88results about How to "Promote denitrification reaction" patented technology

The invention relates to a method for preparing a flue gas SCR (Selective Catalytic Reduction) denitration catalyst. The method comprises the following steps of: mixing ammonium metavanadate, oxalic acid, manganese salt and water for preparing a mixture solution, adding titanium dioxide powder into the mixture solution, heating in water bath and stirring, and obtaining mixed sol by standing at room temperature; putting the mixed sol into a microwave oven, heating and drying by utilizing microwave radiation; and putting dried solid into a muffle furnace for burning. According to the method disclosed by the invention, a temperature window of the SCR catalyst can be broadened to a low-temperature direction, the problems of low denitration efficiency at low temperature and narrow temperature window of a commercial catalyst are solved; compared with the traditional drying method, the microwave radiation heating and drying method has the advantages that low-temperature SCR denitration activity of the composite catalyst can be increased to a large extend, when the activity temperature is up to 250 DEG C, the denitration efficiency of the catalyst prepared by the traditional drying method is up to 51.9%, and the denitration efficiency of the catalyst can be increased by 31.7 percentage points and can be up to 83.6% by the microwave radiation heating and drying method.

The invention discloses an SCR (Selective Catalytic Reduction) denitration catalyst as well as a preparation method and the application of the catalyst, wherein, sulfated zirconia is taken as a carrier, the surface of the carrier is loaded with rare-earth metal oxides that are taken as active ingredients and is loaded with transition metal oxides that are taken as a cocatalyst. The preparation method of the catalyst comprises the steps as follows: (1), zirconia is soaked in sulfuric acid solution, and the sulfated zirconia carrier is obtained after drying and burning are carried out; and (2), the zirconia carrier is in contact with ionic or complexing metal to be loaded proportionally in any sequence, adsorption is performed, and then the SCR denitration catalyst is obtained after drying and burning are carried out. The SCR denitration catalyst achieves excellent alkali metal and alkaline earth metal poisoning resistance when being used for the flue gas denitration, and is especially suitable for the flue gas denitration when the content of alkali metal or alkaline earth metal in flue gas is higher; the denitration efficiency of the SCR denitration catalyst stabilizes at more than 95 percent under a certain condition; and the denitration efficiency can still stabilize at more than 90 percent after being soaked in alkali metal solution or alkaline earth metal solution.

The invention discloses a regeneration method for an inactivated TiV-based honeycomb denitration catalyst having the combined denitration and demercuration modification function. Firstly, the physical and chemical properties of an SCR denitration catalyst are detected, and the inactivated reasons of the catalyst are analyzed. Secondly, the regenerable catalyst is subjected to ultrasonic cleaning in deionized water, a strong alkaline solution or a strong acid solution, so that deposited ashes and pernicious elements in the catalyst can be removed. Thirdly, the cleaned catalyst is immersed in a combined denitration and demercuration regeneration solution, until the activity of the catalyst is stable. Finally, the activated catalyst is transferred to a microwave oven to be dried and calcined through the microwave heating process. The catalyst, obtained through the above method, successively has the combined oxidation and demercuration capacity, while the denitration activity of the catalyst is recovered at the same time. At a temperature smaller than 350 DEG C, the denitration efficiency of the catalyst is up to be equal to or over 90%, and the demercuration efficiency of the catalyst is up to be equal to or over 90%. Meanwhile, the condition that the cost is increased due to the demercuration process after the flue gas denitrification process can be avoided. Therefore, the method is economical and environmentally-friendly, thus being suitable for industrial promotion.

The invention relates to a sulfate radical promoted nanometer TiO2 carrier based SCR (Selective Catalytic Reduction) flue gas denitration catalyst and a preparation method thereof, belonging to the fields of environmental protection and environmental catalysis. In the invention, a SO42- / TiO2 carrier based medium / low-temperature flue gas denitration catalyst is obtained through taking sulfate radical promoted nanometer TiO2 (SO42- / TiO2) as the carrier, taking WO3 and CeO2 as auxiliaries and taking V2O5 as an active component, wherein in the composite catalysis, the mass percentage of the V2O5 is 0.5-1.5%; the mass percentage of the WO3 is 4-10%; the mass percentage of the CeO2 is 1-5%; and the balance is SO42- / TiO2. The acidity of the catalyst is obviously increased after nanometer TiO2 issubject to sulfating treatment; the denitration activity of the catalyst is increased through interacting with the V2O5, the WO3 and the CeO2; and very good catalytic activity is showed through taking ammonia as a reducing agent at a temperature of 150-450 DEG C.

The invention relates to a process for applying hydrogen to deoxygenation of liquid steel. The invention adopts the technical scheme that: when the oxygen blowing decarbonization in a converter comes to an end, or when steel ladle is refined or when the oxygen blowing decarbonization for RH ultra-low-carbon steel production comes to an end, the mixed gas of H2 or Ar-H2 is blown into liquid steel for deoxygenation, the flowrate of the mixed gas ranges from 40 to 3000m3 / h, the pressure ranges from 0.5 to 2.0 MPa, and the time of blowing the mixed gas into the liquid steel ranges from 5 to 30min. When converter or steel ladle or RH hydrogen blowing deoxygenation comes to an end, hydrogen which is dissolved in the steel is removed by argon blowing and vacuum treatment, wherein the step of blowing the gas into the liquid steel for deoxygenation is that the gas is blown into the liquid steel for deoxygenation by a gas permeable brick from the bottom of a top-bottom combined blown converter or from the bottom of the steel ladle or from an RH ascending tube; and in the mixed gas of Ar-H2, the volume content of Ar ranges from 10 to 80 percent, and the volume content of H2 ranges from 20 to 90 percent. The invention has the advantages that the process is simple, and the pollution of the liquid steel caused by deoxygenation can be reduced. The process used for removing oxygen in the steel can effectively increase the cleaness of the liquid steel and the quality of steel products.

A denitrating catalyst for the reduction reaction of Nox / NH3 gas mixture to generate N2 and H2O is proportionally prepared from bentone, TiO2, Fe2O3, CuO and H2O. Its preparing process is also disclosed. It has high thermal stability and high resistance to steam.

The invention belongs to the field of environmental protection and environmental catalysis and particularly relates to a flat-plate type high-temperature SCR (Selective Catalytic Reduction) denitration catalyst and a preparation method thereof. The preparation method comprises the following steps of: by adopting a nano composite oxide CeO2-TiO2 or CeO2-ZrO2 as a carrier, and adopting WO3 as an active component, carrying out stepped mixing, rolling coating, pleating, shearing, drying and roasting to obtain the flat-plate type high-temperature SCR denitration catalyst on the basis of adopting CeO2-TiO2 or CeO2-ZrO2 composite oxide as the carrier. The product has excellent high-temperature denitration performance, and is applicable to flue-gas denitration under the temperature of 500-700 DEG C; and the product has excellent mechanical performance, sulfur-dioxide poisoning resistance and sintering resistance.

Belonging to the technical field of low temperature SCR denitration, the invention discloses an active carbon loaded iron-based low temperature SCR denitration catalyst, a preparation method and application method thereof. The preparation method includes: taking grinded activated carbon as the carrier, using an Fe oxide as the main active component, adding trace Mn or Co as the active assistant respectively, loading the active component on the carrier by impregnation method, then conducting magnetic stirring and drying treatment, and finally performing roasting in air atmosphere, thus obtaining the low temperature SCR denitration catalyst. The low temperature SCR denitration catalyst provided by the invention has the characteristics of convenient production, simple use, and good denitration effect at low temperature, can well solve the problems of low denitration efficiency and slightly high use temperature section in existing denitration catalysts, thus being conducive to prolonging the service life of the catalyst, and saving cost.

The invention belongs to the field of environment friendliness and environment catalysis, in particular relates to an SCR (Selective Catalyctic Reduction) smoke denitration catalyst based on a TiO2-SnO2 composite barrier. The medium-low temperature smoke denitration catalyst based on the TiO2-SnO2 composite barrier is prepared by using nanometer TiO2-SnO2 as a carrier, WO3 and CeO2 as additives and V2O5 as an active component. By adopting the nanometer TiO2-SnO2 for replacing the traditional nanometer TiO2 as the carrier, the specific surface area, the thermal stability and the acidity of the catalyst are increased, the denitration activity of the catalyst is improved through interaction among the V2O5, the WO3 and the CeO2; and when ammonia is used as a reducing agent, better catalytic activity is expressed within a temperature range of 150-450 DEG C.

The invention relates to a ceramic catalytic filter element for flue gas purification and a flue gas desulfurization and denitrification integrated dust removal method. The ceramic catalytic filter element is prepared from the following steps that a microporous alumina ceramic filter tube with a pore diameter of 40-80 microns is taken as a matrix; the matrix is immersed in a mixed sol made of zincacetate, and after the matrix is impregnated under a negative pressure, the matrix is roasted to obtain a modified matrix modified by zinc oxide; an equal volume impregnation method is adopted, and the modified matrix is impregnated with an mixed oxalic acid solution containing ammonium metavanadate and ammonium metatungstate, so that total loading mass of V2O5 and WO3 in pores of the matrix reaches 4.0%-6.0% to obtain an active matrix; the active matrix is immersed in a mixed sol made of Al2O3-SiO2-TiO2, the active matrix is dried and roasted after the active matrix is taken out, and a densefilm with a thickness of 0.2-0.6 millimeter and a pore diameter of 1-10 microns is formed on the outer surface of the active matrix to obtain the ceramic catalytic filter element. A denitrification catalyst of the ceramic catalytic filter element has the advantages of being strong in load, high in denitrification efficiency, long in service life and applicable to popularizing and using.

The invention specifically relates to a flat-plate type sulfur-resistant low-temperature SCR denitration catalyst and a preparation method thereof, belonging to the fields of environmental protection and environmental catalysis. The method comprises the following steps: with nanometer composite oxide Ce-ZrO2 as a carrier, manganese oxide as an active component and iron oxide and molybdenum oxide as cocatalysts, carrying out equivalent-volume impregnation, drying, roasting and crushing so as to prepare a powdery catalyst; and subjecting the prepared powdery catalyst to acidification by sulfuric acid and then carrying out mixing, rolling coating, fold pressing, shearing, drying and roasting so as to obtain the flat-plate type sulfur-resistant low-temperature SCR denitration catalyst. The prepared catalyst has denitration activity of 85 to 98% in a temperature range of 80 to 150 DEG C and has excellent resistance to sulfur dioxide poisoning.

The invention discloses an SCR (silicon controlled rectifier) denitration system of cement kiln gas. The SCR denitration system comprise an ammonia spraying device, a reactor box body, a wind evening rectifying device, catalysts and sound wave soot blowers, wherein the wind evening rectifying device and the catalysts are respectively arranged on the upper part and the lower part in the reactor box body; and the sound wave soot blowers are arranged in the reactor box body. The SCR denitration system also comprises an electrofilter and a mixing device, wherein the electrofilter comprises a gas inlet and a gas outlet; and the gas inlet of the electrofilter is provided with a gas inlet pipeline. The ammonia spraying device and the mixing device are respectively arranged on the gas inlet pipeline, the mixing device is positioned on the down stream of the ammonia spraying device, an exit of the electrofilter is connected with the upper end of the reactor box body by a gas collection cover, the lower end of the reactor box body is provided with a lower cone bucket, and the lower cone bucket is connected with a gas outlet channel. The SCR denitration system of the cement kiln gas is long in service life and low in use cost.

The invention discloses a method and a device for reducing endogenous nitrogen in an eutrophic water body by utilizing submerged plants to couple sediment a sediment microbial fuel cell. The method comprises the following steps: A, planting the submerged plants in sediment of the eutrophic water body; B, embedding a positive plate under a bottom mud layer-water interface and near root systems of the submerged plants; C, setting a negative plate on a water-air interface, enabling a positive material to suspend in water and the negative plate to be partially exposed in the air; D, connecting thepositive plate with the negative plate by using a guide lines and an external resistor, thus forming a current loop. The submerged plants are rooted in bottom mud, holes in the middle part of the positive plate penetrate through the submerged plants and are located at the lower part of a mud-water interface, an upper water covering layer is located on the mud-water interface, the negative plate is suspended on an upper water covering layer-air interface, one end of an external guide wire is connected with the positive plate, and the other end is respectively connected with the external resistor and the negative plate. The method disclosed by the invention is simple, the operation is convenient, and the structure is simple; the endogenous nitrogen is changed into gaseous nitrogen through adenitrificaiton process and is removed out of the water body, and the concentration of nitrogen nutrient in the bottom mud is remarkably reduced.

The invention relates to a treatment method for sewage. Wherein, keeping the sewage flowing from lower to upper during the whole process; first, taking denitrifying treatment in hypoxia segment to remove total nitrogen and phosphorus; then, treating in aerobic segment to reduce the COD, BOD5 and SS as well as the ammonia nitrogen by nitration. Besides, the opposite equipment is a vertical-arranged bioaeration filter tank with an aeration pipe on proper position.

The invention discloses a polymer solid powder denitration agent for flue gas denitration and a preparation method thereof. The polymer solid powder denitration agent comprises the following raw materials in percentage by weight: 10-70% of an organic amino active compound, 10-40% of an inorganic active amino compound, 5-40% of inorganic mineral substance powder, 5-30% of active mineral substance powder and 1-10% of an additive. The polymer solid powder denitration agent has the advantages of simple components, easily available raw materials, simple preparation method, high denitration efficiency, high cost performance and good fluidity, is convenient for conveying the denitration agent in a denitration process, can improve the denitration efficiency of the denitration agent and reduce secondary pollution, and overcomes the defects in the prior art.

The invention relates to an absorption tower for denitrating flue gas by using bleaching effluent and a denitrating method thereof. The absorption tower comprises a tower body, wherein the top of the tower is provided with a flue gas outlet, the bottom is provided with an overflow vent, and the tower body is sequentially provided with a flue gas inlet, a slurry spraying area and a demister area from bottom to top. In the method for denitrating the flue gas by using the bleaching effluent, NOx in the flue gas is removed by using the bleaching effluent, therefore, the flue gas can be discharged after reaching standards, acidic materials which are added when the bleaching effluent is discharged can be saved, and the chemical oxygen demand (COD) of the bleaching effluent after denitration can be greatly reduced, which is beneficial to further treating the bleaching effluent at a sewage treatment station. By adopting the method, waste water and exhaust gas are comprehensively treated, and the cost for treating the waste water and the exhaust gas is greatly reduced.

The invention relates to a strengthened ammonia injection denitration method based on surface catalytic performance of iron ore pellets. The method comprises the following steps of preparing green pellets by ingredients, drying and preheating a chain grate machine, and configuring ammonia injection denitration operation at an air draft drying section of the chain grate machine. The method is characterized by 1) determining pellet raw materials and a basic binder; 2) preparing a composite binder; 3) preparing green pellets with strong catalytic surfaces containing the composite binder; and 4) strengthening ammonia injection denitration on a pellet surface layer, decomposing and volatilizing the composite binder in a drying process to form rich pores in the pellet surface layer, increasing adsorption of NH3 and NOx on the pellet surface layer, accelerating a denitration reaction speed of the strong catalytic surface layer, and realizing strengthened ammonia injection denitration of thepellet surface layer. The method has advantages that a denitration rate is improved by more than 15 percent points compared with that of an existing ammonia spraying denitration technology; a pelletizing process does not need to be greatly changed, and only some improvements need to be made in the process of preparing the green pellets from the ingredients; and implementation and popularization are easy.

The invention discloses a bioretention system suitable for processing urban initial rainwater in a severe nitrogen pollution area. The system is composed of a water inlet facility, an overflow facility, plants, a filler layer, an internal water level regulating and controlling facility and a water discharging facility; the water inlet facility intercepts runoff with extremely poor water quality inthe initial stage of rainfall through a surface-layer water inlet pipe; the overflow facility includes an overflow weir and an overflow pipe; the plants are planted at the surface of the filler layer, and a planting mode of the plants is optimized according to the nitrogen removing characteristics of the plants; the filler layer realizes high-efficiency nitrogen removal through addition of a novel nitrogen-removing material; the water discharging facility promotes infiltration, interception and discharge of rainfall runoff in the system by utilizing perforated water-discharging pipes arrangedat the bottom of the system; and the internal water level regulating and controlling facility is a U-shaped pipe, an internal water storage layer is formed in the water inlet process through a theoryof communicating vessels of the U-shaped pipe, a height of the U-shaped pipe can be adjusted to create the aerobic-anaerobic alternating environment required for the nitrogen removal, and the top ofthe U-shaped pipe is provided with a sensor to control water inflow to ensure effective storage and retention of the initial rainwater.

The invention provides a denitrification system and a denitrification method for a gas turbine. The denitrification system comprises the gas turbine and a reducing agent supplying system. A denitrification reducing agent is provided for a turbine by using a reducing agent output pipeline communicated to the rear part of a first-stage moving blade of the turbine of the gas turbine; nitric oxide influe gas, exhausted from a combustion chamber of the gas turbine, is contact with the denitrification reducing agent in the turbine of the gas turbine to carry out selective non-catalytic reduction reaction, and denitrification of the flue gas is finished, wherein before the reducing agent enters the turbine for reacting, more free radicals can be generated by plasma treatment and facilitate a denitrification reaction. By using the technical scheme provided by the invention, denitrification is realized in the turbine of the gas turbine, and high pressure and high rotating speed of the turbineof the gas turbine are sufficiently utilized, so that the mixing of the reducing agent and the flue gas is benefited, the denitrification reaction is promoted, and the denitrification efficiency is improved; besides, post treatment equipment also can be reduced, so that the complexity of the system and investment expenses of equipment are reduced.

The invention discloses a denitrification water treatment agent. The agent is a mixture of an inorganic substance, a biosynthesis high-molecular polymer and a natural degradable organic matter, wherein the contents of the inorganic substance, the biosynthesis high-molecular polymer and the natural degradable organic matter are, on the basis of weight, 5 to 30%, 50 to 90% and 5 to 30%, respectively. The denitrification water treatment agent provided by the invention can remove nitrite and nitrate in water at a temperature of 5 to 35 DEG C, has a wide adaptive temperature range in the process of a denitrification reaction and even can well realize a denitrification reaction at a temperature of 5 to 10 DEG C.

The invention provides a marine low-speed diesel exhaust gas collecting tank with a catalytic denitration function. The gas collecting tank comprises a gas collecting box and a catalytic denitration module arranged in the gas collecting box, the exhaust gas inlet of the gas collecting box is connected with the exhaust manifold of every cylinder of a diesel engine, the exhaust gas outlet of the gascollecting box is connected with a turbine, and the catalytic denitration module comprises a urea injector head, a static mixer and a double-layer catalyst module; and exhaust gas is mixed with a urea solution, and the obtained solution goes through the static mixer and the double-layer catalyst module. The gas collecting tank adopting the above configuration has the advantages of simple structure, easiness in arrangement, and improvement of the system compactness of the gas collecting tank; a baffle plate is mounted behind an exhaust gas flow to effectively prevent a reaction gas from flowing back into the cylinders, the high temperature of the exhaust gas is used to preheat the catalytic denitration module in order to improve the residual heat utilization rate of the exhaust gas, and the exhaust gas enters an upper chamber from a lower chamber in a baffling manner under high-temperature and high-pressure conditions in order to reduce the linear velocity, so efficient removal of NOxin the exhaust gas is achieved.

The invention discloses a long-term low intensity aeration reoxygenation polluted river and lake water body treatment method and device thereof, relating to the environment protection technical field, in particular to the oxygenation aeration river and lake water pollution treatment technology. The method includes controlling an aeration device arranged in water body according to dissolved oxygen concentration in river or lake water body and concretely includes measuring dissolved oxygen DO in river or lake water, opening the aeration device to operate when the dissolved oxygen DO is less than 0.8mg / L and closing the aeration device when the dissolved oxygen DO is more than 1.5mg / L. The device is a dissolved oxygen automatic controller the monitoring end of which is arranged in the river or lake water, the control terminal is connected with the power control terminal of the aeration device, and the aeration device is arranged in river or lake water. Through implementation, the invention has the beneficial effect that removing effect of water body on pollutant is remained while the aims of reducing energy consumption and saving water body treatment operation cost are achieved by controlling relatively low dissolved oxygen concentration in water body. The invention has more popularized value in rural and remote areas where energy source is relatively tight.

The invention provides equipment and method for removing nitrogen out of domestic wastewater. An outer tank body is arranged on the equipment, wherein a first anaerobic tank, a second anaerobic tank, an aeration tank, a precipitation tank and a sterilization tank are sequentially arranged inside the outer tank body; an inflow pipe extending into the first anaerobic tank is arranged on a lateral wall surface of the outer tank body; contact filter materials are arranged inside the first anaerobic tank and the second anaerobic tank; a first duct extending into the second anaerobic tank is arranged inside the first anaerobic tank; a second duct extending into the aeration tank is arranged inside the second anaerobic tank; an aeration system and a reflux pump are arranged at the bottom of the aeration tank; a reflux pipe extending into the first anaerobic tank is arranged on the reflux pump; a biomass carrier is placed into the aeration tank; a communicated channel is arranged at the bottom of the wall surface between the aeration tank and the precipitation tank; a third duct extending to the sterilization tank is arranged inside the precipitation tank; a disinfectant is injected into the sterilization tank; and a release pipe is arranged on the wall surface of sterilization tank on the outer tank body.

The invention relates to a preparation method for improving low temperature activity of carbon-based SCR catalyst, which belongs to the technical field of denitration catalyst preparation. According to the invention, V2O5 is used as an active component, activated carbon is used as a carrier, the activated carbon is weighed and subjected to oxidation treatment with nitric acid, and the material issubjected to filtration, washing and drying; the oxalic acid is weighed and dissolved in deionized water, after the solution is dissolved, a vanadium precursor is added, after the solution turns blue,the nitric acid-treated activated carbon is added; an obtained mixture is stirred and impregnated at different powers in a microwave oven chamber, and then is subjected to calcination under differentatmospheres to obtain a V2O5 / AC catalyst. The invention has simple process, strong operability, mild reaction conditions and short required time. The active component on the catalyst carrier is regulated by microwave processing power and immersion time. The V2O5 species on the V2O5 / AC catalyst after microwave treatment is more evenly dispersed, particle aggregation is reduced, more active sites can be provided, and the denitration performance of the catalyst s increased.

The invention discloses a denitration catalyst, which is composed of the following components: 30-70 parts by weight of bentonite, 5-20 parts by weight of TiO2, 5-10 parts by weight of Fe2O3, and 5-15 parts by weight of CuO , 3-6 parts by weight of water. The invention also discloses a preparation method of the above-mentioned denitration catalyst. The invention composes multiple oxides based on the nano-layer structure of natural bentonite, makes the catalyst porous and achieves low-cost large-scale industrial application. When the mixture of NOx / NH3 enters the well-developed pore structure on the surface of the catalyst and undergoes a reduction reaction with the catalyst to generate N2 and H2O, the product gas can escape easily, which is very beneficial to the denitrification reaction. The preparation process of the invention is simple and controllable, and the cost is very low. The invention not only improves the thermal stability and water vapor resistance performance of the denitrification catalyst, but also is environmentally friendly.

The invention discloses a catalytic reduction type de-nitrification reactor of a circulating fluidized bed. The catalytic reduction type de-nitrification reactor comprises a reactor housing with a reactor inner cavity, wherein the bottom and the top of the reactor housing are respectively provided with an inlet flue and an outlet flue; the lower part of the reactor inner cavity is provided with an air distribution plate with air distribution holes; a filtering container is arranged above the air distribution plate in the reactor inner cavity and is used for intercepting a catalyst; the periphery and the top of the filtering container are sealed; the lower part of the filtering container is provided with a downward opening; the container wall of the filtering container is provided with filtering holes; a material returning channel in which the catalyst drops is remained between the external surface of the container wall of the filtering container and the inner wall of the reactor inner cavity; material returning openings connected with the material returning channel are formed between an opening edge of an opening of the filtering container and the air distribution plate or formed in the container wall of the lower part of the filtering container. Through the de-nitrification reactor disclosed by the invention, the amount of the catalyst removed from the fluidized bed along with flue gas is greatly reduced, the catalyst can react in the de-nitrification reactor all the time, and the utilization rate of the catalyst is effectively increased.

The invention relates to a coking wastewater optimizing treatment process and device. The process is as follows: light oil and heavy oil contained in the coking wastewater are firstly removed in an oil separator; then air flotation treatment is carried out to reduce ammonia nitrogen; water distribution is carried out in a regulating tank; after water distribution, 70% of the coking wastewater is introduced into an aerobic tank 1, and 30% of the coking wastewater is introduced into an anaerobic tank; after the coking wastewater is subjected to treatments in the aerobic tank 1, a sedimentation tank I, the anaerobic tank, an aerobic tank 2, a sedimentation tank II, a coagulative precipitation tank and a deep treatment tank in sequence, the quality of the final effluent is as follows: COD is lower than 80 mg / L, ammonia nitrogen is lower than 10 mg / L, volatile phenol is lower than 0.3 mg / L, cyanogen is lower than 0.2 mg / L, oil and suspended solids are basically removed, and water quality indicators meet the discharge standards. According to the invention, the process route is short, the equipment investment cost is low, the processing efficiency is high, the effect is stable, energy conservation and cost reduction are achieved, and economic and social benefits are remarkable.

The invention discloses a Mn-Fe-Al-Si low-temperature SCR catalyst, a preparation method and applications thereof, and belongs to the technical field of low-temperature SCR denitration. According to the SCR denitration catalyst, SiO2 solid powder, a Fe(NO3)3 solution, a Mn(NO3)2 solution and a Al(NO3)3 solution are adopted as main raw materials, active components are supported on the carrier SiO2 by using an impregnation method, magnetic stirring and drying treatment are performed, and finally calcination is performed in an air atmosphere so as to obtain the SCR denitration catalyst, wherein the SCR denitration catalyst uses SiO2 as the carrier and uses MnOx, FeOx and Al2O3 as the active components, and a mass ratio of Mn to Fe to Al to Si in the catalyst is (1.4-1.6):(1.1-1.3):(0.2-0.4):1. According to the present invention, with the technical scheme, the denitration effect of the catalyst at the low temperature can be significantly improved, the service life of the catalyst is easily prolonged, the denitration efficiency stability at the low temperature is good, and the denitration catalyst is suitable for the promotion application in power plant flue gas denitration or coking plant denitration and other low temperature SCR denitration.

The invention belongs to the technical field of catalysts, and particularly relates to a preparation method of an oxidation catalyst used for a diesel vehicle. The method comprises the following stepsof (1) preparing mixed-phase catalyst slurry A; (2) preparing precious metal-containing slurry B; (3) preparing precious metal-containing slurry C; (4) preparing molecular sieve-containing slurry D;(5) preparing bottom layer coating slurry and surface layer coating slurry; (6) coating a carrier with the bottom layer coating slurry and the surface layer coating slurry in sequence. Compared with the prior art, the preparation method of the oxidation catalyst used for the diesel vehicle adopts a novel coating technology and a small amount of precious metals, and a prepared oxidation catalyst coating is even in distribution, good in thermal stability and low in initiation temperature, and has very good capability of oxidizing NO in diesel vehicle tail gas and SOF in particles.

The invention relates to a method for treating excess activated sludge by using ultrasonic wave and Fenton reaction, particularly to treatment of excess activated sludge by combining ultrasonic pretreatment of excess activated sludge, Fenton oxidation and denitrification denitrogenation digestion. According to the present invention, the excess activated sludge is effectively dispersed and crackedthrough ultrasonic waves to reduce the particle size of the excess activated sludge, such that the specific surface area of the excess activated sludge is increased so as to improves the reaction efficiency during the Fenton oxidation of the excess activated sludge; the free radical strong oxidation group generated through the Fenton oxidation reacts fully with the cracked excess activated sludge,such that the excess activated sludge is digested, and the lysis of the excess activated sludge can be promoted; the excess activated sludge after the Fenton oxidation returns to the denitrificationpool, and can be used as the feeding carbon source during the denitrification so as to reduce the denitrification; and the method has characteristics of stable treatment effect, high reaction efficiency, full utilization of resources, easy industrialization, and the like.