A catalyst for treating chemical wastewater and a preparation method thereof

Abstract

The present application relates to the field of chemical wastewater treatment catalyst, especially to a kind of chemical wastewater treatment catalyst and its preparation method.The chemical wastewater treatment catalyst, by mass percentage, raw material includes: molecular sieve 5-15%, metal oxide 10-60%, inorganic metal salt 0-20%, and carbon material makes up the rest.The present application provides catalyst, which can be effectively used in the process of wastewater treatment by ozone catalytic oxidation, can effectively remove organic matter in wastewater, especially organic hydrocarbon substances, adsorb part of inorganic matter, has excellent research university and research institute wastewater treatment applicability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical wastewater treatment catalysts, in particular to a chemical wastewater treatment catalyst and a preparation method thereof. BACKGROUND

[0002] With the continuous enhancement of people's and social environmental protection awareness and the increasingly strict environmental protection standards of enterprises, the effective treatment of three wastes has once again become a problem that each enterprise must face. Among them, the wastewater pollution problem in the chemical industry is the most serious. In recent years, each enterprise has optimized the wastewater discharge and recycling treatment mode, and the corresponding wastewater treatment process and supporting technology have made obvious progress. However, in the daily scientific experiments of petroleum and chemical research institutes, research-oriented colleges and universities and research sites of enterprises, the waste liquid containing chemical reagents is usually classified and recycled and directed to be treated, but the wastewater containing organic molecules such as hydrocarbons generated in the process of cleaning the experimental glassware and instrument equipment is inevitably discharged into the sewage pipe. This kind of wastewater has the characteristics of high organic matter concentration and difficult degradation compared with traditional industrial wastewater.

[0003] The prior art, Chinese patent CN109569596B discloses a catalyst for treating wastewater containing ammonia nitrogen and COD, which comprises platinum group noble metal, group IVA metal and oxide carrier, and is used at a reaction temperature of 260℃ and a pressure of 8.5MPa. However, this invention requires a certain temperature and pressure, which has excellent economy when discharging traditional industrial wastewater, but for wastewater with organic hydrocarbon as the main pollutant and intermittent discharge, the efficiency is low and the economic cost is high. Chinese patent CN102872884B discloses a water treatment catalyst, its production method and application, the raw materials include manganese dioxide, aluminum oxide, carbon dioxide, cobalt trioxide, carbon powder, etc. However, the catalyst has the problems of small specific surface area, low mechanical strength, easy ozone activation, low catalytic degradation efficiency, etc.

[0004] Therefore, in order to solve the above problems, the present application provides a chemical wastewater treatment catalyst which can be effectively applied to scientific research institutes, research laboratories of enterprises and laboratories of colleges and universities. SUMMARY

[0005] In order to solve the above problems, the present application provides a chemical wastewater treatment catalyst, and the raw materials include, in mass percentage: 5-15% of molecular sieve, 10-60% of metal oxide, 0-20% of inorganic metal salt, and the balance of carbon material.

[0006] As a preferred scheme, the chemical wastewater treatment catalyst, in mass percentage, comprises 10-15% of molecular sieve, 20-55% of metal oxide, 10-20% of inorganic metal salt, and the rest of carbon material.

[0007] As a preferred scheme, the dry base of the molecular sieve is ≥95%; the specific surface area of the molecular sieve is 500-800 m 2 / g; the pore volume of the molecular sieve is 0.3-0.5 cm 3 / g, and the mesopore ratio is 40-80%.

[0008] As a preferred scheme, the specific surface area of the molecular sieve is 600-800 m 2 / g; the pore volume of the molecular sieve is 0.3-0.4 cm 3 / g, and the mesopore ratio is 45-55%.

[0009] As a preferred scheme, the specific surface area of the molecular sieve is 650 m 2 / g; the pore volume of the molecular sieve is 0.5 cm 3 / g, and the mesopore ratio is 48%.

[0010] As a preferred scheme, the metal oxide is at least two of aluminum oxide, zinc oxide, titanium dioxide, iron oxide, ferrous oxide, manganese dioxide, calcium oxide, and magnesium oxide.

[0011] As a preferred scheme, the dry base of the aluminum oxide is ≥70%; the specific surface area of the aluminum oxide is 300-500 m 2 / g, and the pore volume is 0.5-1.2 cm 3 / g.

[0012] As a preferred scheme, the specific surface area of the aluminum oxide is 400-500 m 2 / g, and the pore volume is 0.6-0.8 cm 3 / g.

[0013] As a preferred scheme, the metal oxide at least comprises aluminum oxide; the mass ratio of the aluminum oxide to the molecular sieve and the inorganic metal salt is 18-20:12-15:10-15.

[0014] As a preferred scheme, the mass ratio of the aluminum oxide to the molecular sieve and the inorganic metal salt is 20:15:15.

[0015] As a preferred scheme, the inorganic metal salt is at least one of copper sulfate, iron sulfate, copper nitrate, iron nitrate, and sodium phosphate.

[0016] As a preferred scheme, the inorganic metal salt is copper sulfate.

[0017] As a preferred scheme, the molecular sieve is a modified Y molecular sieve or a beta molecular sieve.

[0018] As a preferred scheme, the carbon material is at least one of graphene, graphene oxide, carbon nanotube, and activated carbon powder.

[0019] As a preferred scheme, the carbon material is activated carbon powder; and the activated carbon powder is coconut shell activated carbon powder.

[0020] The second aspect of the present application provides a preparation method of the chemical wastewater treatment catalyst, and the steps include the following steps: (1) dissolving an inorganic metal salt in water to form a weakly acidic aqueous solution, then adding alumina into the inorganic metal salt aqueous solution and stirring uniformly, then adding a molecular sieve and stirring to a gel state, and after drying treatment, crushing the blocky solid; (2) mixing the crushed material in step (1) with remaining oxides and a carbon material, and adding the mixture into deionized water according to a mass-to-water ratio and extruding into a strip under mechanical pressure; (3) drying the formed product, breaking the strip, and calcining in a nitrogen environment, and after completion, the catalyst is obtained.

[0021] As a preferred scheme, the mass-to-water ratio of the mixture to deionized water is 1:0.8-1.2.

[0022] As a preferred scheme, the mass-to-water ratio of the mixture to deionized water is 1:1.

[0023] In the present application, the preparation of the pre-gel mixture is performed, and the mass ratio of the preparation raw material alumina to the molecular sieve and the inorganic metal salt is limited, so that the performance of the catalyst is effectively improved. The present applicant believes that when the mass ratio of the alumina to the molecular sieve and the inorganic metal salt is 20:15:15, the alumina, the molecular sieve, and the copper sulfate solution can form a gel structure with effective bonding effect under the joint action, which can further promote the stable combination of the active phase of the copper sulfate, the molecular sieve with a specific specific surface area and pore size structure, and the alumina in the preparation process of the catalyst, and in the subsequent extrusion molding stage, the catalyst can help to promote the connection relationship between the multiple raw materials in the catalyst, thereby having excellent mechanical strength.

[0024] The third aspect of the present application provides an application of the above-mentioned chemical wastewater treatment catalyst, including the application of the chemical wastewater treatment catalyst in the treatment of research chemical wastewater and petroleum chemical wastewater recovery treatment process.

[0025] Advantages:

[0026] 1. The chemical wastewater treatment catalyst can be effectively used in the ozone catalytic oxidation wastewater treatment process, can effectively remove organic matter in wastewater, especially organic hydrocarbon substances, and can adsorb part of inorganic matter, has excellent research and institute wastewater treatment applicability.

[0027] 2. The chemical wastewater treatment catalyst can avoid the specific pressure and temperature conditions required by the existing wastewater treatment, can be flexibly used in the interval discharge of small test sites, avoids the high wastewater treatment cost, and can effectively control the wastewater treatment cost of small test sites.

[0028] 3. The chemical wastewater treatment catalyst has high specific surface area and high mechanical strength, can effectively avoid the problems of ozone activation and catalytic efficiency reduction, has a long service life and excellent applicability.

[0029] 4. The chemical wastewater treatment catalyst can enhance the adsorption performance of organic molecules and part of inorganic molecules in the process of ozone oxidation treatment of wastewater, and can remove inorganic molecules in the process of strengthening oxidation reaction.

[0030] 5. The chemical wastewater treatment catalyst is prepared by dissolving copper sulfate in water to form a weak acidic aqueous solution, then adding a certain amount of alumina and molecular sieve into the copper sulfate aqueous solution to form a gel, and the alumina, molecular sieve and copper sulfate solution can form a gel tissue with effective bonding effect under the joint action, which can further promote the active phase of copper sulfate, the molecular sieve with specific specific surface area and pore size structure and the alumina to form a stable combination relationship in the preparation process of the catalyst, and in the subsequent extrusion molding stage, the catalyst can help to promote the connection relationship between the internal raw materials, thereby having excellent mechanical strength. DETAILED DESCRIPTION

[0031] Example 1

[0032] The first aspect provides a chemical wastewater treatment catalyst, and the raw materials include: modified Y molecular sieve 15%, alumina 20%, copper sulfate 15%, iron oxide 18%, and coconut shell activated carbon powder supplementing the balance in mass percentage.

[0033] The dry base of the molecular sieve of the modified Y molecular sieve is 95.5%; the specific surface area of the modified Y molecular sieve is 650m 2 / g, the pore volume is 0.45cm 3 / g, and the mesopore ratio is 48%.

[0034] The dry base of the alumina is 75%, the specific surface area is 450 m 2 / g, and the pore volume is 0.72 cm 3 / g.

[0035] The modified Y molecular sieve is purchased from Shanghai Xinnian Petrochemical Additive Co., Ltd. WUSY-7 molecular sieve.

[0036] The alumina is purchased from Binzhou Poly New Material Co., Ltd. (P8).

[0037] The iron oxide is purchased from Sinopharm (Shanghai Test).

[0038] The coconut shell activated carbon powder is purchased from Dongguan Junmao Environmental Protection Technology Co., Ltd. (Activated Carbon).

[0039] The average particle sizes of the alumina, the modified Y molecular sieve, and the copper sulfate are 50 mesh, 60 mesh, and 60 mesh, respectively.

[0040] The second aspect of the embodiment provides a preparation method of the above-mentioned catalyst, and the steps include the following steps: (1) dissolving the copper sulfate in water to form a weak acidic aqueous solution, then adding the alumina into the copper sulfate aqueous solution and stirring uniformly, then adding the modified Y molecular sieve and stirring to a gelation state, and after drying treatment, crushing the blocky solid; (2) mixing the crushed material of step (1) with the iron oxide and the coconut shell activated carbon powder, and adding the mixture into deionized water according to the mass water powder ratio and extruding into strips under mechanical pressure; (3) drying, breaking the strips, and roasting in a nitrogen environment, and after completion, the product is obtained.

[0041] Among them, the mass water powder ratio of the mixture to deionized water is 1:1.

[0042] Example 2

[0043] The specific implementation manner of the embodiment is the same as that of embodiment 1, except that the chemical wastewater treatment catalyst includes, in terms of mass percentage, the modified Y molecular sieve 12%, the alumina 18%, the copper sulfate 12%, the titanium dioxide 20%, and the coconut shell activated carbon powder to make up the balance.

[0044] The titanium dioxide is purchased from Sinopharm (Shanghai Test).

[0045] Example 3

[0046] The specific implementation manner of the embodiment is the same as that of embodiment 1, except that the chemical wastewater treatment catalyst includes, in terms of mass percentage, the modified Y molecular sieve 15%, the alumina 20%, the copper sulfate 10%, the manganese dioxide 5%, the iron oxide 12%, and the coconut shell activated carbon powder to make up the balance.

[0047] The manganese dioxide is purchased from Sinopharm (Shanghai Test).

[0048] Example 4

[0049] The specific implementation of the embodiment is the same as that of Example 3, except that the chemical wastewater treatment catalyst comprises, in mass percentage, beta molecular sieve 12%, alumina 20%, copper sulfate 12%, manganese dioxide 6%, iron oxide 12%, and coconut shell activated carbon powder to make up the balance.

[0050] In the preparation method, instead of extruding under mechanical pressure in step (2), granulation in a granulator is selected, and the particle size of the granules is 4 mm.

[0051] The beta molecular sieve is purchased from Shandong Qilu Huaxin Gaokeli Co., Ltd. Beta-B.

[0052] Comparative Example 1

[0053] The specific implementation of the embodiment is the same as that of Example 1, except that the chemical wastewater treatment catalyst comprises, in mass percentage, alumina 32%, modified Y molecular sieve 12%, manganese dioxide 6%, iron oxide 12%, and coconut shell activated carbon powder to make up the balance.

[0054] In the preparation method, instead of extruding under mechanical pressure in step (2), granulation in a granulator is selected, and the particle size of the granules is 3.8 mm.

[0055] The manganese dioxide is purchased from Sinopharm (Shanghai Test).

[0056] Comparative Example 2

[0057] The specific implementation of the embodiment is the same as that of Example 1, except that the chemical wastewater treatment catalyst comprises, in mass percentage, alumina 32%, titanium dioxide 6%, iron oxide 12%, and coconut shell activated carbon powder to make up the balance.

[0058] In the preparation method, instead of extruding under mechanical pressure in step (2), granulation in a granulator is selected, and the particle size of the granules is 4.1 mm.

[0059] Performance evaluation

[0060] 20 ml of each catalyst is measured and loaded into an ozone catalytic oxidation wastewater treatment pilot test device (the catalyst loading height is 30% of the filler layer), and wastewater treatment tests containing naphtha components, light diesel components and other hydrocarbons are carried out. The ozone amount is adjusted, the OC ratio (gO3 / gCOD) is controlled to be between 2.5-3.0, 10 groups are tested for each example and comparative example, and the average value is taken, and the test results are shown in Tables 1-2.

[0061] Table 1 - Main properties of the catalyst prepared in each example

[0062]

[0063] Table 2 - Test results of catalysts prepared in each example in the ozone catalytic oxidation device

[0064]

[0065] As can be seen from Table 1, the specific surface area and mechanical strength of the water treatment catalyst obtained by the present application are both improved, the specific surface area is increased, indicating that the effective adsorption sites and active sites are increased, which is beneficial to the adsorption of organic pollutants and the activation of ozone; the mechanical strength is improved, which enhances the impact resistance and service life of the catalyst.

[0066] As can be seen from Table 2, the COD removal rate of the water treatment catalyst obtained by the present application is all higher than 86%, which is significantly higher than that of the water treatment catalyst prepared by using the prior art.

Claims

1. A chemical waste water treatment catalyst characterized by: The raw materials include, in mass percentage: 5-15% of molecular sieve, 10-60% of metal oxide, 0-20% of inorganic metal salt, and the balance of carbon material; The dry base of the molecular sieve is ≥ 95%; the specific surface area of the molecular sieve is 500 ~ 800 m 2 / g; the pore volume of the molecular sieve is 0.3 ~ 0.5 cm 3 / g, and the mesopore ratio is 40 ~ 80%. The metal oxide at least includes aluminum oxide, the inorganic metal salt is copper sulfate, and the mass ratio of the aluminum oxide to the molecular sieve and the inorganic metal salt is 18-20:12-15:10-15.

2. The chemical wastewater treatment catalyst according to claim 1, characterized by: The dry base of the alumina is ≥ 70%; the specific surface area of the alumina is 300~500 m 2 / g, and the pore volume is 0.5~1.2 cm 3 / g.

3. The chemical wastewater treatment catalyst of claim 2, wherein: The carbon material is at least one of graphene, graphene oxide, carbon nanotube, and activated carbon powder.

4. A method of preparing the chemical wastewater treatment catalyst according to claim 3, characterized by: The steps include the following steps: (1) dissolving the inorganic metal salt in water to form a weak acidic aqueous solution, then adding the aluminum oxide into the inorganic metal salt aqueous solution and stirring uniformly, then adding the molecular sieve and stirring to a gel state, crushing the block solid after drying treatment; (2) mixing the crushed material of step (1) with the remaining oxide and the carbon material, and adding the mixture into deionized water according to a mass water / powder ratio and extruding into a strip under mechanical pressure; (3) drying, breaking the strip, and roasting in a nitrogen environment, and the product is obtained after completion.

5. The method for preparing the chemical wastewater treatment catalyst according to claim 4, characterized in that: The mass water / powder ratio of the mixture to the deionized water is 1:0.8-1.

2.

6. Use of the chemical wastewater treatment catalyst according to any one of claims 1 to 3, characterized in that: The application of the chemical wastewater treatment catalyst in the recovery treatment process of the treatment research chemical wastewater and petrochemical wastewater is included.

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