1072 results about "Sulfate radicals" patented technology

The invention relates to an aluminum oxide CMP polishing solution for rough polishing of silicon carbide wafers and a polishing method of the aluminum oxide CMP polishing solution, and the aluminum oxide CMP polishing solution comprises the following components in percentage by weight: 2-10wt% of nano aluminum oxide abrasive; 0.2 to 2 wt.% of a dispersant; 0.001 to 0.01 wt% of a pH regulator; the concentration of the oxidizing agent is 1-5wt.%. By adopting the compound oxidant, potassium permanganate is utilized to oxidize a reduction product manganese dioxide on the surface of the silicon carbide wafer to activate potassium persulfate, so that a large amount of sulfate free radicals are generated in the polishing solution, the oxidability of the sulfate free radicals is extremely high, the polishing solution can be promoted to generate chain oxidation reaction, and the surface of the silicon carbide wafer is further oxidized; and an oxide layer with low hardness is formed on the surface of the silicon carbide and is finally removed under the mechanical action of the aluminum oxide abrasive, so that the ultra-smooth and damage-free surface of the silicon carbide wafer is formed. The surface roughness of the obtained optimal silicon carbide wafer is 0.125 nm, and the material removal rate is 3.5 [mu] m / h. Compared with an existing aluminum oxide polishing solution, the polishing solution has the advantage that the surface quality and the polishing efficiency of the silicon carbide wafer are remarkably improved.

The invention discloses a cementing material for a solid waste-based road of a coal-fired power plant and a preparation method of the cementing material. The cementing material mainly comprises a cementing component, an alkali-activated component and a reinforcing component, the gelling component is a mixture of coal-fired power plant fly ash and furnace slag; the alkali-activated component is a mixture of alkali residues, red mud, blast furnace slag and coal-fired power plant desulfurized gypsum; the reinforcing component is rice hull ash or peanut hull ash. The mass ratio of the gelling component to the alkali-activated component is (4 / 1)-(10 / 1); and the addition amount of the reinforcing component is 1-3% of that of the main body material. The coal-fired power plant solid waste fly ash, the furnace slag and the desulfurized gypsum are used as main bodies, a small amount of other industrial solid waste is added, and the cementing material belongs to a full-solid-waste low-carbon cementing material and can be applied to a road base, a subbase or a base layer. The invention has the characteristics of low carbon emission, high solid waste consumption, simple production process and strong pavement performance, and in addition, the invention has a good stabilization effect on the problem that part of solid waste heavy metals and sulfate ions in a coal-fired power plant exceed the standard.

The invention discloses a nickel-containing etching wastewater treatment process, which belongs to the technical field of environmental protection, and comprises a raw water regulating tank, a pH pre-regulating tank, a heterogeneous catalytic oxidation tower, a neutralization coagulation tank, an inclined tube sedimentation tank and a clean water tank which are connected in sequence. According to the process, under the neutral condition, a catalyst loaded with cobalt manganese oxide is used for activating sodium hydrogen persulfate, high-activity sulfate free radicals are generated, a Ni-EDTA complex structure is fractured in a targeted mode, free nickel ions are released in situ, organic ligands are synchronously mineralized, and the adding amount of sodium hydrogen persulfate is dynamically adjusted through a clean water pool closed-loop control system; and high-purity nickel hydroxide precipitate is generated through alkaline precipitation and coagulation, so that efficient solid-liquid separation is realized. The treatment process disclosed by the invention is compact in flow and stable in operation, effectively solves the problems of difficult complex breaking, low nickel removal efficiency, high sludge toxicity, difficult resource recovery and the like when the EDTA complex nickel wastewater is treated by a traditional method, realizes closed-loop recovery of nickel resources, and has the remarkable advantages of low cost, high efficiency and environmental friendliness.

The invention provides a method, a device and equipment for predicting corrosion current and corrosion of steel bars in concrete in a low-pressure environment, and belongs to the technical field of engineering simulation modeling. The method comprises the following steps: establishing a coupling transmission model in concrete considering oxygen concentration, sulfate ion diffusion behavior and chloride ion diffusion behavior; building a reinforcement corrosion current density and corrosion depth prediction model for predicting the number of charges at different positions of the reinforcement in the concrete, and calculating the corrosion depth and the corrosion product content based on the corrosion current density; and establishing a linear elastic damage model for simulating concrete damage evolution caused by steel bar corrosion according to the corrosion product content output by the steel bar corrosion current density prediction model so as to realize accurate prediction of corrosion and damage. According to the method, oxygen concentration changes under low air pressure are considered, oxygen diffusion is described, output of a transmission model serves as a dynamic variable to be introduced into the corrosion current calculation process, and the accuracy of corrosion current and steel bar corrosion prediction is improved.

The invention relates to the technical field of solid waste treatment, in particular to a method for removing antibiotics and resistance genes in aerobic composting of chicken manure. Comprising the following steps: adding a composting auxiliary material into chicken manure to enable the carbon-nitrogen ratio to be (25-30): 1, and adjusting the initial moisture content to 55-65% to obtain an initial composting material; adding persulfate and zero-valent iron into the initial compost material, and uniformly mixing; loading the mixed material into a container for composting; during the composting period, stirring is performed regularly, and the aerobic composting time is 30-40 days. The method has the advantages that the persulfate advanced oxidation technology and the aerobic composting technology are combined, the potassium persulfate and the zero-valent iron are added to serve as the aerobic composting additive, the zero-valent iron can continuously activate the potassium persulfate, persulfate free radicals and hydroxyl free radicals are generated, and removal of antibiotics and antibiotic resistance genes is promoted; high-concentration oxytetracycline, sulfamethoxazole and ciprofloxacin in the chicken manure are effectively removed; and the abundance of antibiotic resistance genes with high risk levels is obviously reduced.

The invention belongs to the technical field of wastewater treatment, and particularly relates to a composite material as well as a preparation method and application thereof. According to the composite material, blended hydrogel of sodium alginate and polyvinyl alcohol is used as a matrix, zeolite molecular sieves, activated charcoal and zero-valent iron particles are embedded into the matrix to form microspheres, sulfate reducing bacteria are immobilized on the surfaces of the microspheres, the composite material is directly added into a mine water anaerobic reactor, the sulfate radical removal rate exceeds 92%, and the sulfate radical removal rate exceeds 92%. Heavy metals such as Cu, Pb and Cr in the mine water can be synchronously precipitated, and the treatment efficiency and stability of the anaerobic system are remarkably improved.

The invention discloses a softening treatment method for high-calcium and high-sulfate radical sewage. By adding the seed crystal, calcium sulfate is crystallized to achieve the purpose of removing calcium ions, so that the generation of chemical sludge is avoided, and the cost of treating the chemical sludge is further reduced; according to the invention, the seed crystal is selected according to the saturation degree of the sewage, and the dosage of the seed crystal is determined, so that the selection of the optimal seed crystal type and dosage is achieved, the cost is saved, and the purpose of softening water is achieved.

The invention discloses a self-template synthesized linear biochar-based bimetallic material as well as a preparation method and application thereof, and belongs to the technical field of carbon materials. The method comprises the following steps: pretreating ganoderma lucidum residues, and pyrolyzing in a nitrogen atmosphere to prepare charcoal; and mixing the prepared biochar with cobalt nitrate and sodium molybdate to prepare CoMoO4 nanoparticles with in-situ growth of the biochar, and then washing and drying to obtain the BC-coated CoMoO4 linear biochar-based bimetallic material. Heterojunctions formed by binding sites of cobalt-molybdenum bimetal and biochar in the material form more defect sites, the synergistic effect of the metal and the micro-nano fibrous biochar is exerted, the degradation rate in the application of catalytic degradation of bisphenol A can reach 98.18% or above, a multiple reaction mechanism with sulfate free radicals is jointly shown, and the photocatalytic degradation of bisphenol A is realized. And the method has higher adaptability and effectiveness for complex pollutants.

The invention provides an efficient chloramphenicol degradation method based on Co-Cu-carbon composite nano-catalyst activated peroxymonosulfate, which comprises the following steps: regulating the Co / Cu molar ratio in a bimetal organic framework precursor, and performing pyrolysis to prepare the Co-Cu-carbon composite catalyst with an optimized pore structure, graphitization degree and metal dispersity; peroxymonosulfate is activated by utilizing the synergistic effect of Co / Co and Cu / Cu redox pairs to generate sulfate free radicals, hydroxyl free radicals, singlet oxygen and superoxide free radicals, and direct oxidative degradation of chloramphenicol is promoted by taking a catalyst as an electron transfer bridge; the method realizes rapid and efficient removal of chloramphenicol, high mineralization rate, excellent cycle stability and strong anti-interference capability, and solves the technical problems of low removal efficiency, high cost and easy secondary pollution in the prior art.

The invention discloses a preparation method of straw composite nutrient soil, and the straw composite nutrient soil comprises the following components in parts by weight: 40-60 parts of pretreated straw, 15-30 parts of animal manure, 10-30 parts of an inorganic filler and 0.5-2 parts of a microbial agent. The pretreated straw is obtained by carrying out hydrothermal treatment on straw and acid liquor containing sulfate radicals. The straw and the animal manure are comprehensively utilized, the problem of environmental pollution caused by improper disposal of waste can be solved, waste can be turned into wealth, non-renewable resources such as turf are prevented from being added, and the use amount of the fertilizer is reduced. The straw composite nutrient soil is high in water and fertilizer retention performance, the compatibility of all the components is good, the survival rate of plants can be increased, and plant growth can be promoted.

The invention belongs to the technical field of inter-cooling water treatment, and relates to a system and method for cooperatively treating inter-cooling water through multi-stage bypasses. Comprising a gradient filtering unit, a modified adsorption unit and a composite adsorption unit which are sequentially connected, a bottom outlet of the gradient filtering unit is connected with a bottom inlet of the modified adsorption unit; a top outlet of the modified adsorption unit is connected with a top inlet of the composite adsorption unit; the gradient filtering unit sequentially comprises a manganese sand layer and a quartz sand layer from top to bottom; the modified adsorption unit is filled with a coal gangue modified straw biochar material; the composite adsorption unit is internally filled with a microcapsule-embedded calcium alginate-vinasse biochar composite material. According to the invention, three-stage cooperative treatment of iron suspended matter interception, sulfate radical adsorption and iron ion chelation is realized, and low-cost, green and sustainable indirect cooling water deep purification is realized by using the solid waste-based functional material.

The invention discloses a deep fluorine removal agent and application thereof in wastewater in the photovoltaic industry, and belongs to the technical field of fluorine-containing wastewater treatment.The deep fluorine removal agent is obtained by conducting coordination on cross-linked hybrid chitosan microspheres and lanthanum ions to obtain composite microspheres and then synthesizing zirconium-based MOF on the composite microspheres through a hydrothermal synthesis method. The pore channels of the MOF facilitate the passing of fluorine ions but not the passing of sulfate ions, play a certain barrier role, facilitate the enrichment of the fluorine ions on the surfaces of the composite microspheres and the selective adsorption of the lanthanum ions on the fluorine ions, so that the fluorine ions are fixed, and the combination stability of the fluorine ions and the lanthanum ions is greater than that of the sulfate ions. The sulfate ions are in disadvantage when competitive adsorption with the fluorine ions, the selectivity of the deep fluorine removal agent to the fluorine ions is improved, the magnesium ions can be combined with the fluorine ions to generate complexes and can be combined with the sulfate ions to generate soluble magnesium sulfate, and interference of the sulfate ions is reduced through cooperation of the magnesium ions and the sulfate ions.

The invention provides a method and system for recovering phosphate radicals, fluorine ions and sulfate radicals from phosphogypsum washing water step by step, and belongs to the technical field of industrial wastewater resourceful treatment. The method comprises the following steps: (1) adjusting the pH value of the wastewater to 3.0 + / -0.5, adding ferric sulfate according to the molar ratio of Fe to PO4 < 3-> of (1.0-1.5): 1, and selectively precipitating phosphate radicals to generate iron phosphate with the purity of more than or equal to 97%; (2) adjusting the pH value of the first filtrate to 4.7 + / -0.5, adding calcium fluoride seed crystals with the particle size of 50-200mm and CaCl2 (the molar ratio of Ca to F <-> is 0.5: 1-0.6: 1), and carrying out induced crystallization to recover calcium fluoride with the purity of more than or equal to 96%; and (3) adding Ca (OH) 2 (Ca: SO4 < 2-> molar ratio of 1.0: 1-1.2: 1) into the second filtrate, and directionally precipitating sulfate radicals to generate calcium sulfate dihydrate with the purity of more than or equal to 98%. According to the method, the pH and the precipitation sequence are controlled step by step, so that the problem of polyanion competition is solved, the recovery rates of phosphate radical, fluorine ion and sulfate radical respectively reach 98.8%, 96.3% and 97.5%, the content of PO4 < 3-> in purified water is less than or equal to 10 mg.L <-1 >, the content of F <-1 > is less than or equal to 5 mg.L <-1 >, and the content of SO4 < 2-> in purified water is less than or equal to 100 mg.L <-1 >, and the purified water can be directly recycled.

The invention relates to the technical field of concrete crack repairing agents, in particular to a triggered precipitation type concrete crack repairing agent as well as a preparation method and application thereof. The repairing agent is prepared from the following raw materials: sulphoaluminate cement, nano anhydrite with a core-shell structure, fluorine-phosphorus composite seed crystal, magnesium oxide, metakaolin and a water reducing agent, wherein the core-shell structure nano anhydrite is prepared by coating mesoporous silica with nano anhydrite, and the fluorine-phosphorus composite seed crystal is prepared from calcium fluoride and monocalcium phosphate through a hydrothermal reaction. According to the trigger precipitation type concrete crack repairing agent prepared by the invention, sulfate ions are slowly released through the core-shell structure nano anhydrite, the crystal form of ettringite is regulated and controlled through the fluorine-phosphorus composite seed crystal, the problems that a traditional repairing agent shrinks and falls off in the later period, the high-temperature strength is suddenly reduced, and the binding power is insufficient are solved, and the trigger precipitation type concrete crack repairing agent is suitable for concrete structure crack repairing and high-temperature environment engineering.

The invention relates to a method for extracting lithium from a salt lake and synchronously removing silicon and boron. The method comprises the following steps: pre-treating and filtering lithium-containing brine; carrying out reverse osmosis concentration treatment to concentrate lithium to be more than 2.5 g / L; carrying out nanofiltration treatment to remove magnesium, calcium and sulfate ions; treating by adopting an electrodialysis system to obtain a high-silicon and high-boron desalted solution and a low-silicon and low-boron lithium concentrated solution; the low-silicon and low-boron lithium concentrated solution is treated with chelating resin and boron removal resin, so that magnesium and calcium ions are smaller than or equal to 2 mg / L, boron is smaller than or equal to 20 mg / L, and the refined lithium concentrated solution is obtained; concentrating by an evaporation system, adding a precipitant, precipitating, filtering, washing, crushing and demagnetizing to obtain a low-silicon low-boron battery-grade lithium carbonate product. The invention further discloses a system for extracting lithium from the salt lake and synchronously removing silicon and boron, the complex and low-efficiency boron removal and silicon removal nanofiltration process is adopted, and concentration of lithium and efficient removal of silicon and boron are synchronously achieved; silicon scaling pollution caused by membrane separation and heat exchanger tube nests is avoided, and deep removal of silicon and boron is realized.

The invention discloses modified biogas residue-based hydrothermal carbon, a preparation method thereof and a dry digestion method for kitchen waste, and belongs to the technical field of waste organic matter recycling. The preparation method comprises the following steps: soaking biogas residues in a phosphoric acid solution to obtain pretreated biogas residues; mixing the pretreated biogas residues, transition metal salt, biochar loaded with vitamin B12 and water with the mass being 8-15 times that of the pretreated biogas residues, and performing hydrothermal reaction for 1-4 hours under the conditions that the temperature is 180-250 DEG C and the pressure is 1.5-4 MPa to obtain a hydrothermal product; and activating the hydrothermal product for 1-2 hours under the protective atmosphere of 300-400 DEG C to obtain the modified biogas residue-based hydrothermal carbon. The surface Fe-Cu composite oxide sequentially catalyzes and oxidizes H2S into elemental sulfur and sulfate ions, the vitamin B12-loaded biochar can promote MA directional proliferation, the sulfate ions can competitively inhibit SRB substrate uptake, the quantity ratio of MA to SRB is increased, and the methane production efficiency is effectively improved.

A use method of the test device for simulating ion erosion of the PCCP protective layer comprises the following steps: S1, region division: selecting a test object, and firstly dividing the test object into four regions, namely a region I, a region II, a region III and a region IV; dividing each subarea into three test areas, namely a test area A, a test area B and a test area C; s2, making a test plan: executing sulfate ion erosion comparison in a partition I, executing chloride ion erosion comparison in a partition II, executing protective measure comparison in a partition III, and executing a mixed comparison test in a partition IV; s3, making a comparison scheme; s4, making a dry-wet cycle scheme; s5, preparing test conditions; s6, liquid filling is executed; s7, executing a dry-wet cycle; s8, judging whether the dry-wet cycle needs to be ended or not: if Seq is equal to L, ending the dry-wet cycle, and continuing S9; otherwise, indicating that all times of dry-wet cycle treatment is not completed, and returning to S6; s9, extracting a sample; and S10, analyzing a result.

The present invention belongs to the technical field of chemical separation and purification, and specifically relates to a method for removing impurities from a hydroxylamine aqueous solution. The method for removing impurities from a hydroxylamine aqueous solution provided by the present invention comprises the following steps: mixing a hydroxylamine aqueous solution and an alkaline compound for sedimentation and then performing solid-liquid separation to obtain a liquid phase; the alkaline compound comprises barium hydroxide or calcium hydroxide; the liquid phase is passed through an ion exchange column for ion exchange to obtain a purified hydroxylamine aqueous solution; the resin in the ion exchange column is a resin containing phenolic hydroxyl groups. The phenolic hydroxyl-containing resin used in the present invention is easy to obtain, has a wide range of sources, and has low cost. The present invention first uses an alkaline solution to remove sulfate or phosphate in a hydroxylamine aqueous solution, and then uses a phenolic hydroxyl-containing resin to efficiently, quickly, and conveniently remove metal ions in the hydroxylamine aqueous solution without reacting with hydroxylamine. The impurity removal method provided by the present invention has the advantages of simple operation and obvious purification effect, and has good industrial prospects.

The utility model discloses a slaked lime powder on-line feeding and efficient magnesium removal and desulfurization reaction device which comprises a dissolution reaction tank, a slaked lime feeding assembly, a reaction flocculation tank, an overflow pipe, a liquid level meter and a frequency conversion material transfer pump. A water inlet pipe and a powder feeding opening are formed in the top of the dissolving reaction tank; the slaked lime adding assembly is used for adding slaked lime powder into the dissolving reaction tank; the reaction flocculation tank is communicated with the dissolution reaction tank through an overflow port, a feed liquid discharge port is formed in the bottom, and a flocculant filling port and a coagulant aid filling port are formed in the top; the bottom of the overflow pipe extends below the liquid level of the dissolving reaction tank, the top of the overflow pipe is communicated with the overflow port, and the liquidometer is used for monitoring the liquid level value of the reaction flocculation tank in real time; and the variable-frequency transfer pump is used for performing variable-frequency adjustment according to the liquid level value monitored by the liquid level meter. According to the utility model, the problem that only low-concentration magnesium ions, sulfate ions and desulfurization wastewater of suspended matters can be treated by the existing triple box treatment process is solved, and the automation degree is improved.

The invention discloses a method for degrading benzene series in wastewater and inhibiting generation of bromate by electrically activating persulfate. The method is suitable for treatment of bromine-containing water. According to the method, a persulfate electrochemical activation technology is adopted, the current density and the persulfate concentration are controlled, sulfate free radicals (SO4 <.->) and hydroxyl free radicals (HO <.->) generated by an electro-activated persulfate system can effectively degrade benzene series, and meanwhile, effective inhibition on generation of bromate is realized by utilizing a cathode reduction effect; meanwhile, organic pollutants in the water body are efficiently removed. The technology does not need additional reducing agents, is green and environment-friendly, and is suitable for drinking water and industrial wastewater treatment.

The invention provides a method for extracting lithium from sulfate subtype salt lake original brine and application, and belongs to the field of salt lake lithium extraction.The method for extracting lithium from sulfate subtype salt lake original brine comprises the following steps that the sulfate subtype salt lake original brine is subjected to pretreatment and nanofiltration treatment, and low-sulfate-radical brine and high-sulfate-radical brine are obtained; the low-sulfate-radical brine is subjected to desorption after being treated by an aluminum-series lithium adsorbent, and a first desorption solution is obtained; the high-sulfate-radical brine is desorbed after being treated by a titanium-series lithium adsorbent, and a second desorption solution is obtained; the first desorption solution and the second desorption solution are sequentially subjected to RO membrane concentration, multi-stage nanofiltration, electrodialysis concentration, evaporation concentration, resin impurity removal and lithium precipitation treatment, and the battery-grade lithium carbonate is obtained. The nanofiltration treatment is small in operation pressure and low in energy consumption; and the obtained low-sulfate-radical brine and high-sulfate-radical brine are respectively treated by adopting proper adsorbents according to different sulfate radical concentrations so as to efficiently recover lithium, so that the lithium yield is improved, the operation is simple, and the obtained battery-grade lithium carbonate is high in purity and excellent in performance.

The invention provides a method for recycling battery-grade manganese sulfate from manganese-containing feed liquid. The method comprises the following steps: (1) carrying out resin adsorption on a manganese-containing feed liquid to obtain a nickel-cobalt adsorbate and an adsorbed feed liquid; (2) sequentially carrying out extraction treatment and reverse extraction treatment on the adsorbed feed liquid to obtain a solution containing manganese sulfate and an organic phase after reverse extraction; (3) carrying out evaporative crystallization on the solution containing manganese sulfate to obtain battery-grade manganese sulfate; positive ions in the manganese-containing feed liquid comprise manganese ions, nickel ions, cobalt ions, calcium ions and magnesium ions, and negative ions in the manganese-containing feed liquid comprise sulfate ions; an extraction agent adopted in the extraction treatment process comprises an HBL116 extraction agent. According to the method disclosed by the invention, metal oxidation hydrolysis cannot be caused to generate a third phase, the extraction process is stable, enrichment of a high-concentration manganese sulfate solution is realized, high-purity manganese sulfate crystals with qualified impurities are obtained, and efficient recovery of manganese in a high-calcium-magnesium feed liquid system can be realized; and a complicated recovery process is not needed, so that the cost is lower.

The invention relates to the technical field of degradation-resistant organic wastewater treatment, in particular to a cathode and anode type electro-Fenton coupling wastewater treatment device and method.The cathode and anode type electro-Fenton coupling wastewater treatment method comprises the steps that a titanium electrode or a BDD electrode is adopted in an anode module, 0.05-0.5 mol / L sulfate radical serves as electrolyte, and persulfate is electrically synthesized in situ; a cathode module is a porous carbon electrode, and # imgabs0 # is generated through aeration at the speed of 0.5 L / min to 2 L / min; the space between the cathode modules is filled with three-dimensional invasive plant source biochar catalytic particle electrodes, the H-type double-chamber electrolytic tank separates a cathode chamber and an anode chamber through a proton membrane, and the method comprises an intermittent type (firstly adsorbing trace pollutants and then oxidizing, and biochar is renewable) and a continuous type (synchronously adsorbing and degrading high-concentration wastewater, and pretreating to improve biodegradability). The device realizes the cooperation of adsorption and electrocatalytic oxidation, efficiently treats refractory wastewater, promotes the recycling of invasive plants, and has both environmental protection and economic values.

The invention discloses wear-corrosion-resistant high-strength steel for a power transmission tower and a preparation method thereof, and belongs to the technical field of metal materials. The wear-corrosion-resistant high-strength steel for the power transmission tower provided by the invention has good corrosion resistance and wear resistance, has excellent wear resistance in a soil environment of sulfate ions with the concentration of 300 mg / kg-50000 mg / kg and chloride ions with the concentration of 500 mg / kg-10000 mg / kg, and meets various environmental performance requirements of an acid soil environment, an atmospheric corrosion environment and the like. In an acid soil environment, the corrosion resistance is more than 8 times that of plain carbon steel, and the relative corrosion rate is lower than 10%; compared with Q355B, the corrosion rate of atmospheric corrosion resistance is lower than 40%, and the abrasive wear rate is 26.5%-28.0%; and through reasonable matching of corrosion-resistant elements, the requirements of corrosion resistance in various environments are met. The yield strength is 775 MPa-805 MPa, the tensile strength is 952 MPa-985 MPa, the percentage elongation after fracture A50 is larger than or equal to 28%, the low-temperature impact toughness at the temperature of-60 DEG C is larger than or equal to 260 J, meanwhile, the forming performance is excellent, and the 180-degree cold bending requirements that d is equal to 1.0 a are met.

The invention relates to the technical field of hydrometallurgy, in particular to a method for selectively separating calcium sulfate in a complex reaction system. The method comprises the following steps: adding a soluble sulfate solution and a precipitant solution into a base solution in a parallel flow manner, and reacting to obtain mixed slurry containing fibrous calcium sulfate; and separating the mixed slurry containing fibrous calcium sulfate to obtain fibrous calcium sulfate crystals, metal hydroxides and purified liquid. According to the method, on the basis of wastewater treatment through a traditional precipitation method, fibrous calcium sulfate is separated from other substances in a complex system by controlling growth of calcium sulfate crystals, the environmental influence caused by solid waste is reduced while the industrial wastewater containing sulfate radicals is treated at low cost, and finally resourceful treatment of the industrial wastewater is achieved.

The present invention provides a method for preparing silver-coated copper powder, which relates to the technical field of metal powder preparation. This preparation method directly prepares a copper core by chemical reduction method, then uses electroless plating method to grow a silver layer on its surface, and finally uses jet milling to improve the density of the powder. In the present invention, reducing agents with different reduction effects are added twice to reduce copper sulfate, which reduces the initial reaction rate, makes the whole reaction stable, and improves the sphericity of copper crystal nuclei. At the same time, sulfate radicals in the reaction system can form silver sulfate precipitation with silver ions in the subsequent reaction, further slowing down the reduction rate of silver ammonia complex ions and enabling the dense growth of the silver layer. At the same time, the unreacted completely glucose remaining in the reaction system can continue to reduce silver ammonia complex ions when silver ammonia solution is added dropwise later. By strictly controlling the growth rate of silver powder from crystal seeds to particles, the present invention reduces the structural defects caused by rapid growth and improves the performance of the final product.

The invention discloses a method for preparing low-sulfate basic nickel carbonate, and belongs to the technical field of chemical engineering, a three-stage grading washing process is designed through precipitant selection and grading washing processes, each stage of washing has specific purposes and conditions, and particularly, ammonium sulfate and residual sulfate radicals are subjected to competitive reaction in secondary washing, so that the low-sulfate basic nickel carbonate is prepared. The method effectively solves the problem of high sulfate radical content of basic nickel carbonate in the prior art, improves the purity and performance of the product, and has the advantages of simple operation, low cost and the like. The process method has good application prospects and market value and is expected to be widely applied to the field of chemical material preparation.

The invention provides a BDO (1, 4-butanediol) wastewater treatment process with high sulfate content, which comprises the following steps: carrying out electrochemical oxidation treatment on BDO (1, 4-butanediol) wastewater with high sulfate content; introducing the obtained BDO wastewater into an anaerobic reaction device for anaerobic reaction to reduce sulfate ions into hydrogen sulfide and oxidize organic matters to reduce COD (Chemical Oxygen Demand); effluent sequentially flows back to the circulating desulfurization device and the air floatation device; carrying out aeration treatment in the circulating desulfurization device so as to oxidize hydrogen sulfide into elemental sulfur; elemental sulfur is recycled in the air flotation device, and part of effluent of the air flotation device and part of effluent of the anaerobic reaction device flow back to inlet water of the anaerobic reaction device; part of effluent of the air floatation device and part of effluent of the anaerobic reaction device are combined and then are sequentially introduced into an aerobic activated sludge tank with a membrane bioreactor and an ozone catalytic oxidation tank. Effluent can enter a subsequent ultrafiltration reverse osmosis membrane system to be purified, and water produced by the membrane system is recycled as reclaimed water.

The invention relates to the technical field of all-vanadium redox flow batteries, and discloses a supported electrolyte of all-vanadium redox flow battery positive and negative electrolyte and a preparation method thereof, and the supported electrolyte comprises an aqueous solution containing vanadium ions, sulfonate ions, sulfate ions and phosphonic acid groups. The sulfonic acid group (-SO3H) has strong polarity and high ionization degree, after the sulfonic acid group (-SO3H) is mixed with the phosphonic acid group (-PO3H2) and sulfuric acid, the ionic environment of the electrolyte can be optimized, the activation energy of V (II) / V (III) and V (IV) / V (V) electricity on electron transfer is reduced, and compared with an existing sulfuric acid supported electrolyte, the reversibility of electrochemical reaction is remarkably improved, and the electrochemical activity of the electrolyte is enhanced; meanwhile, phosphonic acid groups have high complexing ability, can form stable chelates with vanadium ions and can form complexing-dispersing synergy with sulfonic acid groups, the solubility of the vanadium ions is improved, and agglomeration and crystallization of the vanadium ions are inhibited.

The invention discloses a sustainable purification method based on nanobubbles, and relates to the technical field of water treatment. The sustainable purification method based on the nanobubbles comprises the following steps: preparing a nanobubble solution through a nanobubble generator; mixing the nano-bubble solution with hydrogen persulfate to activate the hydrogen persulfate, and promoting decomposition of the hydrogen persulfate on a nano-bubble interface to generate free sulfate radicals; the peroxydisulfate is used for water treatment and purification after being activated. By means of the innovative structural design and the utilization of the characteristics of the nano bubbles, the oxidative degradation efficiency is improved, meanwhile, the purification capacity can be kept as long as several months, low-energy-consumption, pollution-free and sustainable green environment restoration is achieved, and an efficient, environment-friendly and economical new way is provided for water pollution treatment.