is generated; according to the cumulative variation of the net conductivity in the historical time period and the total amount of the additive in the historical time period, the transmission inertia factor of the electroplating liquid is calculated in combination with the carbonate concentration, and the retardation risk index is determined based on the evolution trend of the transmission inertia factor, so that a PID control algorithm is reconstructed, and the supply amount of the additive is obtained; and performing automatic replenishment control based on the replenishment amount. According to the method, the accuracy of automatic supply control is improved by evaluating the degradation state of the bath solution components and self-adaptive integral saturation suppression.

The invention relates to a spherical hydrotalcite phase desulfurization adsorbent as well as a preparation method and application thereof, the preparation method comprises the following steps: mixing an iron source, a nickel source and organic carboxylate, and then carrying out hydrothermal carbonization reaction to obtain the spherical hydrotalcite phase desulfurization adsorbent. The nickel source and the iron source are selected as the raw materials, hydroxide radicals of laminates and carbonate ions between the laminates of the prepared hydrotalcite phase desulfurization adsorbent can increase the alkalinity of the surface of the desulfurization adsorbent and improve the adsorption capacity to hydrogen sulfide, and meanwhile, the hydrotalcite phase desulfurization adsorbent can react with hydrogen sulfide in a catalytic oxidation manner, so that the removal efficiency is improved. Organic carboxylate is selected as a hydrothermal auxiliary agent, carboxylate radicals can chelate metal ions through multidentate coordination to form a stable complex, so that the nucleation rate of hydrotalcite is delayed, the particle size uniformity is improved, meanwhile, a carbon coating layer is generated through hydrothermal carbonization, and pores in the carbon coating layer and pores in hydrotalcite can form hierarchical pore channels, so that the composite material is prepared. The mass transfer efficiency is synergistically improved, so that the adsorption capacity of the adsorbent is improved.

The invention relates to the technical field of water treatment, and discloses a method for circularly inducing crystallization, hardness removal and desalination of calcium carbonate. Adding the seed crystal into high salt water; adding sodium hydroxide into the heavy salt water; adding sodium carbonate to generate a supersaturated solution; introducing the solution containing the calcium carbonate crystal nucleus into crystallization equipment; treating the reacted solution through solid-liquid separation equipment; further desalting the water body subjected to hardness removal by adopting a membrane separation mode; collecting and treating the formed calcium carbonate precipitate, and recovering the precipitate by adopting a separation technology; by adopting the synthesized vaterite type seed crystal, the hardness removal and desalination efficiency is remarkably improved in the cyclic induced crystallization process of calcium carbonate. Compared with the traditional non-synthetic seed crystal, the synthetic seed crystal has higher surface area and uniformity, so that the combination of calcium ions and carbonate ions can be more quickly induced to form a stable crystal nucleus, and the overall effect of the reaction is finally improved.

The invention provides a novel D-A-D type fluorescent probe material as well as a preparation method and application thereof. The fluorescent probe material has good stability, the preparation process is simple, and the synthesis condition is mild. Moreover, the D-A-D type fluorescent probe material has good solubility and stability, and a complex of the D-A-D type fluorescent probe material and zinc ions can identify pyrophosphate ions with high selectivity and high sensitivity. The interference of phosphate ions, hydrogen phosphate ions, dihydrogen phosphate ions, fluorine ions, chloride ions, nitrate ions, acetate ions, sulfate ions and carbonate ions is avoided; after the zinc ion complex of the D-A-D type fluorescent probe material is combined with PPi, the fluorescence intensity is remarkably enhanced, the D-A-D type fluorescent probe material has a higher signal-to-noise ratio, in-situ imaging detection of a target object in living cells or tissues is realized, the defects of a traditional molecule and ion detection method are overcome, and the D-A-D type fluorescent probe material is suitable for being widely applied to the field of biological imaging. # imgabs0 #

The invention relates to a method for recovering phosphorus and vanadium from a vanadium-containing salt-removed filter cake, and belongs to the technical field of aluminum oxide preparation. The method comprises the following steps: firstly, preparing vanadium-containing salt elimination filter cake slurry, then adding a dephosphorizing agent into the vanadium-containing salt elimination filter cake slurry, and promoting the dephosphorizing agent to generate precipitation reaction with phosphorus in the slurry to form a precipitate containing phosphorus element, so as to obtain a mixed solution containing the precipitate; next, solid-liquid separation is carried out on the mixed solution, precipitates containing phosphorus elements are filtered out, and the remaining vanadium-containing filtrate is further subjected to impurity removal treatment, so that residual carbonate radicals after the dephosphorization reaction and impurity elements such as arsenic and fluorine in the solution are removed, and adverse effects on the subsequent vanadium precipitation reaction are avoided. And after impurity removal is completed, vanadium precipitation reaction is carried out, and a pure vanadium-containing product is obtained. According to the method, by using the specific dephosphorizing agent, phosphorus in the vanadium-containing salt elimination filter cake is effectively recovered, and the tailing discharge amount is reduced. Meanwhile, the method also improves the concentration of vanadium, is beneficial to the recovery of vanadium, and realizes the simultaneous recovery of phosphorus and vanadium in the vanadium-containing salt elimination filter cake.

The invention provides a method for accelerating carbon dioxide mineralization and sequestration based on a calcium ion-containing aqueous solution, and relates to the technical field of carbon dioxide capture, utilization and sequestration. The method comprises the following steps: selecting a calcium-containing compound, dissolving the calcium-containing compound in water, and uniformly stirring and mixing to obtain an initial aqueous solution; the calcium ion concentration in the initial aqueous solution is within a preset calcium ion concentration range; an alkaline regulator is added into the initial aqueous solution, a target aqueous solution is obtained, and the pH value of the target aqueous solution is within a preset pH value range; injecting the target aqueous solution into formation water of a target formation through injection equipment; carbon dioxide to be sealed is injected into the formation water, and calcium ions in the target water solution and carbonate ions generated after the carbon dioxide is dissolved in the formation water are subjected to mineralization reaction to form calcium carbonate precipitates. According to the method, CO2 dissolution and carbonate conversion are effectively promoted, generation of calcium carbonate precipitates is greatly accelerated, and the key bottleneck of slow reaction kinetics of a traditional mineralization method is overcome.

The invention provides a process for recovering sodium sulfate, sodium carbonate and glaserite in alkali ash and removing chloride ions. The process specifically comprises the following steps: dissolving the alkali ash; sodium sulfate and sodium carbonate in the alkali ash solution are separated through hot crystallization; cooling, crystallizing and separating glaserite in the alkali ash solution; sulfate ions and carbonate ions in the alkali ash solution are separated from chloride ions; and further separating sodium sulfate, sodium carbonate, glauberite and the like in the alkali ash solution. Meanwhile, the invention provides a system for implementing the process. The system comprises an alkali ash dissolving unit, a main crystallization unit, a glaserite crystallization unit, a nanofiltration unit and other elements. According to the process and the system provided by the invention, on one hand, sodium sulfate and sodium carbonate in the alkali ash solution can be extracted, glaserite can be extracted at the same time, chloride ions in the solution are removed at the same time, and the discharge amount of mother liquor is reduced.

The invention discloses a method for preparing a biobrick by using engineering bacteria, and belongs to the technical field of biological building materials. Escherichia coli engineering bacteria capable of generating urease are obtained through engineering modification of escherichia coli, an escherichia coli engineering bacteria solution is mixed with a matching solution containing urea and mineral calcium salt, then sand grains and a hydrogel adhesive are added, and under the appropriate environmental condition, urease generated by the escherichia coli engineering bacteria can catalyze urea decomposition, so that the urea decomposition rate is increased, and the urea decomposition rate is increased. Ammonia and carbonate ions are generated and then react with calcium ions to generate calcium carbonate, so that sand grains are cemented together, and the biobrick with certain strength and biological characteristics is formed. The biobrick not only has good strength, but also has certain self-repairing capability and environmental adaptability, and can be applied to the field of civil engineering as a green and sustainable building material. The preparation method disclosed by the invention is simple, efficient and environment-friendly, has important significance on the national double-carbon strategy, and has a wide application prospect.

The invention discloses a method for converting CO2 into a nitrogen-doped composite carbon material in one step by using molten salt, and belongs to the technical field of carbon material preparation and carbon dioxide resource utilization. The method disclosed by the invention comprises the following steps: S1, mixing LiCl, KCl, KOH and a nitrogen source to form a LiCl-KCl-KOH-nitrogen source system; s2, carrying out first heating and heat preservation on the LiCl-KCl-KOH-nitrogen source system in an inert atmosphere to remove moisture, then carrying out second heating to form molten salt, then introducing CO2 gas to generate carbonate ions, and meanwhile, carrying out electrolysis to obtain a cathode product; and S3, after the molten salt is slowly cooled, taking out a cathode product, and sequentially carrying out washing, vacuum drying and annealing to obtain the gradient nitrogen-doped multilevel structure graphite composite carbon material. The prepared material has multiple nano structures, high specific surface area and high nitrogen content, shows excellent rate capability and long cycle stability in electrochemical energy storage application, and has a wide application prospect.

A carbon sequestration mineral admixture, and a preparation method and device therefor. The method for preparing the carbon sequestration mineral admixture comprises: providing crushed solid waste; providing an activating liquid and a catalytic liquid, one or both of which is optionally in the form of micro-droplets; and contacting and reacting the activating liquid, the catalytic liquid, flue gas containing carbon dioxide, and the crushed solid waste to obtain a carbon sequestration mineral admixture, the contacting optionally being carried out under the action of an external mechanical force, wherein the activating liquid comprises one or more of a magnesium salt, an ammonium salt, an organic amine and a lower alkanol serving as an activating agent, and the catalytic liquid comprises carbonate ions and / or bicarbonate ions serving as a catalyst. The accelerated carbonization method has the advantages of a high carbonization efficiency, simple operation, and also being capable of achieving a high degree of carbonization and significantly increasing the added value of a carbonization product.

The invention relates to the technical field of silver powder synthesis, in particular to a green synthesis process of high-purity silver powder. The silver powder synthesized by the process overcomes the problems of low purity and poor dispersity of the silver powder, and the synthesis process is green. By means of the characteristic that silver ions and carbonate ions generate low-solubility silver carbonate precipitates in the precipitation treatment stage in S1 and in combination with reduction treatment in S2, preliminary purification and further impurity removal are conducted under specific reaction conditions, interference of impurity metal ions is effectively inhibited, and the purity of the silver powder is improved; on the aspect of optimizing the comprehensive performance of the silver powder, a reverse micelle structure is constructed by utilizing various substances in the S2 reduction process, and the growth of silver nanoparticles is regulated and controlled; adjusting the dosage of related substances, illumination and reduction time; controlling synthesis parameters of the tea saponin fatty acid ester; and key parameters are adjusted in the S3 calcination stage, and finally the silver powder is good in specific surface area, average particle size and stability and has good dispersity and pore diameter structure.

The application relates to the technical field of saline-alkali soil improvement, and particularly discloses a preparation process of a multifunctional slow-release type saline-alkali soil improver and application thereof. The preparation process comprises the following steps: (1) uniformly mixing seaweed acid powder, phosphogypsum powder, carbon powder and water to form wet materials, then placing the wet materials in a sealed container for heating and heat preservation treatment, and obtaining a precursor after the treatment; and (2) placing the precursor at normal temperature for standing, crushing the precursor after the standing, and obtaining the soil improver. The soil improver prepared by the above process can not only more efficiently and quickly fix sodium ions, potassium ions, calcium ions and magnesium ions in the soil, but also can reduce the content of carbonate ions, so that the soil salt content and the soil alkalinity are reduced. In addition, the soil improver can help to relieve the phenomenon of soil alkali and salt return, and reduce the usage amount of the improver in the subsequent soil improvement process.

A system and method for acid gas removal are provided. An exemplary system includes a contactor that includes an inlet for an aqueous carbonate stream proximate to a top of the contactor, wherein the aqueous carbonate stream includes a catalyst. The contactor also includes an inlet for a gas stream proximate to a bottom of the contactor, wherein the gas stream includes an acid gas. Further, the contactor includes an outlet for an aqueous bicarbonate-carbonate stream proximate to the bottom of the contactor, and an outlet for a sweetened gas stream proximate to the top of the contactor. The acid gas removal system also includes a nanofilter. The aqueous bicarbonate-carbonate stream is introduced at an inlet to the nanofilter, and a permeate stream from the nanofilter is fed to a flash column. The nanofilter also provides a retentate stream including carbonate ions, wherein the retentate stream is fed to the contactor.

To provide: a production method for powder having reduced specific surface area which enables the powder having reduced specific surface area to be easily produced; and a powder production device.SOLUTION: A production method for powder having reduced specific surface area includes: a reaction step of supplying gas G containing carbon dioxide to a solution 3 containing a metal ion to react the metal ion and a carbonate ion to produce an intermediate 7; and a separation step of separating the intermediate 7 from the solution 3 to produce carbonate mineral powder 2 which is powdered. During the reaction step, a surfactant S for reducing specific surface area of the intermediate 7 is added to the solution 3.SELECTED DRAWING: Figure 1

The invention discloses a preparation method of ferromanganese carbonate for a lithium battery, and relates to the technical field of battery materials. The method comprises the following steps: under the protection of an antioxidant and an inert atmosphere, preparing a mixed metal salt solution from manganese salt and ferrous salt, mixing the mixed metal salt solution with a solution containing carbonate ions, carrying out a co-precipitation reaction, and controlling the reaction temperature, the pH value, the dropwise adding rate, the reaction time and the molar ratio of the manganese salt to the ferrous salt; and filtering, washing and drying the obtained product ferromanganese carbonate in sequence to finally obtain the required battery material ferromanganese carbonate. The method for preparing the ferromanganese carbonate is stable, high in yield and convenient for industrial production, and a product which is uniform in morphology, stable in iron-manganese ratio at 4: 6 and uniform in metal ion distribution can be obtained.

The invention discloses a method for preparing large-particle sodium bicarbonate from sodium sulfate. The method comprises the following steps: pretreating raw materials; dynamically adjusting reaction conditions; establishing a raw material database; carrying out multistage continuous crystallization reaction; heat integration and waste heat recovery; the alkali medium is recycled; the temperature gradient design is simplified; double salt crystal separation and resource utilization, and bicarbonate radical concentration control; strengthening double salt separation by a membrane separation technology; and carrying out solid-liquid separation and product collection. In a sodium sulfate raw material dissolving stage, sodium carbonate or sodium bicarbonate is added to adjust the concentration of carbonate in a solution, so that the concentration is stabilized in a target range, ATR FT-IR is used for carrying out in-situ real-time quantitative analysis on carbonate ions in an aqueous solution, carbonate is automatically supplemented through feedback control, and the content of carbonate ions in the aqueous solution is determined. A plate heat exchanger is installed in a multi-stage reaction device, waste heat of previous-stage reaction liquid is utilized to preheat next-stage reaction liquid, and heat in mother liquor is recovered by adopting a vacuum evaporation technology in salting-out crystallization.

The invention belongs to the technical field of deep-time atmosphere carbon dioxide isotope composition estimation, and particularly relates to a high-resolution deep-time atmosphere carbon dioxide isotope composition estimation method and system, and the method comprises the steps: S100, reconstructing the global surface average temperature based on the atmosphere carbon dioxide concentration pCO2; s200, calculating the relative content of carbonate ions and bicarbonate radical ions in the marine carbonate system; s300, determining a fractionation coefficient; s400, determining a difference value V of carbon isotopes of the carbonatite and surrounding seawater in the carbonatite deposition process on the basis of the carbon isotope difference of the carpopods and the carbonatite; according to the method, carbonate rocks which generally exist in geological history and are continuously deposited on time are selected as a tool for atmospheric carbon dioxide isotope reconstruction, and the atmospheric carbon dioxide isotope is reconstructed through quantitative evaluation of the geological history ocean surface layer temperature, the ocean carbonate rock salt content and the fractionation effect during formation of the carbonate rocks. And the atmospheric carbon dioxide isotope composition in the deep-time geological historical evolution process can be accurately calculated.

Water to be treated (supplied water) (W4) having a pH of 8 or more is supplied to an electrodeionization device (8), and the water to be treated (W4) is supplied to a desalination chamber (25) of the electrodeionization device (8). Then, desalted water (W5) that has passed through the desalination chamber (25) is separated and supplied to the concentration chamber (26) in the opposite direction to the desalination chamber (25). As a result, even if the pH of the water to be treated (water supply) (W4) is 8 or more, the ion concentration in the water to be concentrated in the concentration chamber (26) is lower toward the extraction side of the desalination chamber (25). In particular, the movement of inorganic carbonate ions from the concentration chamber (26) near the outlet of the desalination chamber of the electrodeionization device (8) to the desalination chamber (25) can be reduced, and a decrease in the electrical resistivity of the desalted water (W5) can be prevented. According to this method for operating an electrodeionization device, it is possible to efficiently produce high-quality treated water even if water having a high pH is supplied to the electrodeionization device.

The application discloses a chemical crystallization granulation coupling membrane interface induced crystallization calcium removal system and a calcium removal method, and belongs to the technical field of water treatment. The system comprises a chemical crystallization granulation unit, a membrane interface induced crystallization unit and a microcrystal separation and recycling unit. After preliminary softening of wastewater to be treated by the chemical crystallization granulation unit, the wastewater enters the membrane interface induced crystallization unit, residual calcium ions in the preliminary softening wastewater are enriched in a hydrophilic microzone of the membrane interface, combined with carbonate ions in an induced crystallization reagent, and calcium carbonate microcrystals are generated, the hydrophobic microzone inhibits continuous spreading of the crystals and promotes peeling of the microcrystals; the calcium carbonate microcrystals are separated and concentrated and then recycled to the chemical crystallization granulation unit for recycling. After treatment by the chemical crystallization granulation coupling membrane interface induced crystallization calcium removal system, the concentration of calcium ions in the wastewater is below 10 mg / L. The application realizes calcium removal by coupling of preliminary softening by chemical crystallization granulation and induced crystallization by a membrane, has the advantages of low reagent consumption, recyclable microcrystals and closed-loop operation.

The invention provides a method for synchronously removing suspended matters and hardness ions in water based on biomineralization, which comprises the following steps: high-hardness wastewater and a pre-mineralized urease-producing bacterium liquid are mixed and cultured, the pre-mineralization is to form a calcium carbonate shell on the surface of the urease-producing bacterium, and the urease-producing bacterium can hydrolyze urea to generate carbonate ions and ammonium ions. A mineralized shell is formed through the pre-mineralization process to protect the strain, reduce the influence of pollutants in the environment on the urease activity of the strain, increase the self weight of the strain and promote co-sedimentation of thalli and suspended solids in wastewater, hardness ions in the wastewater are converted into carbonate solid minerals through biological mineralization, removal of the hardness ions is achieved, and the removal rate of the wastewater is increased. Meanwhile, heavy metals and organic pollutants in the wastewater can be removed in the biomineralization process of the urease-producing bacteria. According to the method, synchronous removal of hardness ions and suspended solids in the wastewater is realized based on a biomineralization treatment process, and the method is environment-friendly, low in cost and easy for large-scale application.

The invention provides a positive electrode active material and a preparation method and application thereof, and belongs to the field of batteries. The positive electrode active material provided by the invention comprises layered double hydroxides, and the chemical formula of the layered double hydroxides is [M < 12 + x > M < 23 + y > M < 34 + z > (OH) 2 (x + y + z)] (A < n->) (y + 2z) / n.mH2O, m < 12 + > is a divalent metal cation, M < 23 + > is a trivalent metal cation, and M < 34 + > is a tetravalent metal cation; x is 1-4, y is 0-4, z is 0-4, and (y + z) is 1-4; m = 1-2, and n = 1-3; the interlayer spacing of the layered double hydroxide is equal to that of the positive electrode active material, the material structure stability in the oxidation-reduction reaction process can be maintained, the proper interlayer spacing is beneficial to reversible storage migration and intercalation / deintercalation of carbonate ions, and the electrochemical oxidation-reduction reaction and directional storage and conversion of charges are achieved.

The objective is to provide a method for dissolving solids that is excellent at dissolving solids generated in nuclear facilities. [Solution] A method for dissolving a solid generated at a nuclear facility, comprising dissolving the solid in a solution containing at least one of carbonate ions and bicarbonate ions, and at least one of potassium ions and cesium ions.

The present application relates to the technical field of nuclear fuel cycle, and particularly relates to a method for recycling uranium fluorination wastewater. The method is as follows: adjusting the concentration ratio of bicarbonate and carbonate in the uranium conversion leaching solution, carrying out decolorization and filtration treatment to obtain a filtrate; the filtrate is subjected to uranium adsorption through a resin, and the resin adsorbed with uranium is subjected to leaching; the adsorption tail liquid is added with magnesium hydroxide slurry to adjust the pH to above 11, and then filtered, and the filtrate is adsorbed by amidoamine-based adsorption fiber; the adsorption tail liquid is added with magnesium carbonate slurry to generate magnesium fluoride and carbonate ions, and then filtered to obtain a sediment and a filtrate respectively; the filtrate is returned as a leaching agent of fluorination tail gas or is discharged after treatment; the sediment is used together with new magnesium carbonate to participate in fluorine removal reaction again, and the unreacted magnesium carbonate is used again. The present application realizes efficient recovery of uranium in the leaching solution and recycling of the leaching solution, fully utilizes the residual alkali in the returned liquid, reduces the treatment cost of fluorination tail gas, controls the radioactivity of the waste residue, and realizes radioactivity exemption of the treated sediment.

The application belongs to the technical field of biological medicine, and particularly relates to a kind of composite nanoparticles and its preparation method and application.The composite nanoparticles provided by the application include nano calcium peroxide, hyaluronic acid coated on the surface of the nano calcium peroxide and urease coated on the surface of the hyaluronic acid.In the application, the hyaluronic acid has tumor cell targeting property, which is conducive to accurately delivering the composite nanoparticles to tumor cells;at the same time, the hyaluronic acid can fix the urease on the surface of the nano calcium peroxide, which is conducive to improving the biological mineralization rate.In the application, when the composite nanoparticles enter the tumor microenvironment under the condition of providing urea outside, they are affected by the acidic microenvironment, the nano calcium peroxide decomposes to release calcium ions, and at the same time, the urease specifically decomposes urea in the microenvironment to release carbonate ions, the calcium ions and carbonate ions produce a mineral layer on the surface of the cell membrane through synergistic effect, thereby blocking the channel of cell material exchange and inducing cell apoptosis.

The waste gas treatment method and system based on the metal seawater battery involve electrochemical energy technology and environmental protection technology. The waste gas treatment method of the present invention includes the following steps: (1) introducing the waste gas generated by the near-shore waste gas emission device into the reaction zone of the metal seawater battery; (2) the hydroxide ions generated by the positive electrode of the metal seawater battery react with the carbon dioxide in the waste gas to neutralize the hydroxide ions, and the resulting carbonate ions combine with metal ions to form carbonates to reduce the carbon dioxide content in the waste gas. At the same time, the metal seawater battery outputs electrical energy. The tail gas CO2 capture efficiency of the present invention is high, reaching more than 80%, and at the same time, CO2 resource utilization is realized.

The application provides a carbon dioxide capturing method. The carbon dioxide capturing method comprises the following steps: spraying an alkaline solution through a spraying structure, so that the alkaline solution flowing out of the spraying structure chemically reacts with carbon dioxide gas in a gas to absorb the carbon dioxide gas; buffering the solution after the chemical reaction with the carbon dioxide gas through a buffering structure, and making the solution buffered in the buffering structure flow out through the spraying structure; detecting the concentration of hydroxyl ions and / or the concentration of carbonate ions in the solution in the buffering structure in real time, and supplementing the alkaline solution or water in the buffering structure according to the concentration of hydroxyl ions and the concentration of carbonate ions; if the concentration of hydroxyl ions is less than or equal to m and the concentration of carbonate ions is n, stopping the operation of a circulating pump to make the solution buffered in the buffering structure enter an electrolysis device to be electrolyzed. The application effectively solves the problem that the capturing efficiency of carbon dioxide gas and the overall energy consumption of the carbon dioxide capturing system in the prior art are difficult to control.

The invention relates to the technical field of environmental pollution treatment, and provides a method for treating a heavy metal polluted water body through microorganism induced precipitation, which comprises the following steps: S1, screening a microorganism strain with the capability of efficiently inducing calcium carbonate precipitation from a polluted water body or soil; s2, optimizing culture conditions, including a carbon source, a nitrogen source, pH and temperature, of the strain through a single factor experiment and a response surface method to obtain a high-activity functional strain; s3, inoculating the bacterial suspension in the step S2 into wastewater containing heavy metal ions; s4, bicarbonate or carbonate is added into a reaction system in S3, and carbonate ions are provided; s5, adjusting the pH value of the solution in S4 to 7.0-8.5, and controlling the reaction temperature to be 25-35 DEG C; and S6, forming of calcium carbonate precipitates is induced through a stirring reaction, the reaction time is 2-24 hours, and fixation and removal of the heavy metal ions are achieved.

This invention discloses a method for treating wastewater containing magnesium sulfate and ammonium sulfate. The method includes: evaporating and concentrating the wastewater containing magnesium sulfate and ammonium sulfate, then cooling and crystallizing it, followed by solid-liquid separation to obtain magnesium ammonium sulfate crystals and a mother liquor containing ammonium sulfate; reacting the magnesium ammonium sulfate crystals with an ammonium salt that can generate carbonate ions and water to undergo a precipitation reaction, followed by solid-liquid separation to obtain magnesium carbonate product and a mixed solution containing ammonium sulfate and ammonium carbonate; stripping the mixed solution containing ammonium sulfate and ammonium carbonate to obtain stripped water containing ammonium sulfate and an ammonium carbonate fraction; both the mother liquor containing ammonium sulfate and the stripped water containing ammonium sulfate can be evaporated and crystallized to obtain ammonium sulfate product; the ammonium carbonate fraction can be recycled for precipitation reactions. This invention can effectively separate magnesium and ammonium from wastewater, and the separated magnesium carbonate and ammonium sulfate products have high purity and good quality, and can be used directly as products.

Provided is a carbonate-containing granular material production method with which it is possible to produce a carbonate-containing granular material at a cost lower than when using conventional methods.　The present invention has a carbonation step for bringing, into contact with a carbonation-target granular material at a maximum temperature of higher than 0°C to lower than 100°C, either water, a carbonation accelerator, and at least one among a carbon dioxide-containing substance, a carbonate ion-containing water, and a hydrogen carbonate ion-containing water, or a carbonation accelerator and at least one among a carbon dioxide-containing water, a carbonate ion-containing water, and a hydrogen carbonate ion-containing water. The total amount of water brought into contact in the carbonation step is 1 mass% or more of the carbonation-target granular material. The carbonation accelerator contains bacteria. The bacteria are at least one selected from the genus Bacillus, the family Bacillaceae, the class Bacilli, the family Clostridiaceae, the family Micrococcaceae, the family Microbacteriaceae, or the family Comamonadaceae.

This invention provides a method for efficiently recovering phosphorus using a Mg-Al layered double hydroxide. [Solution] According to one aspect of the present invention, a method for recovering phosphorus contained in wastewater is provided, comprising: a preparation step of preparing a Mg-Al layered double hydroxide having carbonate ions or hydroxide ions as interlayer anions; an exchange step of contacting the Mg-Al layered double hydroxide prepared in the preparation step with a gas containing hydrogen chloride to obtain a Mg-Al layered double hydroxide in which the interlayer anions have been replaced with chloride ions; and a recovery step of contacting the Mg-Al layered double hydroxide obtained in the exchange step with wastewater to replace the interlayer anions with phosphate ions contained in the wastewater and recover the phosphorus contained in the wastewater.