Disclosure of Invention
Aiming at the defects in the prior art, the invention provides the method for treating the wastewater by ozone catalytic wet oxidation, which has high COD removal capacity, can improve the effective utilization rate of ozone, reduce the ozone addition amount and greatly improve the economy of the whole treatment process.
The invention provides a method for treating wastewater by ozone catalytic wet oxidation, which comprises the following steps: the method comprises the following steps that organic wastewater and ozone enter a reactor to react, and a catalyst A and a catalyst B are sequentially filled in the reactor according to the contact sequence of the organic wastewater, wherein the catalyst A is a supported catalyst, the active component of the supported catalyst is transition metal or noble metal, and the carrier is one or more of activated carbon, a molecular sieve and an oxide; the catalyst B comprises a composite carrier and an active metal component, wherein one or more of transition metals Fe, Cu, Mn, Ti and Zn are used as the active metal component, the composite carrier comprises active carbon and basic carbonate, and the basic carbonate is distributed on the outer surface of the active carbon, wherein the active carbon accounts for 35-90% of the total weight of the composite carrier, and preferably 40-80%; the basic carbonate accounts for 10-65% of the total weight of the composite carrier, and preferably 20-60%; the basic carbonate is basic magnesium carbonate or a mixture of the basic calcium carbonate and the basic magnesium carbonate.
In the method for treating wastewater by ozone catalytic wet oxidation, the volume ratio of the catalyst A to the catalyst B is 20-80%: 20% to 80%, preferably 30% to 60%: 40 to 70 percent.
In the method for treating wastewater by ozone catalytic wet oxidation, transition metal in the catalyst A is one or more of iron, cobalt, nickel, copper, zinc and manganese, preferably one or more of iron, copper and manganese, and the noble metal is one or more of platinum, palladium, ruthenium, rhodium and iridium, preferably platinum and/or ruthenium.
In the method for treating wastewater by ozone catalytic wet oxidation, the oxide in the catalyst A is one or more of alumina, cerium dioxide, zirconium dioxide, titanium dioxide and silicon dioxide; the molecular sieve is one or more of A-type, Y-type, Beta, ZSM-5, TS-1 and MCM-41 molecular sieves; the specific surface area of the activated carbon is 50-3000m2A pore volume of 0.1-2.5 cm3The active carbon-containing material has an average pore diameter of 0.2-10 nm, wherein the active carbon content is 8-100 wt%.
In the method for treating wastewater by ozone catalytic wet oxidation, the catalyst A can also comprise an auxiliary agent, and the auxiliary agent is one or more of lanthanum, cerium, praseodymium and neodymium.
In the method for treating wastewater by ozone catalytic wet oxidation, the active metal component in the catalyst B is one or more of transition metals Fe, Cu, Mn, Ti and Zn, and the transition metal accounts for 0.1-20.0% of the total mass of the catalyst in terms of oxide.
In the method for treating wastewater by ozone catalytic wet oxidation, the catalyst B also comprises an auxiliary agent component, wherein the auxiliary agent component is a rare earth metal, and the rare earth metal is one or more of lanthanum, cerium, praseodymium and neodymium; the rare earth metal accounts for 0.1 to 15.0 percent of the total mass of the catalyst by oxide.
In the method for treating wastewater by ozone catalytic wet oxidation, the activated carbon used in the catalyst B is powdered activated carbon, the granularity is 150-300 meshes, and the specific surface area is 500-3000 m2A pore volume of 0.5-1.8 cm3(ii)/g, the average pore diameter is 0.5 to 4.0nm, and the pore volume of pores having a pore diameter of 1 to 2nm accounts for 90% or more of the total pore volume.
In the method for treating wastewater by ozone catalytic wet oxidation, the activated carbon in the catalyst B can be selected from conventional powdery activated carbon commodities, such as various wood activated carbons, shell activated carbons and coal-based activated carbons; or can be selected from various activated carbon products obtained by conventional preparation methods of wood materials, mineral materials, plastics and wastes, such as wood, sawdust, charcoal, coconut shells, fruit pits, fruit shells, coal carbon, coal gangue, petroleum coke, petroleum pitch, polyvinyl chloride, polypropylene, organic resin, waste tires, residual sludge and the like.
In the method for treating wastewater by ozone catalytic wet oxidation, the properties of the composite carrier in the catalyst B are as follows: the specific surface area is 150-1500 m2A pore volume of 0.1 to 1.2 cm/g3G, average pore size 1 ℃8nm。
In the method for treating wastewater by ozone catalytic wet oxidation, the property of the catalyst B is as follows: the specific surface area is 120-1200 m2A pore volume of 0.1 to 1.8 cm/g3G, abrasion Rate<3wt% and a side pressure strength of 80 to 250N/cm.
In the method for treating wastewater by ozone catalytic wet oxidation, when the alkali carbonate in the catalyst B is a mixture of basic calcium carbonate and basic magnesium carbonate, the basic carbonate and the basic magnesium carbonate can be mixed in any proportion.
In the method for treating wastewater by ozone catalytic wet oxidation, the preparation method of the catalyst B comprises the following steps:
(1) mixing activated carbon and a soluble organic salt solution uniformly to obtain a material A, wherein the soluble organic salt solution is a soluble organic magnesium salt solution or a mixed solution of a soluble organic calcium salt solution and a soluble organic magnesium salt solution;
(2) introducing a carbonate solution or an alkaline solution into the material A obtained in the step (1), uniformly mixing, and standing to obtain a material B;
(3) performing solid-liquid separation on the material B obtained in the step (2), and drying and roasting a solid phase obtained by separation to obtain a material C;
(4) mixing the material C obtained in the step (3) with water, introducing carbon dioxide gas for reaction, cooling, performing solid-liquid separation, and drying and roasting a solid phase obtained by separation to obtain a composite carrier;
(5) and (4) impregnating active metal and optional auxiliary agent components on the composite carrier material obtained in the step (4), and then drying and roasting to obtain the catalyst.
In the preparation method of the catalyst B, the activated carbon used in the step (1) is powdered activated carbon, the granularity is 150-300 meshes, and the specific surface area is 500-3000 m2A pore volume of 0.5-1.8 cm3(ii)/g, the average pore diameter is 0.5 to 4.0nm, and the pore volume of pores having a pore diameter of 1 to 2nm accounts for 90% or more of the total pore volume. The activated carbon can be selected from conventional powdered activated carbon commercial products, such as various wood activated carbon and fruitShell activated carbon, coal-based activated carbon; or can be selected from various activated carbon products obtained by conventional preparation methods of wood materials, mineral materials, plastics and wastes, such as wood, sawdust, charcoal, coconut shells, fruit pits, fruit shells, coal carbon, coal gangue, petroleum coke, petroleum pitch, polyvinyl chloride, polypropylene, organic resin, waste tires, residual sludge and the like.
In the preparation method of the catalyst B, the soluble organic calcium salt in the step (1) is one or more of calcium gluconate, calcium acetate, calcium lactate, calcium amino acid, calcium L-aspartate and calcium L-threonate, and preferably calcium gluconate or calcium lactate is used.
In the preparation method of the catalyst B, the soluble organic magnesium salt in the step (1) is one or more of magnesium gluconate, magnesium acetate, magnesium lactate, magnesium amino acid, magnesium L-aspartate and magnesium L-threonate, and preferably magnesium gluconate or magnesium lactate is adopted.
In the preparation method of the catalyst B, the activated carbon and the soluble organic salt in the step (1) are mixed according to the ratio of C: m2+The molar ratio is 4.3-84.7: 1, and the ratio of C: m2+The molar ratio is 10-60: 1, wherein M represents Mg or Ca and Mg.
In the preparation method of the catalyst B, the carbonate in the step (2) is one or more of ammonium carbonate, potassium carbonate and sodium carbonate, preferably ammonium carbonate; the concentration of the carbonate solution is 0.1-1.0 mol/L.
In the preparation method of the catalyst B, the carbonate is used in the step (2) in an amount of CO3 2-:M2+The molar ratio is 1-1.2: 1, and CO is preferably selected3 2-:M2+The molar ratio is 1: 1.
In the preparation method of the catalyst B, the alkaline solution in the step (2) is an inorganic alkaline solution, and specifically may be ammonia, sodium hydroxide or potassium hydroxide.
In the preparation method of the catalyst B, in the step (2), an alkaline solution is introduced into the material A obtained in the step (1), and then the pH value is adjusted to 8-9.
In the preparation method of the catalyst BThe dosage of the alkaline solution in the step (2) is OH-:M2+The molar ratio is 2-4: 1, and OH is preferred-:M2+The molar ratio is 2-2.5: 1, wherein M represents Mg or Ca and Mg.
In the preparation method of the catalyst B, the drying temperature in the step (3) is 70-110 ℃, preferably 80-100 ℃, and the drying time is 2-6 hours, preferably 3-4 hours.
In the preparation method of the catalyst B, the calcination in the step (3) is carried out in nitrogen or inert atmosphere, wherein the inert atmosphere is one of argon and helium. In the step (3), the roasting temperature is 500-1200 ℃, preferably 600-900 ℃, and the roasting time is 2-8 hours, preferably 3-5 hours.
In the preparation method of the catalyst B, the material C in the step (4) is mixed with water at the temperature of 60-100 ℃.
In the preparation method of the catalyst B, the partial pressure of the carbon dioxide in the step (4) is 0.08-1.0 MPa.
In the preparation method of the catalyst B, the reaction end point pH in the step (4) is 7.0-10.0, preferably 8.0-9.0.
In the preparation method of the catalyst B, the reaction temperature in the step (4) is 15-150 ℃.
In the preparation method of the catalyst B, the drying temperature in the step (4) is 40-100 ℃, preferably 40-60 ℃, and the drying time is 3-24 hours, preferably 6-8 hours.
In the preparation method of the catalyst B, the calcination in the step (4) is carried out in nitrogen or inert atmosphere, wherein the inert atmosphere is one of argon and helium. In the step (4), the roasting temperature is 80-220 ℃, the roasting time is 2-6 h, and the roasting time is preferably 3-4 h, wherein the roasting time is preferably 150-200 ℃.
In the above preparation method of the catalyst B, the solid-liquid separation in the steps (3) and (4) can adopt any scheme capable of realizing solid-liquid separation in the field, such as solid-liquid separation by filtration.
In the preparation method of the catalyst B, when the active metal component and the optional auxiliary component are impregnated on the composite carrier material obtained in the step (4) in the step (5), the composite carrier material obtained in the step (4) is preferably prepared and molded first, and then the active metal component and the optional auxiliary component are impregnated on the composite carrier material, the molding technology of the composite carrier adopts any technology which can realize molding in the prior art, and the shape of the molded carrier is any one of a cylinder, a hollow cylinder, a clover shape and a sphere.
In the preparation method of the catalyst B, the active metal component in the step (5) is one or more of transition metals Fe, Cu, Mn, Ti and Zn, and the transition metals account for 0.1-20.0% of the total mass of the catalyst in terms of oxides.
In the preparation method of the catalyst B, the auxiliary agent component in the step (5) is rare earth metal, and the rare earth metal oxide accounts for 0.1-15.0% of the total mass of the catalyst. The rare earth metal is one or more of lanthanum, cerium, praseodymium and neodymium.
In the above method for preparing catalyst B, the carrier-impregnated active metal and the auxiliary component in step (5) may be spray-impregnated, or saturated-impregnated, or supersaturated-impregnated. When in impregnation, the impregnation sequence of the active metal and the auxiliary agent has no special requirements.
In the preparation method of the catalyst B, after the catalyst is impregnated in the step (5), the catalyst is dried for 1-15 hours under the drying condition of 40-100 ℃, the roasting temperature is 100-220 ℃, and the roasting time is 1-10 hours. The calcination is carried out in a nitrogen or inert atmosphere.
In the method for treating wastewater by ozone catalytic wet oxidation, the reaction temperature in the reactor is 0-50 ℃, and preferably 20-30 ℃; the reaction pressure was normal pressure.
According to the method for treating the wastewater by ozone catalytic wet oxidation, the retention time of the organic wastewater in the catalyst bed layer is 10-300 minutes.
In the method for treating wastewater by ozone catalytic wet oxidation, the ozone dosage is 0.3-2.0 times of the oxidant dosage calculated according to the original organic wastewater COD value.
According to the method for treating the wastewater by ozone catalytic wet oxidation, the COD of the organic wastewater is 10-10000 mg/L, and the wastewater can be any one or more of dye wastewater, petrochemical wastewater and coal chemical wastewater.
In the method for treating the wastewater by ozone catalytic wet oxidation, the wastewater is firstly contacted with a catalyst A loaded by an oxide, a molecular sieve or an active carbon carrier in the presence of ozone, the initial concentration of the ozone is higher, partial ozone is generated under the action of the catalyst A, and OH converts a part of organic pollutants; the concentration of downstream ozone is reduced, and then the downstream ozone is contacted with a catalyst B loaded by an active carbon composite carrier with stronger catalytic ozone decomposition capability, so that the catalytic action of the active carbon, the metal active component and hydroxyl on the surface of the basic phosphate for catalyzing the decomposition of ozone to generate OH is fully exerted; through the synergistic effect of sectional treatment of the oxide, the molecular sieve or the activated carbon carrier-loaded catalyst A and the activated carbon composite carrier-loaded catalyst B according to the ozone concentration gradient, the organic wastewater treatment effect is good, the effective utilization rate of ozone can be greatly improved, the ozone adding amount is reduced, and the problem of low effective utilization rate of ozone in the prior art is solved. Compared with the prior art, the method maintains higher COD removal effect of the organic wastewater by adopting a catalyst grading method, improves the effective utilization rate of ozone, reduces the adding amount of the ozone, has higher reaction activity and use stability, and is particularly suitable for catalytic oxidation reaction of the ozone. The method has simple and convenient process, is easy to operate and is suitable for industrial application.
In the method for treating wastewater by ozone catalytic wet oxidation, the catalyst B adopts a novel composite carrier, and the basic magnesium carbonate or the basic calcium carbonate and the basic magnesium carbonate is introduced into the outer surface of the active carbon in the composite carrier, so that compared with a pure active carbon carrier, the relative content of the active carbon in the carrier is reduced, the utilization rate of free radicals can be improved, and the problems that the generation of hydroxyl free radicals is accelerated due to the overhigh content of the active carbon in the existing pure active carbon catalyst, the collision probability among the free radicals is increased, and the concentration of the free radicals is weakened are solved. Hydroxyl contained in the basic calcium carbonate and the basic magnesium carbonate is introduced into the outer surface of the composite carrier, so that the decomposition of ozone is promoted to generate hydroxyl radicals, a free radical chain reaction is further initiated, and the utilization efficiency of the hydroxyl radicals can be improved to the maximum degree by controlling the content of the hydroxyl radicals by adjusting the content of the basic magnesium carbonate or the basic calcium carbonate and the basic magnesium carbonate. When the active metal supported active carbon composite carrier is used for wastewater treatment, the basic calcium carbonate and the basic magnesium carbonate can adsorb active metal ions dissolved out from the catalyst, so that secondary pollution caused by the active metal ions is avoided.
In the preparation of the composite carrier of the catalyst B, the macromolecular organic magnesium salt or the macromolecular organic calcium salt and macromolecular organic magnesium salt solution is mixed with the active carbon, and molecules of the macromolecular organic calcium salt and the macromolecular organic magnesium salt are difficult to enter into the pore channels of the active carbon, so that calcium ions and magnesium ions are ensured to be almost completely attached to the surface of the active carbon, the organic calcium salt and organic magnesium salt solution is prevented from entering into the pore channels of the active carbon, and the generated basic calcium carbonate and basic magnesium carbonate can be prevented from blocking the pore channels and influencing the performance of the carrier. The preparation process of the composite carrier is an in-situ generation process of organic calcium salt/organic magnesium salt-calcium carbonate/magnesium (calcium hydroxide/magnesium) -basic calcium carbonate/magnesium, the basic calcium carbonate/magnesium is firmly attached to the outer surface of the active carbon, the mechanical mixing of the active carbon and the basic calcium carbonate/magnesium is more uniform and firm, and the defect that pore channels are blocked due to in-situ generation in pores is avoided. Meanwhile, organic components in the organic calcium/magnesium salt can generate part of carbon in the roasting stage, the part of carbon can play a role of an adhesive, and the generated calcium/magnesium salt is organically connected with the original activated carbon carrier, so that the firmness between the basic calcium/magnesium carbonate and the activated carbon in the composite carrier is improved, the strength of the formed carrier is enhanced, and the abrasion is reduced.
Detailed Description
The method for treating wastewater by ozone catalytic wet oxidation according to the present invention will be further described with reference to the following specific examples, but the scope of the present invention is not limited to these examples.
In the ozone oxidation reaction, it is generally believed that only one oxygen atom in ozone participates in the reaction, so 3g of ozone is theoretically required for removing 1g of COD, the numerator "COD removal × 3" in the above formula represents the theoretical requirement amount of ozone, and the denominator "(inlet ozone concentration-outlet ozone concentration) × gas flow rate" in the above formula represents the actual usage amount of ozone.
The effective utilization rate of the ozone is as follows: the ozone used for the decomposition of organic pollutants is a percentage of the total ozone consumed.
Preparation of catalyst A1
Kneading, rolling and extruding macroporous alumina powder and peptizing agent to prepare clover-shaped carrier with the diameter of 2.5mm, and roasting in air at 550 ℃ to prepare Al2O3Support, specific surface area 220 m2G, pore volume 0.7 cm3G, average pore diameter of 10.4 nm. 500g of alumina carrier is weighed and Fe (NO) is used according to the water absorption rate3)3·9H2O is Fe2O3The catalyst accounts for 7.5 percent of the total weight of the catalyst to prepare solution. The alumina carrier is soaked in the solution in the same volume for 2 hours, dried at 80 ℃, then roasted in a muffle furnace at 550 ℃ for 4 hours, and taken out after the temperature is reduced to room temperature, thus obtaining the catalyst A1.
Preparation of catalyst A2
The diameter of the mixture is 2.0mm, the specific surface area is 100 m2G, pore volume 0.4 cm3TiO bars with a mean pore diameter of 3.4 nm/g2The carrier is dried at 120 ℃ for standby. RuCl according to its water absorption3The solution is prepared according to the proportion that Ru accounts for 2 percent of the total weight of the catalyst. Isovolumetric impregnation of TiO with Ru solution2The carrier is dried at 100 deg.C for 24 hr, and then put into a tube furnace, and the carrier is dried at 400 deg.C with 10% H2N of (A)2Reducing for 4 hours, and then using the catalyst containing 1% of O2N of (A)2After deactivation for 4 hours, the temperature was lowered to room temperature and taken out to obtain catalyst A2.
Preparation of catalyst A3
The diameter of the mixture is 2.0mm, the specific surface area is 320m2G, pore volume 0.3cm3Per g, pingCommercial ZSM-5 molecular sieve strip-shaped carrier with the average pore diameter of 2.4nm is dried at 120 ℃ for later use. Weighing 500g of ZSM-5 molecular sieve carrier, and using Fe (NO) according to the water absorption rate3)3·9H2O is Fe2O3The catalyst is prepared into 1000mL solution according to the proportion of 7.5 percent of the total weight of the catalyst. The ZSM-5 carrier is soaked in the solution in the same volume, stirred in a constant temperature water bath for 3 hours at 60 ℃, kept stand in the air for 24 hours, evaporated to dryness in a rotary evaporator at 80 ℃ in vacuum, and the obtained sample is dried in a drying box at 100 ℃. Then, the catalyst was calcined at 550 ℃ for 4 hours in a muffle furnace, and the temperature was lowered to room temperature and taken out to obtain a catalyst A3.
Preparation of catalyst A4
The diameter of the mixture is 2.0mm, the specific surface area is 432m2G, pore volume 0.2 cm3Drying the TS-1 molecular sieve strip carrier with the average pore diameter of 3.3nm at 120 ℃ for later use. Weighing 500g of TS-1 molecular sieve carrier and using Cu (NO)3)2·3H2O and Ce (NO)3)3·6H2O as CuO and CeO21000mL of solution was prepared in proportions of 6% and 1.5% of the total weight of the catalyst, respectively. And (3) soaking the TS-1 carrier for 3 hours by using a Cu-Ce solution, standing in the air for 24 hours, then evaporating to dryness in vacuum at 80 ℃ by using a rotary evaporator, and drying the obtained sample in a drying oven at 100 ℃. Then, the catalyst was calcined at 550 ℃ for 4 hours in a muffle furnace, and the temperature was lowered to room temperature and taken out to obtain a catalyst A4.
Preparation of catalyst A5
The diameter of the mixture is 1.7mm, the specific surface area is 320m2G, pore volume 0.3cm3And drying the self-made strip-shaped activated carbon carrier with the average pore diameter of 1.9nm and the carbon content of 45% at 120 ℃ for later use. Weighing 500g of dried activated carbon strip, and using Cu (NO)3)2·3H2O and Ce (NO)3)3·6H2O as CuO and CeO2The catalyst is prepared into solution respectively accounting for 5 percent and 1.5 percent of the total weight of the catalyst. Soaking the activated carbon strips in the solution for 2 hours in the same volume, drying at 80 ℃, roasting for 4 hours at 550 ℃ in a nitrogen atmosphere, cooling to room temperature, and taking out to obtain the catalyst A5.
Preparation of catalyst A6
The diameter of the mixture is 2.5mm, and the specific surface area is 204m2G, pore volume 0.3cm3Per g, average poreDrying the self-made strip-shaped activated carbon carrier with the diameter of 2.0 nm and the carbon content of 25% at 120 ℃ for later use. Weighing 500g of dried activated carbon strips, and using RuCl according to the water absorption rate of the activated carbon strips3The solution is prepared according to the proportion that Ru accounts for 2 percent of the total weight of the catalyst. Soaking active carbon carrier in Ru solution for 24 hr, stoving at 100 deg.c, setting in tubular furnace, and soaking in 10% H solution at 400 deg.c2N of (A)2Reducing for 4 hours, and then using the catalyst containing 1% of O2N of (A)2After deactivation for 4 hours, the temperature was lowered to room temperature and taken out to obtain catalyst A6.
Preparation of catalyst B1
Adding 50g of activated carbon powder into 250g of L magnesium lactate solution with the mass fraction of 19.2%, slowly stirring, and soaking for 4 hours; slowly adding 270mL of ammonium carbonate solution with the concentration of 0.7mol/L dropwise under stirring to generate magnesium carbonate precipitate, stirring, standing for 2 hours, filtering, drying at 80 ℃ for 12 hours, and roasting at 1100 ℃ for 3 hours under the protection of nitrogen to obtain the activated carbon-magnesium oxide compound. Adding the obtained compound into 200g of distilled water with the temperature of 85 ℃, introducing CO after 2h2And (3) controlling the end point pH to be 8.0 at 90 ℃ under the pressure of 0.36MPa, naturally cooling, filtering, drying at 70 ℃ for 8h, and roasting at 200 ℃ for 2h under the protection of argon to obtain the activated carbon and basic magnesium carbonate composite carrier material. The obtained carrier material is made into clover shape with the diameter of 2.5mm, dried at 70 ℃, and roasted under the protection of nitrogen to obtain the catalyst carrier. With Zn (NO)3)2·6H2O and Ce (NO)3)3·6H2O as ZnO and CeO2The catalyst is prepared into 1000mL solution according to the proportion of 2.0 percent and 10.5 percent of the total weight of the catalyst respectively. And (3) supersaturating and impregnating the carrier strip with a Zn-Ce solution, stirring for 3 hours at 60 ℃ in a constant-temperature water bath, standing for 24 hours in the air, then evaporating to dryness in vacuum at 80 ℃ by using a rotary evaporator, and drying the obtained sample in a drying box at 100 ℃. Then roasting the mixture for 6 hours at 150 ℃ under the protection of nitrogen, and taking out the mixture after the temperature is reduced to room temperature to obtain the catalyst B1.
Preparation of catalyst B2
Adding 100g of activated carbon powder into 300g of a magnesium L-aspartate solution with the mass fraction of 10%, slowly stirring, and soaking for 4 hours; slowly dropwise adding 210mL of 1.0mol/L ammonia water under stirring to generate magnesium carbonate precipitateStirring, standing for 2 hours, filtering, drying at 80 ℃ for 12 hours, and roasting at 1100 ℃ for 3 hours under the protection of nitrogen to obtain the activated carbon-magnesium oxide compound. Adding the obtained compound into 200g of distilled water with the temperature of 90 ℃, introducing CO after 1h2And (3) controlling the end point pH to be 9.0 at the temperature of 110 ℃ under the pressure of 0.15MPa, naturally cooling, filtering, drying at 70 ℃ for 8h, and roasting at 200 ℃ for 2h under the protection of argon to obtain the activated carbon and basic magnesium carbonate composite carrier material. The obtained carrier material is prepared into clover shape with the grain diameter of 2.5mm, dried at 70 ℃, and roasted under the protection of nitrogen to obtain the catalyst carrier. With Mn (NO)3)2·4H2O and La (NO)3)3·6H2Oto MnO2And La2O31000mL of solution was prepared in proportions of 1.5% and 8.5% of the total weight of the catalyst, respectively. And (3) supersaturating and dipping the carrier strip by using a Mn-La solution, stirring for 3 hours at 60 ℃ in a constant-temperature water bath, standing for 24 hours in the air, then evaporating to dryness in vacuum at 80 ℃ by using a rotary evaporator, and drying the obtained sample in a drying box at 100 ℃. Then roasting the mixture for 6 hours at 150 ℃ under the protection of nitrogen, and taking out the mixture after the temperature is reduced to room temperature to obtain the catalyst B2.
Preparation of catalyst B3
Adding 100g of activated carbon powder into 300g of mixed solution of 14.6 percent of magnesium gluconate and 5.1 percent of L-calcium lactate in mass fraction, slowly stirring and soaking for 4 hours; slowly dropwise adding 200mL of 0.8mol/L sodium carbonate solution under stirring to generate carbonate precipitate, stirring, standing for 2 hours, filtering, drying at 80 ℃ for 12 hours, and roasting at 1100 ℃ for 3 hours under the protection of nitrogen to obtain the activated carbon-magnesium oxide-calcium oxide compound. Adding the obtained compound into 200g of distilled water with the temperature of 90 ℃, introducing CO after 1h2And (3) controlling the end point pH to be 7.7 under the conditions of gas pressure of 0.30MPa and temperature of 140 ℃, naturally cooling, filtering, drying at 50 ℃ for 6 hours, and roasting at 140 ℃ for 4 hours under the protection of nitrogen to obtain the activated carbon, basic magnesium carbonate and basic calcium carbonate composite carrier material. The obtained carrier material is made into clover shape with the diameter of 2.5mm, dried at 70 ℃, and roasted under the protection of nitrogen to obtain the catalyst carrier. According to its water absorption rate, Fe (NO)3)3·9H2O and Ce (NO)3)3·6H2O is Fe2O3And CeO2The catalyst is prepared into solution respectively accounting for 5.0 percent and 1.5 percent of the total weight of the catalyst. And (3) soaking the carrier strip with Fe-Ce solution in the same volume for 2 hours, drying at 80 ℃, roasting for 6 hours at 180 ℃ in a nitrogen atmosphere, cooling to room temperature, and taking out to obtain the catalyst B3.
Preparation of catalyst B4
Adding 50g of activated carbon powder into 300g of mixed solution of 12.8 percent of magnesium L-aspartate and 6.3 percent of calcium acetate respectively, slowly stirring and soaking for 4 hours; slowly dropwise adding 570mL of potassium hydroxide solution with the concentration of 0.9mol/L under stirring to generate hydroxide precipitate, stirring, standing for 2 hours, filtering, drying at 80 ℃ for 12 hours, and roasting at 1100 ℃ for 3 hours under the protection of nitrogen to obtain the activated carbon-magnesium oxide-calcium oxide compound. Adding the obtained compound into 200g of distilled water with the temperature of 85 ℃, introducing CO after 2h2And (3) controlling the end point pH to be 8.5 under the conditions of gas pressure of 0.26MPa and temperature of 120 ℃, naturally cooling, filtering, drying at 70 ℃ for 4h, and roasting at 160 ℃ for 3h under the protection of nitrogen to obtain the activated carbon, basic magnesium carbonate and basic calcium carbonate composite carrier material. The obtained carrier material is made into a cylindrical shape with the diameter of 2.5mm, dried at 70 ℃, and then roasted under the protection of nitrogen to obtain the catalyst carrier. With 50% Mn (NO)3)2·4H2O solution and Ce (NO)3)3·6H2Oto MnO2And CeO2The catalyst is prepared into 1000mL solution according to the proportion of 6.0 percent and 1.5 percent of the total weight of the catalyst respectively. And (3) supersaturating and impregnating the carrier strip with a Mn-Ce solution, stirring for 3 hours at 60 ℃ in a constant-temperature water bath, standing for 24 hours in the air, then evaporating to dryness in vacuum at 80 ℃ by using a rotary evaporator, and drying the obtained sample in a drying box at 100 ℃. Then roasting the mixture in a muffle furnace at 190 ℃ for 4 hours, and taking out the mixture after the temperature is reduced to room temperature to obtain the catalyst B4.