77 results about "Oxygen limited" patented technology

The invention discloses an environmentally friendly biochar-based fertilizer and an application method thereof. The preparation of the biochar-based fertilizer comprises the following steps of: drying and crushing forestry and agricultural residues, then performing oxygen limited pyrolysis on the crushed materials for 1-5 hours at 300 to 700 DEG C, and sieving, thereby obtaining biochar; and after the biochar is fixed with persistent organic pollutant degrading bacteria, mixing the biochar with a fertilizer, stirring the two thoroughly, and adding a binder accounting for 1wt%-4wt% of the total weight, thus obtaining the environmentally friendly biochar-based fertilizer. For application, the prepared environmentally friendly biochar-based fertilizer is applied to soil by 100-1000 kg per hectare; the surface layer of soil, to which the biochar-based fertilizer is applied previously, is turned over by 0-20 cm, so that the biochar-based fertilizer is mixed with the soil thoroughly, and then the soil can be used for planting crops. The environmentally friendly biochar-based fertilizer provided by the invention overcomes the shortcoming that present biochar-based fertilizers contain organic pollutants such as polycyclic aromatic hydrocarbon, the influence of the fertilizer on soil and environment is alleviated, and the safety risk of agricultural products is reduced; moreover, the environmentally friendly biochar-based fertilizer has the advantages of simple and practicable preparation process, low cost and the like.

The invention relates to aerobic denitrifying paracoccus denitrificans and application thereof. A bacterial strain provided in the invention is paracoccus denitrificans DN-3CGMCC No. 3658; the Paracoccus denitrificans can carry out aerobic denitrification by using nitrate nitrogen under both aerobic and oxygen-limited conditions and can also carry out heterotrophic nitrification-aerobic denitrification by using ammonia-N, and a total nitrogen removal rate on above mentioned occasions is greater than 90%. The paracoccus denitrificans provided in the invention has stable hereditary features, isapplicable to treatment of a variety of nitrogen-containing waste water and produces a good nitrogen removal effect.

The invention relates to a preparation method of biomass-based magnetic biochar. According to the preparation method, forestry and agricultural waste materials are taken as raw materials; biochar prepared via oxygen-limited pyrolysis or hydrothermal carbonization is taken as a substrate; magnetic nano-material Fe3O4 is obtained via iron precursor pyrolysis, loading of magnetic nano-material Fe3O4 onto the biochar substrate is realized in a polyhydric alcohol solution, and an obtained product is subjected to sintering under nitrogen protection so as to obtain stable magnetic nano particles with high crystallinity. Compared with existing technology, loading of in-situ synthesized Fe3O4 onto the surface of biochar is realized via pyrolysis; reaction selectivity and efficiency are high; size of the Fe3O4 nano particles and loading area on the surface of biochar are controllable; and operation is simple and convenient.

A starting and running method of a completely autotrophic ammonium removal over nitrite technology belongs to the water environment recovery and regeneration fields. The starting and efficient and stable running method of the completely autotrophic ammonium removal over nitrite (CANON) technology in a biofilter reactor at normal temperature comprises the following steps: inoculating sludge, carrying out filter material film forming under an anaerobic and anoxic condition, starting CANON under an oxygen limited condition, and controlling the hydraulic retention time and the aeration rate in a combined mode to realize the high-load stable running. The CANON technology is started within 61d, the total nitrogen removal load in the 42d running after starting reaches 3.52kg.m<-3>.d<-1>, and the load is an extremely high level in the research field of the CANON technology, so the method has a simple operation, is easy to implement, and can realize the effective and rapid starting and the high-load running of the CANON technology.

The invention provides a preparation method for lamellar porous biocarbon with a good adsorption function. The objective of the invention is to overcome the problems of difficulty in degradation, proneness to migration and great harm during treatment of pesticides in water bodies in the prior art. The method comprises the following steps: 1, carrying out cleaning; and 2, uniformly mixing biomass powder with chlorine atom-containing low-melting-point molten salt, then carrying out high-temperature oxygen-limited carbonization, cleaning a calcination product and then successively carrying out grinding and sieving so as to obtain the lamellar porous biocarbon. According to the invention, when 15 mg of the lamellar porous biocarbon prepared in the invention is used for adsorbing 40 mL of an aqueous atrazine solution with an atrazine concentration of 25 to 150 mg/L, the residual amount of atrazine is less than 10% while the residual amount of atrazine in a blank control group of an aqueous atrazine solution is 80%. The preparation method provided by the invention is applicable to preparation of lamellar porous biocarbon.

The invention provides a step-feed multistage A/O-MBR processing method for oil shale retorting waste water, and comprises the following steps: (1) the oil shale retorting waste water is introduced with a step-feed multistage A/O-MBR processing system; the waste water is divided into three portions and enters into three anoxic pools respectively; (2) denitrification reactions are carried out in each anoxic pool; (3) waste water enter into each aerobic pool, and nitrosation reactions and nitrification reactions are carried out in each aerobic pool; (4) the waste water enters into a membrane bioreactor; (5) clear water generated after filtering by the membrane module is discharged, and a retained sludge mixed liquor returns to the first anoxic pool. According to the invention, oxygen-limited aeration is carried out in the first aerobic pool and the second aerobic pool, thereby realizing short distance nitrification; by means of step-feed, COD in the original water can be fully utilized for denitrification, thereby reducing external carbon source adding amount and mixed liquor reflux ratio, and reducing aeration cost and denitrification required carbon source.

The invention belongs to the technical field of biochar materials and discloses iron modified peanut shell magnetic biochar as well as a preparation method and the application thereof. The preparationmethod comprises the following steps: taking peanut shells and ferric trichloride as raw materials, magnetizing by a method for soaking peanut shell biomass with a ferric trichloride solution, and performing oxygen limited thermal pyrolysis, so as to obtain the product. The iron modified peanut shell magnetic biochar is applied to an aqueous solution containing hexavalent chromium, the solution is overturned and oscillated at a room temperature, the iron modified magnetic biochar is separated from the solution after the reaction is completed, and aims of removing the hexavalent chromium in the water and separating and recovering the adsorbent are achieved. The method disclosed by the invention has the advantages of being low in cost, simple and convenient to operate, high in treatment efficiency and the like. Moreover, the adsorbent is wide in raw material source, the resource utilization of the biomass is realized, and the biochar has magnetism, is convenient to separate, recover andrecycle, does not cause secondary pollutions, and can be applied to treatment of industrial wastewater containing hexavalent chromium in electroplate factories, tannery factories, smelting plants andthe like.

The invention discloses a phosphorus diffusion method of a silicon solar battery. The phosphorus diffusion method comprises the following steps: (1) placing a silicon wafer to be treated in a diffusion furnace and heating to 780-810 DEG C; (2) heating to 810-870 DEG C, and after the temperature is stable, introducing nitrogen carrying a phosphorus source and dry oxygen at the same time so as to carry out constant-source diffusion, wherein the flow of the nitrogen carrying a phosphorus source is 1-1.7L/min, the dry oxygen flow is 0.4-0.7L/min, the phosphorus source is phosphorus oxychloride, and the temperature of the phosphorus source is constant at 12-20 DEG C, so the surface concentration of phosphorus impurities on the surface of the silicon wafer is (1.0e+21)-(1.3e+21)cm<-3>; (3) keeping the diffusion furnace temperature and the dry oxygen flow unchanged, stopping introducing the nitrogen carrying a phosphorus source, and carrying out oxygen limited-source diffusion; and (4) cooling, and pulling out a quartz boat, thus finishing the diffusion process. The phosphorus diffusion method disclosed by the invention can be used for reducing the surface concentration of the phosphorus impurities on the surface of the silicon wafer, reducing the surface minority carrier recombination rate and improving the photoelectric conversion efficiency. Compared with an existing phosphorus diffusion process, the phosphorus diffusion method disclosed by the invention has the advantages that the absolute value of the increase of the photoelectric conversion efficiency of the obtained solar battery is 0.1%, and an unexpected technical effect can be achieved.

A process of producing a composite having carbon nanotubes is described where the carbon nanotube formation process of producing carbon nanotubes includes controlled heating of plant fiber materials in an oxygen-limited atmosphere. The plant fiber materials may be heated either cyclically or by rapid heating to produce the carbon nanotubes.

A multistage oxygen-added catalytic partial oxidation process and apparatus for converting H₂S in an acid gas stream to elemental sulfur and water are disclosed. Each staged addition of oxygen or air at the top of the catalyst bed and at points along the catalyst bed maintain oxygen-limited H₂S catalytic partial oxidation conditions whereby incidental SO₂ production is minimized.

The invention discloses a treating method of soil polluted by benzene hexachloride. The treating method comprises the following steps that (1) biological sludge is subjected to drying, then oxygen-limited burning, high-temperature pyrolysis for 3-4 hours at the temperature of 300-500 DEG C, cooling, grinding, sieving through a 60-mesh sieve, washing with deionized water and drying to obtain sludge biochar powder; (2) ferrous sulfate is added into the sludge biochar powder according to the mass ratio of ferrum to mud biochar powder being 1:2-1:5, and NaBH4 is dropwise added into the mixed sludge biochar powder under the nitrogen atmosphere; and product is subjected to centrifugal washing, drying under the nitrogen atmosphere, and grinding and sieving through the 60-mesh sieve to obtain sludge biochar/nZVI composite material powder; and (3) the composite material powder is mixed with the soil polluted by the benzene hexachloride, then the water is added to prepare polluted soil slurry, and the polluted soil slurry is subjected to a stirring reaction for more than 24 hours under the closed oxygen insulation condition. The method adopts the biological sludge as a raw material, and the prepared sludge biochar/nZVI composite material powder can be used for improving the removal rate of the benzene hexachloride and promoting the resource utilization of the sludge.

The invention discloses a method for starting up a whole-course autotrophic nitrogen removal filter column, and belongs to the field of wastewater autotrophic nitrogen removal. The method comprises the steps: taking filter materials of a nitrosation biological filter column and an anaerobic ammonia oxidation biological filter column according to the mass ratio of 1:3 to 3:1, arranging the two filter materials successively, and starting up the autotrophic nitrogen removal filter column under oxygen limited continuous flow conditions. Firstly, the whole-course autotrophic nitrogen removal filter column is started up under a condition of low load, along with a fact that microorganisms in the filter column constantly adapt to the environment, the processing capability of the filter column is improved continually until ammonia nitrogen is removed basically. Then in a high-load culture stage, the load of inflow water ammonia nitrogen is improved by a way of keeping the inflow water substrate concentration constant and shortening the hydraulic power retention time, and the processing performance of the filter column is enhanced. Compared with a starting-up mode of a traditional autotrophic nitrogen removal filter column, the method has the advantages of quick starting-up, high total nitrogen removal load, less amount of anaerobic ammonia oxidation bacteria and the like.

The invention provides a recycling method of using agricultural waste to convert pig excrement and urine without external emission of pollution and particularly provides a method of raising pigs. The method comprises the steps of firstly crushing herbal agricultural waste into powdery scraps and segmented scraps and mixing the scraps to obtain a fermentation raw material; secondly, mixing the fermentation raw material and pig excrement and urine and zymophyte agents to obtain a fermentation starting material; thirdly allowing the fermentation starting material to perform aerobic fermentation under a ventilation condition and allowing the aerobic fermentation product to perform oxygen-limited fermentation under a closed condition to obtain an oxygen-limited fermentation product; fourthly using the oxygen-limited fermentation product as pigsty padding and raising pigs on the padding. With the technical solution, the method can prevent external emission of pollution of pig excrement and urine of large-scale pig raising by using herbal agricultural waste without using woody materials such as bits of wood and mushroom dregs.

The invention discloses a method for modifying biochar. The method comprises the following steps: 1) carrying out oxygen-limited pyrolysis on wheat straws and fresh whole-plant Typha orientalis into biochar, and crushing the biochar; 2) immersing the prepared biochar in hydrogen peroxide first, then immersing the biochar in an aqueous solution of maleic acid and polyethylene glycol, and cooling and filtering the obtained solution to obtain a solid phase A; 3) dispersing the solid phase A in ethanol to form a suspension, and adding 2,2,6,6-tetramethylpiperidine-nitrogen-oxide and methacrylic acid to the suspension in order to obtain a solid phase B; 4) immersing the solid phase B in an aqueous solution of acetic acid, and adding potassium periodate to the obtained solution in order to obtain a solid phase C; and 5) immersing the solid phase C in a mixed solution of dimethylformamide and N-methylpyrrolidone in order to obtain modified biochar. The modification process of the biochar is optimized, the wheat straws and the Typha orientalis are used as the composite biochar, and the composite biochar is optimized and modified, so the modified biochar has a very significant Cd repairingeffect, and significantly reduces the toxicity of heavy metals in soil after being applied to the cadmium contaminated soil.

The invention discloses a chicken feed capable of lowering blood fat and promoting production property of broiler chickens as well as a feed additive. The chicken feed is obtained by adding 1%-10% of the biomass charcoal feed additive in basic ration of chickens. The biomass charcoal feed additive is formed through carbonizing sundried wheat straws under oxygen limited and relative low-temperature conditions, crushing the carbonized wheat straws and sieving the crushed wheat straws to 60-100 meshes. The chicken feed provided by the invention can promote the production property of broiler chickens, lower abdominal fat percentage and feed conversion ratio, and especially lower the content of total cholesterol and triglyceride of broiler chickens, overcomes the defect that antibiotics and chemical synthesis additives have residues and side effects, avoids environment pollution caused by straw combustion, widens the utilization approach of biomass charcoal, and turns waste in wealth. The feed additive provided by the invention is an environment-friendly and safe feed additive which has no side and toxic effect and has no drug residue, and has wide market prospect and favorable economical and social benefits.

A disclosed preparation method for slow-release type imidacloprid granules comprises: performing oxygen-limited pyrolysis on a biomass raw material at low-medium temperature, so as to obtain a biomass adsorption material, then grinding with imidacloprid crude drug, mixing uniformly, taking sodium alginate or carboxymethyl cellulose as a binder, and utilizing a fluidized bed spray granulation technology to prepare the imidacloprid granules. Because the biomass adsorption material obtained through pyrolysis of agricultural or forestry wastes is capable of adsorbing a part of imidacloprid active composition, the release rate of the active composition can be regulated by utilizing adsorption effect. Compared with the prior art, an adsorption carrier is low in cost and easy to obtain. Also, the biomass adsorption material is relatively light in specific gravity when being used as a pesticide carrier, is convenient for fluidized bed spray granulation, and is capable of integrally realizing granulating and drying of the imidacloprid granules. Compared with the prior art, the prepared is simple and convenient to process and good in safety. The granules have slow-release effect, are beneficial for improving the utilization rate of imidacloprid and mitigating pollution of pesticides to environment.

The invention discloses a method for preparing high-adsorption ceramsite by using biochar. The method comprises: drying biomass waste, crushing, carrying out oxygen limited pyrolysis for 1-5 h at a temperature of 200-600 DEG C, cooling to a room temperature to obtain biochar, completely mixing biochar and any one or more than two selected from biogas residue powder, kaolin powder, illite, chlorite, dolomite powder, biogas residue powder, montmorillonite, bentonite powder, diatomite powder and perlite powder, stirring, granulating, roasting for 0.1-3 h at a temperature of 500-1200 DEG C, cooling, breaking, and screening to obtain the high adsorption ceramsite. According to the present invention, the high-adsorption porous biochar ceramsite with stable chemical properties can be obtained bycarrying out mixed sintering on biochar, kaolin and the like; and with the method, the pore structure of ordinary ceramsite is optimized, the ion exchange capacity is improved, the adsorption of conventional ceramsite is enhanced, and the obtained product can be efficiently used in the fields of sewage treatment, soil improvement, environmental restoration and the like.

The invention provides a method for preparing a chitosan modified biochar-based immobilized enzyme which can be used for converting high acid-value waste kitchen oil into biodiesel. Peanut shells and other biomasses are subjected to high-temperature pyrolysis to form biochar which is of a porous structure under the oxygen-limited condition, the pore structure of the biochar is further modified by adopting chitosan with high biocompatibility, chitosan macromolecules are mutually cross-linked to generate a matrix material which is of a three-dimensional meshed structure, immobilization of lipase molecules on a matrix carrier is promoted, and the catalytic activity and stability of the immobilized enzyme are improved. The catalytic activity of the immobilized lipase prepared by the method is fully improved, and the prepared immobilized enzyme can be used for a catalytic system for converting the high acid-value waste kitchen oil into biodiesel.

The invention discloses a method for stably repairing heavy metal contaminated soil by using sludge base charcoal ash. The method comprises the following steps that dewatered sludge of a sewage plantis separately taken in an oxygen-limited environment for pyrolysis and an oxygen-enriched environment for incineration to obtain low-temperature sludge base biochar and sludge incineration ash, the low-temperature sludge base biochar and sludge incineration ash are mixed with a reinforcing agent and are subjected to ball-milling to obtain sludge base charcoal ash repairing materials; the sludge base charcoal ash repairing materials are added into the heavy metal contaminated soil, water is added in the mixture for uniform stirring and mixing, and aging and maintaining are carried out to finishthe repairing. The method for stably repairing heavy metal contaminated soil by using sludge base charcoal ash has simpleness and practicality, wide source of raw materials, low price, green and energy-saving technological process, high universality, obvious and long-lasting passivation effect and no excessive requirement on equipment in construction links, is beneficial to large-scale popularization and has remarkable economic, social and environmental benefits.

The invention provides a starting method of a normal-temperature low-ammonia-nitrogen plug-flow type half-nitritation process, and belongs to the field of municipal sewage deep processing. Generally, half-nitritation is successfully started in high-temperature and high-ammonia-nitrogen SBR and can not be widely applied to engineering practice, and meanwhile the start time of a system can be prolonged due to the low dissolved oxygen concentration. Therefore, development of the method for rapidly starting nitritation under the continuous flow low-ammonia-nitrogen condition is particularly important. The running mode of two stages is adopted; in the other words, at the first stage, large-amount AOB enrichment is successfully achieved through whole-course aerobiotic and oxygen-limited running and NOB is increased as little as possible, and at the second stage, rapid starting of low-ammonia-nitrogen continuous flow half-nitritation is achieved by utilizing the combined effect of a front anaerobic pool and a follow-up oxygendepletion pool while regulating DO in the aerobiotic pool and through anaerobic, aerobiotic and oxygendepletion running.