Non-free radical type ozone catalyst suitable for high-salinity wastewater and preparation method of non-free radical type ozone catalyst

Abstract

The invention discloses a preparation method of a non-free radical type ozone catalyst suitable for high-salinity wastewater, which comprises the following steps: grinding silicon-aluminum-based mineral powder to 200-1200 meshes, and then drying for later use; the method comprises the following steps: uniformly mixing algae biomass of which the water content is less than 5% with silicon-aluminum-based mineral powder according to a mass ratio of (1: 5)-(1: 20), and carrying out rolling ball granulation to obtain a granular material; and drying and roasting the obtained particle material to obtain the catalyst. According to the ozone catalyst prepared by the method disclosed by the invention, algae biomass is taken as a raw material to introduce a high-activity carbon catalytic matrix and active catalytic sites of nitrogen and phosphorus atoms, so that a good way for realizing resource utilization of solid wastes is provided; meanwhile, alumina powder, natural zeolite powder and the like which are low in cost and easy to obtain are used for achieving granulation of the catalyst form and stable recovery in application, and the preparation method is easy to popularize.

Description

Technical Field

[0001] The invention relates to the technical field of catalyst preparation, and in particular to a non-free radical ozone catalyst suitable for high-salt wastewater and a preparation method thereof. Background Art

[0002] As my country's environmental management requirements continue to improve, the requirements for wastewater treatment efficiency and green and low-carbon levels are constantly increasing. Ozone catalytic oxidation is one of the most widely used sewage deep treatment technologies, and the performance of the ozone catalyst directly determines the treatment efficiency of the technology.

[0003] Currently, common ozone catalysts are mainly metal-supported catalysts, that is, metals with catalytic activity are supported on aluminum-based or silicon-aluminum-based carriers to induce ozone to generate OH· and other free radicals to oxidize pollutants in wastewater. However, when the salinity of wastewater is high, the catalytic effect of this type of catalyst is relatively poor due to the strong quenching effect of salt ions on free radicals, which is a widespread problem faced by advanced oxidation treatment of high-salinity wastewater.

[0004] Compared with metal-supported catalysts, catalysts with carbon, nitrogen and phosphorus as catalytic active components mainly induce ozone to produce active species such as singlet oxygen to oxidize pollutants in wastewater, avoiding the problem of free radical quenching. Therefore, they have high catalytic oxidation performance even for high-salt wastewater, and therefore have a wider range of applications. However, the preparation and production of this type of catalyst is currently limited by raw materials and preparation processes and has not yet been promoted.

[0005] Algae are common autotrophic organisms in aquatic environments and play an important role as producers in aquatic ecosystems. Algae cells absorb nutrients such as nitrogen and phosphorus in water and carbon dioxide in the air to synthesize cell substances. They naturally have carbon, nitrogen, and phosphorus elements and specific cell structures. The sources of algae biomass are very wide. my country salvages and collects a large amount of algae biomass from water bodies of water blooms every year. In order to avoid the outbreak of water blooms, the nitrogen and phosphorus in the water can be removed in advance through algae pre-cultivation pools. In addition to naturally obtaining algae biomass, the scale and prospects of artificial cultivation of algae are also expanding. For example, in the energy production or food processing industry, algae are used to produce biomass energy products such as biodiesel, or high-value health products such as algae protein and astaxanthin. After the production and extraction of these products, a large amount of algae residue will remain. The direct discharge of algae residue into the environment will have an impact on the ecological environment, and harmless treatment requires more costs. Therefore, how to achieve the recycling of water bloom algae and industrial algae residue is also a problem that needs to be solved.

[0006] Although the direct sintering of algae cells to prepare powdered ozone catalysts can achieve excellent catalytic effects, the powdered catalysts are not convenient to recycle and are difficult to apply in actual projects. How to ensure the catalytic effect while making the ozone catalysts prepared from algae biomass have reliable structural performance and mechanical strength is the basic prerequisite for realizing engineering applications. Summary of the invention

[0007] The purpose of the present invention is to provide a non-radical ozone catalyst suitable for high-salt wastewater and a preparation method thereof, which utilizes algae cells as a carbon catalytic matrix and provides nitrogen and phosphorus active sites, and uses alumina or natural zeolite as a silicon-aluminum base. The prepared granular ozone catalyst has the excellent characteristics of high salt resistance, strong activity, low cost, easy recovery and stable performance.

[0008] In order to achieve the above object, the present invention is specifically implemented through the following technical solutions:

[0009] A method for preparing a non-radical ozone catalyst suitable for high-salinity wastewater comprises the following steps:

[0010] S1, grinding the silicon-aluminum-based mineral powder to 200-1200 mesh, and then drying at 105-120° C. for standby use;

[0011] S2, mixing algae biomass with a moisture content of less than 5% and silicon-aluminum-based mineral powder in a mass ratio of 1:5 to 1:20, and granulating by rolling balls to obtain granular materials;

[0012] S3. Dry the obtained granular material at 60-80° C. for 12-24 h, and then calcine at 500-800° C. in nitrogen, argon or vacuum atmosphere for 3-5 h.

[0013] Based on the above technical solution, the algae biomass comes from natural water bodies or artificially cultured blue algae, green algae, diatoms and other organisms.

[0014] Based on the above technical solution, the algae biomass comes from the algae residue left after extracting some components from algae, such as extracting oil, protein or other biological products, and the moisture content is less than 5%. When using the algae residue left after extracting oil, protein or other biological products, if the moisture content of the algae residue is sufficiently lower than 5%, dehydration and drying can be omitted, and the moisture content can be ensured to be below 5%.

[0015] Based on the above technical solution, the silicon-aluminum-based mineral powder is one or more of alumina powder, natural zeolite and activated diatomaceous earth.

[0016] On the basis of the above technical solution, the activation method of the activated diatomite is that the diatomite is fully alkalized in a sodium hydroxide solution, filtered, washed with clean water, and then calcined for activation.

[0017] The present invention also provides a non-radical ozone catalyst suitable for high-salt wastewater, which is prepared by the above-mentioned preparation method of the non-radical ozone catalyst suitable for high-salt wastewater.

[0018] The ozone catalyst prepared by the method of the present invention uses algae biomass as raw material to introduce a highly active carbon catalytic matrix and active catalytic sites of nitrogen and phosphorus atoms, thereby overcoming the problem that metal-supported catalysts have poor catalytic effects on high-salt wastewater; the algae residue raw material used can come from water bloom algae, or from algae biomass diesel and algae residue remaining after the extraction of high-value biomass products, which is a good way to realize the resource utilization of solid waste; while obtaining algae biomass raw materials through these approaches, the management and protection of the water environment is also achieved.

[0019] Alumina, zeolite, diatomaceous earth and other materials are used to provide a silicon / aluminum base, which is mixed with algae cells to prepare granular catalysts. Through scientific preparation and processing technology, it can provide reliable structural performance and mechanical strength while ensuring the catalytic effect, thereby achieving efficient recovery of the catalyst and stable catalytic performance.

[0020] Using algae cells as raw materials for preparing ozone catalysts can directly introduce highly catalytically active carbon matrices and nitrogen and phosphorus active sites; using algae cells to provide catalyst active components eliminates the need for high-priced metal raw materials, thereby further reducing the production cost of ozone catalysts; at the same time, using cheap and readily available alumina powder, natural zeolite powder, etc. to achieve catalyst granulation and stable recovery in application, the preparation method is novel, simple, and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a comparison chart of TOC removal effect between the embodiment of the present invention and the comparative example. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0023] The present invention provides a method for preparing a non-free radical ozone catalyst suitable for high-salt wastewater, comprising the following steps:

[0024] S1. Grind the silicon-aluminum-based mineral powder to 200-1200 mesh, and then dry it at 105-120° C. for more than 24 hours for standby use; in this step, the silicon-aluminum-based mineral powder is preferably alumina powder or natural zeolite powder.

[0025] S2. Evenly mix algae biomass with a moisture content of less than 5% and silicon-aluminum-based mineral powder in a mass ratio of 1:5 to 1:20, and granulate them by rolling balls to obtain granular materials; the algae biomass comes from organisms such as natural water bodies or artificially cultivated blue algae, green algae, diatoms, etc., or the remaining algae residue after the extraction of some components, and the moisture content is ensured to be below 5%.

[0026] S3, drying the granular material obtained in step S2 at 60-80° C. for 12-24 h, and then calcining at 500-800° C. in nitrogen, argon or vacuum atmosphere for 3-5 h to obtain.

[0027] Example 1

[0028] The preparation method of the granular ozone catalyst of the present invention comprises raw materials including: bloom algae (mainly cyanobacteria, including green algae, Chlamydomonas, etc.) and alumina powder. The preparation method is as follows:

[0029] S1. Dehydrating and drying the algae biomass salvaged from the water body of the algae bloom to reduce its moisture content to less than 5%;

[0030] S2, drying the alumina powder ground to 200-1200 mesh at 105-120°C for later use;

[0031] S3, mixing the algae biomass treated in step S1 and the alumina powder in step S2 in a mass ratio of 1:5, and granulating by rolling balls to obtain a granular material;

[0032] S4. Dry the granular material at 60°C for 24 hours, and then calcine at 500°C in nitrogen, argon or vacuum atmosphere for 5 hours.

[0033] Example 2

[0034] The preparation method of the granular ozone catalyst of the present invention comprises raw materials including: Chlorella and natural zeolite powder. The preparation method is as follows:

[0035] S1, dehydrating and drying the Chlorella vulgaris to reduce its moisture content to below 5%, thereby obtaining algae biomass;

[0036] S2, grinding the natural zeolite powder to 200-1200 mesh and drying it at 105-120°C for later use;

[0037] S3, fully and uniformly mixing the algae biomass and the natural zeolite powder, wherein the mixing mass ratio of the algae biomass to the natural zeolite powder is 1:10, and granulating by rolling ball;

[0038] S4. Dry the prepared particles at 80°C for 12 h, and then calcine at 800°C for 3 h in a nitrogen, argon or vacuum atmosphere.

[0039] Example 3

[0040] The preparation method of the granular ozone catalyst of the present invention comprises the following raw materials: algae biomass, mixed algae from algae culture ponds for deep treatment of nitrogen and phosphorus removal in sewage treatment plants, including Scenedesmus, Chlorella, etc.; alumina powder, natural zeolite powder. The preparation method is as follows:

[0041] S1. Use sludge dewatering facilities on site at the sewage treatment plant to filter-filter dehydrate and dry the algae biomass to reduce its moisture content to less than 5%;

[0042] S2, grinding the alumina powder and natural zeolite powder to 200-1200 mesh and drying them at 105-120° C. for later use;

[0043] S3, mixing the treated algae biomass, alumina powder and natural zeolite powder evenly (mixing mass ratio is 1:5:4), and granulating by rolling ball to obtain granular material;

[0044] S4. Dry the granular material at 65°C for 20 hours, and calcine at 800°C in nitrogen, argon or vacuum atmosphere for 3 hours.

[0045] Example 4

[0046] The preparation method of the granular ozone catalyst of the present invention comprises the following raw materials: algae biomass, mixed algae from algae culture ponds for deep treatment of nitrogen and phosphorus removal in sewage treatment plants, including Scenedesmus, Chlorella, etc.; alumina powder, diatomaceous earth. The preparation method is as follows:

[0047] S1. Use sludge dewatering facilities on site at the sewage treatment plant to filter-filter dehydrate and dry the algae biomass to reduce its moisture content to less than 5%;

[0048] S2, fully grinding the aluminum oxide powder to 200-1200 mesh, and drying at 105-120° C. for standby use;

[0049] S3, fully alkalize the diatomaceous earth in a sodium hydroxide solution, filter it, wash it with clean water, and then roast it for activation;

[0050] S4, fully and uniformly mixing the algae biomass, alumina powder and natural zeolite powder, wherein the mixing mass ratio of the algae biomass, alumina powder and natural zeolite powder is 1:3:6, and granulating by rolling ball to obtain a granular material;

[0051] S5. Dry the prepared granular material at 80° C. for 10 h, and then calcine at 800° C. in a nitrogen, argon or vacuum atmosphere for 5 h.

[0052] Example 5

[0053] The preparation method of the granular ozone catalyst of the present invention comprises the following raw materials: algae biomass, algae residue (water content less than 5%) after oil is extracted from Chlorella vulgaris; and alumina powder. The preparation method is as follows:

[0054] S1, drying the 200-1200 mesh ground alumina powder at 105-120°C for later use;

[0055] S2, fully mixing the Chlorella algae residue and the alumina powder, wherein the Chlorella algae residue and the alumina powder are mixed in a mass ratio of 1:12, and granulating by rolling ball to obtain a granular material;

[0056] S3. Dry the prepared granular material at 75°C for 15 hours, and calcine at 650°C in nitrogen, argon or vacuum atmosphere for 4 hours.

[0057] Example 6

[0058] The preparation method of the granular ozone catalyst of the present invention comprises raw materials including: spirulina residue (water content less than 5%) after phycocyanin is extracted from spirulina; and alumina powder. The preparation method is as follows:

[0059] S1, grinding the alumina powder to 200-1200 mesh and drying it at 105-120°C for later use;

[0060] S2, mixing the spirulina algae residue and the alumina powder evenly, the mass ratio of the spirulina algae residue to the alumina powder is 1:15), and granulating by rolling ball to obtain a granular material;

[0061] S3. Dry the prepared granular material at 80°C for 12 hours, and then calcine at 500°C in nitrogen, argon or vacuum atmosphere for 5 hours.

[0062] Example 7

[0063] The preparation method of the granular ozone catalyst of the present invention comprises raw materials including algae residue (water content less than 5%) after astaxanthin is extracted from Haematococcus pluvialis and natural zeolite powder.

[0064] The preparation method is as follows:

[0065] S1, drying the ground (200-1200 mesh) natural zeolite powder at 105-120°C for later use;

[0066] S2, mixing the Haematococcus pluvialis algae residue and natural zeolite powder evenly (mixing ratio 1:8), and rolling granulation;

[0067] S3. Dry the prepared granular material at 60°C for 24 hours, and then calcine at 550°C in nitrogen, argon or vacuum atmosphere for 5 hours.

[0068] Example 8

[0069] The preparation method of the granular ozone catalyst of the present invention comprises raw materials including: bloom algae (mainly cyanobacteria, including green algae, Chlamydomonas, etc.), algae residue after oil is extracted from Chlorella (water content is less than 5%); alumina powder and natural zeolite powder.

[0070] The preparation method is as follows:

[0071] S1. Dehydrating and drying the algae biomass salvaged from the water body of the algae bloom to reduce its moisture content to less than 5%;

[0072] S2, drying the ground (200-1200 mesh) alumina powder and natural zeolite powder at 105-120°C for later use;

[0073] S3, fully and uniformly mixing the bloom algae powder, Chlorella algae residue, alumina powder and natural zeolite powder, wherein the bloom algae powder, Chlorella algae residue, alumina powder and natural zeolite powder are mixed in a mass ratio of 1:1:10:10, and granulating by rolling ball to obtain a granular material;

[0074] S4. Dry the prepared granular material at 65°C for 20 hours, and then calcine at 600°C in nitrogen, argon or vacuum atmosphere for 4 hours.

[0075] Comparative Example 1

[0076] Existing commercial ozone catalysts are supported by alumina and have metals as active components.

[0077] Comparative Example 2

[0078] A metal-based ozone catalyst, the catalyst raw materials include: 94% aluminum oxide powder and 6% manganese oxide. The preparation method is as follows:

[0079] S1, mixing the ground and dried catalyst carrier and active components uniformly;

[0080] S2, placing in a granulator for granulation, adding acetic acid of a certain volume concentration until particles with a uniform particle size of 3 to 4 mm are formed;

[0081] S3. Dry the prepared particles at 120° C. for 12 h, and then calcine at 500° C. in air atmosphere for 3 h.

[0082] Comparative test:

[0083] The above catalyst (Examples 1 to 8, Comparative Examples 1 to 2) was used to deeply treat a certain petrochemical wastewater by ozone catalytic oxidation. The ozone concentration was 3 mg / L, the flow rate was 100 ml / min, the oxidation time was 30 min, the influent TOC concentration was 12.41 mg / L, and the TOC removal rate was as follows: Figure 1 shown.

[0084] Under the same conditions, the TOC removal rate of the ozone catalyst of the present invention is above 50% compared with the raw water. The removal rates of Comparative Examples 1 and 2 are up to 36%, especially compared with the ozone catalyst of Comparative Example 2 without adding algae biomass, the performance of the ozone catalyst based on algae biomass in wastewater treatment of the present invention is significantly improved compared with Comparative Examples 1 and 2, indicating that the product has good activity and good effect in ozone catalytic oxidation.

[0085] The specific embodiments of the present invention are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, such modifications are protected by the patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing a non-radical ozone catalyst suitable for high-salt wastewater, characterized in that: The following steps are involved: S1. Grind the silicon-aluminum-based mineral powder to 200-1200 mesh, and then dry it at 105-120° C. for more than 24 hours for standby use; S2, mixing algae biomass with a moisture content of less than 5% and silicon-aluminum-based mineral powder in a mass ratio of 1:5 to 1:20, and granulating by rolling balls to obtain granular materials; S3. Dry the granular material at 60-80°C for 12-24 hours, and then calcine at 500-800°C in nitrogen, argon or vacuum atmosphere for 3-5 hours to obtain.

2. The non-radical ozone catalyst suitable for high-salt wastewater and its preparation method according to claim 1, characterized in that: The algae biomass comes from natural water bodies or artificially cultivated blue algae, green algae, diatoms and other organisms, and is dehydrated and dried to a moisture content of less than 5%.

3. The non-radical ozone catalyst suitable for high-salt wastewater and the preparation method thereof according to claim 1, characterized in that: The algae biomass comes from the remaining algae residue after extracting some components from algae, and has a water content of less than 5%.

4. The non-radical ozone catalyst suitable for high-salt wastewater and the preparation method thereof according to claim 1, characterized in that: The silicon-aluminum-based mineral powder is one or more of aluminum oxide powder, natural zeolite and activated diatomaceous earth.

5. The non-radical ozone catalyst suitable for high-salt wastewater and the preparation method thereof according to claim 4, characterized in that: The activation method of the activated diatomite is that the diatomite is fully alkalized in a sodium hydroxide solution, filtered, washed with clean water, and then calcined for activation.

6. A non-radical ozone catalyst suitable for high-salt wastewater prepared by the preparation method of the non-radical ozone catalyst suitable for high-salt wastewater according to claims 1-5.

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