1641results about How to "Improve denitrification effect" patented technology

The invention relates to a method for preparing a catalyst for flue gas denitrification. The method comprises the following steps: step 1: preparing a powder mixture of titanium dioxide nanoparticles, binders and auxiliaries; step 2: preparing an oxalic acid solution of tungsten and vanadium; step 3: mixing the powder mixture produced in the step 1 and the solution produced in the step 2 to obtain a catalyst slurry; and step 4: uniformly spreading the catalyst slurry produced in the step 3 on a surface-treated stainless steel net, rolling and molding, drying and calcining to obtain the final catalyst. Furthermore, the invention also relates to a catalyst for flue gas denitrification, which is prepared by the method. The catalyst with high mechanical strength and excellent catalytic activity overcomes the problem that the prior catalyst for flue gas denitrification has poor mechanical strength after molding.

The invention pertains to a field of the technique development of sewage treatment system. The invention is designed to solve the problem of instability and low standard-reaching rate of biological denitrification and phosphorus removal technic A2/O. The problem is caused by the competition of carbon source. The invention is based on the theory of dephosphorization and denitrification by denitrification and reasonably takes the advantage of the idea that intake carbon sources can be used instead of additional carbon sources to improve denitrification rate. The invention is designed to update the technic A2/O to the technic (A2/O+A/O) of anaerobia-anoxia 1-aerobic 2-anoxia 2-aerobic 2, and the invention can also optimize the nutrient removal ability of the technic (A2/O+A/O) by starting the switches of aeration and stirring and side-flow pump in anoxia 2 zone according to different quality and quantity of intake water. The invention can also fully exert the denitrification phosphorus removal performance and effectively use the intake carbon source within the technic (A2/O+A/O), can effectively improve water quality, evidently reduces operation cost and reforms operation status. The invention is applicable to urban sewage treatment which demands on a nutritive matter emission standard.

The invention relates to a rare-earth-based SCR denitration catalyst and a preparation method thereof, and belongs to the technical field of environmental catalysis. The catalyst is a denitration catalyst which is compounded from CeO2 and TiO2 at the medium and low temperature, the active component of the catalyst is cerium dioxide, the carrier is titanium dioxide, and the assistant is transition metal and rare earth metal oxide; and the structural formula of the catalyst is CeO2-MOx/TiO2, CeO2/Mox-TiO2 or CeMTiOy, wherein M is one or several kinds of compounds selected from Al, Si, Y, Zr, Nb, Mo, Sn, Sb, La, Pr, Nd, Sm and W, x ranges from 1 to 3 and y ranges from 2 to 5. The invention has the advantages that no toxic substance V2O5 is used in the catalyst, the catalyst has good NO(i) x(/i) conversion rate, N2 selectivity and NH3 conversion rate in the range of 200-500 DEG C, the SO2 conversion rate is small, the H2O and alkali metal poisoning prevention capability is superior to that of commercial vanadium-titanium catalysts.

The invention provides a chemical fertilizer waste water treatment process control method. The process comprises the following steps of: homogenizing chemical fertilizer waste water through a regulating pool; then pumping the waste water in the regulating pool into a primary aeration tank by utilizing a sewage pump so as to primarily remove COD (chemical oxygen demand) and relieve toxic and side effects for a subsequent biological and chemical system; after the waste water is treated by a primary sedimentation tank, ensuring that the waste water enters an A/O (anacrobic/oxic) biological denitrification system and a subsequent materialization deep treatment system; keeping DO (dissolved oxygen) of a pool A (anoxia pool) being below 0.5mg/L and the water flow of nitration liquid refluxing from a pool O (oxic pool) being 3-5 times of that of inlet water; maintaining the pH of the pool O to be 6.5-8.5 and the DO to be 2-3mg/L; and regulating to a proper mud reflux ratio so as to ensure that the biological and chemical system can be efficiently and stably operated. The materialization deep treatment system is used for adding flocculating agents PAC (polyaluminium chloride) and PAM (polyacrylamide), and after reaction and precipitation, outlet water can reach the national first-level discharge standard.

The invention belongs to the technical field of denitration catalysts and particularly relates to a SiO2-containing denitration catalyst and a preparation method thereof. The denitration catalyst comprises the following components in percentage by mass: 1 to 2 percent of V2O5, 5 percent of WO3, 5 to 10 percent of SiO2 and the balance of TiO2. The preparation method of the denitration catalyst comprises the following steps of: preparing a TiO2-SiO2composite carrier by a co-precipitation method; loading V2O5 and WO3 by a one-step impregnation method; and obtaining the catalyst with high low-temperature denitration by roasting. The method has the characteristics of increasing the overall mechanical strength, wear resistance, and other performance of the catalyst; the silica solution used as a cheap silicon source for SiO2 can be well improved in mechanical performance in processing, extruding and forming processes.

The invention discloses a preparation method of a catalyst for hydrogenation desulfurization and denitrification of light-weight oil and is characterized in that the composition of the catalyst comprises a carrier, an auxiliary agent and active metals, wherein the carrier contains aluminum oxide, titanium oxide and silicon oxide; the auxiliary agent is phosphorus; the active metals are oxides of nickel, molybdenum and tungsten; and on the basis of the catalyst, the contents of all components in percentage by weight are as follows: 1 to 4 percent of cobalt oxide, 3 to 10 percent of nickel oxide, 2 to 12 percent of molybdenum oxide, 18 to 30 percent of tungsten oxide, 2 to 5 percent of phosphorus pentoxide, 2 to 15 percent of titanium oxide, 2 to 20 percent of silicon oxide, and the balance of aluminum oxide. The catalyst is obtained by the steps of carrier preparation, co-immersion, calcination and the like.

The invention provides desulfurated and denitrated activated coke and a preparation method thereof. The desulfurated and denitrated activated coke is prepared from lignite and coking coal which are crushed into certain fineness, pitch, tar, vanadium pentoxide, copper oxide and water through kneading, shaping, drying, charring and activating. The desulfurated and denitrated activated coke prepared from the raw materials by the method not only has good desulfuration and denitration effect but also has low cost, simplicity in preparation and strong practicability.

The invention discloses a macromolecular dry denitrifying agent. The agent is prepared from components of raw materials in parts by weight as follows: 40-50 parts of urea, 10-20 parts of melamine and/or cyanuric acid, 20-30 parts of organic activated carbon powder, 10-15 parts of magnesium oxide, 10-15 parts of sodium carbonate, 20-25 parts of bentonite, 10-20 parts of quicklime and 1.0-1.2 partsof a catalyst. Meanwhile, the invention also provides a preparation method of the macromolecular dry denitrifying agent as well as a denitrifying technology and denitrifying equipment using the macromolecular dry denitrifying agent. The denitrifying agent obtained with the technical scheme is simple to prepare and low in cost. The dry denitrifying technology and denitrifying equipment using the denitrifying agent can treat flue gas with wider temperature ranges, have high denitrifying efficiency, have no ammonia escape and other side effects and have good application prospects.

The invention discloses a monolithic cellular catalyst for SCR smoke denitration, which adopts TiO2 powder as a substrate. The catalyst is added with active ingredients and additive at the same time. The active ingredients comprise TiO2, WO3, MoO3, V2O5, ZrO2 and MnO2. The additive comprises water reducer, binder, pore-forming agent, extrusion assistant and glass fiber. The invention further discloses a preparation technology for the monolithic cellular catalyst for SCR smoke denitration, comprising the following steps: dry mixing, kneading and pugging to obtain a mud section with good plasticity and a compact structure; extruding to obtain the blank of the monolithic cellular catalyst; drying and baking to obtain the monolithic cellular catalyst for SCR smoke denitration. The invention has simple preparation technology, greatly reduces the water quantity during the kneading process through adding the water reducer which is adopted as one active ingredient, reduces the maintaining conditions of the catalyst after being formed, and improves the strength, abrasion resistance and yield for forming the catalyst.

The invention provides a device and a method for treatment of low-temperature and low-carbon ammonia nitrogen wastewater on the basis of solid-phase denitrification and heterotrophic nitrification-aerobic denitrification. The device comprises a reactor and a reflux system, wherein the upper part and lower part of the reactor are respectively provided with a fluidized bed aerobic zone and a filterpool anoxic zone which are filled with a solid carbon source filling material and separated by a porous water distribution plate; an aeration tube is arranged on the water distribution plate and connected with an aeration device through a gas flowmeter; the lower end of the reactor is provided with a water inlet; the upper end of the reactor is provided with a water outlet; an effluent of the reactor enters a secondary sedimentation tank, and an effluent of the secondary sedimentation tank enters an intermediate water storage tank through an overflowing opening; the upstream end of the refluxsystem communicates with an effluent of the intermediate water storage tank; the downstream end of the reflux system communicates with the reflux opening of the lower end of the reactor through a liquid flowmeter; and the interior of the fluidized bed aerobic zone is provided with a dissolved oxygen monitor and a nitrate concentration monitor. The device and the method provided by the invention can still realize highly-efficient removal of ammonia nitrogen and total nitrogen under the conditions of low temperature and low carbon.

The invention discloses a denitrification method of wastewater generated in the process of producing catalytic cracking catalysts. The method comprises the step of adding nitrobacteria and a denitrification agent to sewage, wherein the denitrification agent contains arthrobactercreatinolyticus FDN-1, flavobacteriummizutaii FDN-2, paracoccusdenitrificans DN-3 and methylobacteriumphyllosphaerae SDN-3. The method adopts autotrophic bacteria and heterotrophic bacteria which are subjected to combination of superiority to serve as reinforced microorganisms for wastewater treatment, adopts different addition modes, can achieve removal of ammonia nitrogen, total nitrogen and CODcr in the same reactor, has a good wastewater treatment effect, truly achieves short-cut nitrification and denitrification or simultaneous nitrification and denitrification of ammonia-containing catalyst wastewater by being combined with high-efficiency devices, and achieves up-to-standard discharge of pollutants such as ammonia nitrogen and the like in the wastewater.

The invention discloses an integral multistage internal recycle nitrating-denitrifying biological denitrifying fluid-bed reactor, which comprises the following parts for the open structured case space from downward to upward: fluid reacting zone with anoxic zone, high-density aerobic zone, low-density aerobic zone, three-phased separating zone, wherein the adjacent zones interconnect mutually; the anoxic zone, high-density aerobic zone, low-density aerobic zone of fluid reacting zone is formed by zone baffle on the cylinder body of the reacting zone; each circulating baffle is set each fluid reacting zone to make the interval flow form interval circulation filled with porous polymer macromolecular carrier when operating; three-phased separating zone is composed of separating zone cylinder, upper and lower separating cylinders in the cylinder and water outlet weir between the cylinder and separating cylinder, which discharges the purified water through water outlet weir and the degas into the atmosphere through open.

The invention discloses a compound vertical flow artificial wetland oxygen increasing system. The system consists of an air compressor, a compound vertical flow artificial wetland, a downlink flow pool and an uplink flow pool; the downlink flow pool which is communicated with the bottom and the uplink flow pool form a compound vertical flow artificial wetland, the bottom of which is provided with at least three emptying tubes which are connected in parallel; the walls of the emptying tubes are provided with through holes; the emptying tubes at the bottom of the downlink flow pool are internally and respectively provided with perforated aeration tubes which are connected in parallel; and one end of the perforated aeration tube is closed, and the other end thereof is connected with an airway which is connected with the air compressor of the ground surface. The invention has simple structure and is provided with emptying tubes at the bottom of the compound vertical flow artificial wetland, conducts intermittent aeration in the emptying tubes at the bottom of the downlink flow tool on the optimized oxygen increasing condition, creates an environment condition of aerobic and anaerobic alternate change which is required by the nitrification and denitrification reactions, and greatly enhances the denitrification effect.

The invention discloses a device and a method for realizing sludge digestive fluid advanced nitrogen removal by a three-section type short-cut nitrification- anaerobic ammonia oxidation-short-cut denitrification process. Sludge digestive fluid firstly enters a short-cut nitrification reactor, residual nitrite from the last cycle is removed by sufficiently utilizing organic substances in the digestive fluid through anoxic stirring and then aeration is performed to carry out partial nitrification; effluent containing nitrite is mixed with another part of the sludge digestive fluid to obtain a mixture, the mixture enters an anaerobic ammonia oxidation reactor for denitrification, and effluent enters the short-cut denitrification reactor, so that nitrate generated in an anaerobic ammonia oxidation reaction process is converted into nitrite, and the nitrite flows back into the anaerobic ammonia oxidation reactor so as to be further removed together with ammonia nitrogen in raw material. According to the device and the method, excessive nitrate in the effluent of the anaerobic ammonia oxidation reactor is reduced into a substrate nitrite needed for anaerobic ammonia oxidation reaction; and moreover, carbon source consumption is low, sludge yield is low, and a three-section type reactor can beflexibly controlled, and is suitable for advanced nitrogen removal of wastewater with high ammonia nitrogen and a low carbon-nitrogen ratio.

The invention relates to a four-component NH3-SCR supported metal catalyst for low-temperature flue gas denitrification and a preparation method of the four-component NH3-SCR supported metal catalyst. The invention provides the NH3-SCR catalyst which is obtained by supporting nitrates of Mn, Co, Ce and other elements on nano-scale TiO2-P25 by using a dipping method and roasting to form a multi-component composite metal oxide. The catalyst has acidity and oxidization and is conductive to activating NH3 on the surface of the catalyst by adsorption and improving the denitrification efficiency. The invention further provides the preparation method of the catalyst.

The invention relates to a high-ammonia-nitrogen low-C/N-ratio wastewater treatment system and treatment technique, belonging to the technical field of wastewater treatment. The system comprises a hydrolysis acidification tank, an anoxic tank, a microaerobic nitrosification tank and an aerobic tank, wherein the hydrolysis acidification tank communicates with the anoxic tank; the anoxic tank is connected with the microaerobic nitrosification tank through a pipeline; the microaerobic nitrosification tank is connected with the aerobic tank through a pipeline; a nitrosification liquid reflux pipeline is arranged between the microaerobic nitrosification tank and the anoxic tank; and a nitrosification solution reflux pipeline is arranged between the aerobic tank and the anoxic tank. The treatment system and treatment technique have favorable enhancement effects on wastewater treatment and reconstruction of leather wastewater, synthetic ammonia and nitrogen fertilizer techniques, and are suitable for treating high-ammonia-nitrogen low-C/N-ratio wastewater. The treatment system and treatment technique have the advantages of favorable denitrification effect and low operating cost, and can achieve the goal of simultaneously removing ammonia nitrogen and total nitrogen.